monensin and Body-Weight

A meta-analysis of the impact of monensin on production outcomes in dairy cattle was conducted using the 36 papers and 77 trials that contained eligible data. Statistical analyses were conducted in STATA and included a consideration of fixed or random effects models, assessment of publication bias, and impact of influential studies. Meta-regression was used to investigate sources of heterogeneity of response. There were 71 trials containing data from 255 trial sites and 9,677 cows examining milk production and composition. Monensin use in lactating dairy cattle significantly decreased dry matter intake by 0.3 kg, but increased milk yield by 0.7 kg and improved milk production efficiency by 2.5%. Monensin decreased milk fat percentage 0.13%, but had no effect on milk fat yield; however, there was significant heterogeneity between studies for both of these responses. Milk protein percentage was decreased 0.03%, but protein yield was increased 0.016 kg/d with treatment. Monensin had no effect on milk lactose percentage. Monensin increased body condition score by 0.03 and similarly improved body weight change (0.06 kg/d). Analysis of milk fatty acid profile data indicated that monensin was associated with a reduction of short-chain fatty acids (from 1 to 12% reduction) and stearic acid (-7.8%). The impact of monensin on linoleic and linolenic acids was variable, but monensin significantly increased conjugated linoleic acid (22%). Meta-regression of the effect of monensin on milk component percentages and yields indicated an influence of delivery method, stage of lactation, dose, and diet. Increasing concentrations of C18:1 in the diet enhanced the effect of monensin on decreasing milk fat yield, whereas increasing the rumen peptide balance increased the effect of monensin on milk protein yield. These findings indicate a benefit of monensin for improving milk production efficiency while maintaining body condition. The effect of monensin on milk fat percentage and yield was influenced by diet.

Topics: Animal Nutritional Physiological Phenomena; Animals; Body Constitution; Body Weight; Cattle; Dairying; Diet; Eating; Fats; Female; Ionophores; Lactation; Milk; Milk Proteins; Monensin

In a study of the possible introduction of Japanese field vole (Microtus montebelli ) and Hungarian voles (M. arvalis) as herbivorous experimental animals, the following biological characteristics were investigated: breeding and reproductive performance; bacterial flora and fermentation in the digestive tracts; and nutritional physiology. The animals are polyestrus , show postpartum estrus on the day of parturition, and there is little or no delay in implantation due to lactation, especially in M. arvalis. On examination of vaginal smears, Japanese field vole did not show any definite pattern, whereas most Hungarian voles showed 6- to 18- day cycles. From the esophageal sac of voles fed rations with a high fiber content, cellulolytic bacteria similar to Ruminococcus albus, Ruminococcus flavefaciens , and Bacteroides succinogenes were isolated. More than 1 000 000/g anaerobic bacteria were present in the esophageal sac and the pattern and the types of bacteria resembled those found in the rumen. Gastric fermentation took place in the esophageal sac. The pH and total VFAs were much smaller in the fundic and pyloric regions of the stomach than in the esophageal sac. Acetic and lactic acids were the major fermentation products in the esophageal sac. Following deficiency or lowering of the cellulose decomposing abilities, a decrease of VFAs and an increase in lactic acid production in the esophageal sac were observed. These effects resulted in high glucose, FFA and ketone bodies in the blood, and a higher incidence of glucosuria. Diabetes induced by administrations of drugs such as alloxan, streptozotocin and phloridzin were compared using Microtus and mice. Microtus had low sensitivity to alloxan but high sensitivity to streptozotocin. The influence of monensin on Microtus was also investigated by using diets containing 20 and 80 mg/kg monensin. Diets containing 80 mg/kg monensin led to 50 % mortality in 7 weeks and growth was hindered. Gas production from the esophageal sac contents of voles in the monensin-medicated group was much smaller than that of the non-medicated group. In the monensin group the total VFA concentrations of the esophageal sac contents was decreased.

Topics: Animal Nutritional Physiological Phenomena; Animals; Animals, Wild; Arvicolinae; Bacteria; Body Weight; Breeding; Diabetes Mellitus, Experimental; Diet; Digestive System; Fatty Acids, Volatile; Female; Fermentation; Hydrogen-Ion Concentration; Male; Mice; Monensin; Pregnancy; Reproduction

Carboxylic polyether ionophores, when fed to growing ruminants improve efficiency of production. This review summarizes the observed effects of ionophores on the ruminal fermentation and the host animal. The effect of ionophores on prokaryotic and eukaryotic cells is described and this knowledge is then utilized to explain many of the observed ionophore effects on the rumen fermentations and host gastrointestinal physiology.

Topics: Animal Diseases; Animals; Animals, Domestic; Artiodactyla; Bacteria; Biological Transport, Active; Body Weight; Cattle; Electron Transport; Energy Metabolism; Eukaryota; Fermentation; Food Additives; Ionophores; Lasalocid; Membrane Potentials; Models, Chemical; Monensin; Nitrogen; Rumen

Monensin has been tested to determine its toxicity and safety in cattle. Single dose acute toxicity and signs associated with toxicity were determined by oral gavage, 7-d oral gavage and feeding experiments with high concentrations of monensin in feed. Oral feeding studies indicated a near complete anorexia resulting from intake of sublethal amounts of monensin. In these cases, cattle recovered from the insulting dose and resumed growth and feed intake. In long-term chronic feedlot, pasture supplement, and reproduction safety studies conducted with monensin administered in the feed, the high concentrations caused cattle to show signs of mild monensin intoxication. Mortality resulted from feeding groups of cattle large quantities of monensin in small quantities of feed. Furthermore, these studies have demonstrated no detrimental effects upon reproduction. Collectively, these studies indicate that the greatest risk of intoxication occurs when cattle first receive a feed containing monensin. Mixing errors and misuse situations under actual use conditions have resulted in cases of cattle mortality. In most cases the mortality was predictable based upon the exposure in controlled studies.

Topics: Animals; Anorexia; Body Weight; Cattle; Cattle Diseases; Eating; Female; Food, Fortified; Furans; Male; Monensin; Reproduction

Performance data on nearly 16,000 head of cattle that were used in trials to document effects of monensin on feedlot cattle were summarized. Cattle fed monensin-containing diets gained 1.6% faster, consumed 6.4% less feed and required 7.5% less feed/100 kg gain than cattle fed control diets. Monensin resulted in the greatest improvement in feed/gain at 2.9 Mcal metabolizable energy (ME)/kg diet dry matter (DM). Within the range of monensin concentrations used in the trials that were summarized (31.8 +/- 7.5 mg/kg DM), high monensin concentrations did not improve feed/gain over that obtained with lower concentrations. Carcass characteristics were not significantly influenced by monensin. Responses of cattle to monensin and implants were additive. Energy metabolism data suggested that monensin improved digestibility of DM, reduced fasting heat production and increased dietary net energy maintenance (NEm) values more than it increased net energy gain (NEg) values. Data showing the response of cattle to monensin when fed various dietary protein concentrations or sources of supplemental N suggested that monensin had a protein sparing effect. Monensin has also been shown to reduce lactic acid production, aid in the control of coccidia and bloat and to be toxic to face and horn fly larva in feces of monensin-fed cattle. In pasture trials, monensin improved daily gains. When fed to beef cows, monensin reduced amounts of feed required to maintain cow weight.

Topics: Acidosis; Animals; Body Weight; Cattle; Cattle Diseases; Coccidiosis; Dietary Proteins; Drug Implants; Energy Metabolism; Female; Food Additives; Furans; Lactates; Male; Models, Biological; Monensin; Nitrogen; Stomach Diseases

The objective was to evaluate the effect of using prebiotics (Saccharomyces cerevisiae boulardii) or Monensin in the confinement initial phase and replacing monensin with probiotics (Bacillus toyonensis) in the final phase. Forty-eight Nellore steers were used, with an initial mean body weight of 356.2 ± 17.98 kg, distributed in a completely randomized design. Two animals per pen were confined in 80 m

Topics: Animal Feed; Animals; Bacillus; Body Weight; Cattle; Diet; Male; Monensin; Prebiotics; Probiotics; Saccharomyces cerevisiae

To understand the metabolic mechanisms regulating lipid metabolism by monensin, Afshari male lambs (n = 16) with 41.0 ± 2.4 kg body weight (BW, mean ± SD) at approximately 180 days of age were randomly assigned equally to two dietary treatments. After a 21-day pre-adaptation period, all animals in two groups continued to receive the basal diet, but one group received no monensin supplementation (control) while the other group received 30 mg/day of monensin per animal. Individual BW was recorded weekly to determine the average daily body weight gain (ADG). At the end of the 56-day experimental period, lambs were weighed and slaughtered. Monensin supplementation did not affect BW, ADG, and rumen fermentation characteristics. However, monensin significantly downregulated the sterol regulatory element-binding protein (SREBP)-2 gene expression in all sample tissues (p < 0.05). Also, monensin downregulated expressions of SREBP-1c and peroxisome proliferator-activated receptor (PPAR)-γ in back fat tissues. Monensin increased the expression of 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS)-2, but it decreased the mRNA abundance of HMGCS-1 in the rumen epithelial tissues (p < 0.05). Our data suggest that monensin downregulates cholesterol synthesis via inhibition of HMGCS-1 and impairment of the SREBP pathway, probably due to a crosstalk among different tissues to control energy metabolism.

Topics: Adipose Tissue; Animal Feed; Animals; Body Weight; Cholesterol; Diet; Dietary Supplements; Epithelium; Male; Monensin; Rumen; Sheep; Sheep, Domestic; Sterol Regulatory Element Binding Protein 1

Gut health is critically important for growing neonatal calves, and nutritional technologies are needed to prevent disease and stress challenges. Previous work feeding monensin (MON) in combination with an oregano, prebiotic, and cobalt-lactate (EOC) blend had demonstrated improved calf gut health and growth performance. The objective of this study was to evaluate the growth performance of calves fed MON and EOC alone or in combination. Eighty (80) newborn Holstein (37) female and (43) male calves were randomly assigned to one of four treatments arranged in a 2 × 2 factorial (MON and EOC). Treatments were: 1) Control: without MON or EOC added to the calf starter (CS); 2) MON: 50.8 mg/kg CS (Elanco, Greenfield, IN); 3) EOC: 44.1 mg/kg CS (Rum-A-Fresh, Ralco Inc. Marshall, MN); 4) MON + EOC: MON and EOC added to CS. Calves were fed colostrum followed by whole milk through weaning at 42 d, while CS was fed ad libitum through the 70-d experimental period. The MON by EOC interaction was found to be nonsignificant (P > 0.41) for growth performance. Calves fed without or with MON demonstrated similar (P > 0.70) body weight (BW; 68.7 and 68.9 kg without and with MON, respectively), while calves fed EOC demonstrated greater (P < 0.01) BW (67.3 and 70.4 kg without and with EOC, respectively) compared with calves fed without EOC. Calves fed a CS containing MON were similar (P > 0.47) in average daily gain (ADG; 0.88 and 0.91 kg/d) compared with calves fed without MON; however, feeding calves a CS with EOC increased (P < 0.01) ADG (0.84 and 0.95 kg/d) by 13% through the 70-d experimental period compared with calves not fed EOC. Frame measurements indicated that the greater ADG was due to increased (P < 0.10) frame growth for calves fed essential oils (EO) compared with calves fed without EO. A MON by EOC interaction (P < 0.01) for serum propionate concentration demonstrated calves fed MON + EOC and EOC were greater (P < 0.05) compared with calves fed Control, while calves fed MON were intermediate and different (P < 0.05). Feeding calves a CS with EOC increased (P < 0.04) immunoglobulin A, immunoglobulin G, and immunoglobulin M concentrations compared with calves fed without EOC. A MON by EOC interaction was detected (P < 0.01) for total tract starch digestibility for calves fed EOC or MON + EOC demonstrating greater (P < 0.05) starch digestibilities than Control-fed calves. These data demonstrate that EOC and MON fed in combination was not beneficial for enhancing t

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Body Weight; Cattle; Cobalt; Colostrum; Diet; Female; Male; Milk; Monensin; Oils, Volatile; Origanum; Prebiotics; Pregnancy; Starch

Topics: Acrolein; Animal Feed; Animals; Blood Urea Nitrogen; Body Weight; Cattle; Diet; Female; Monensin; Weaning

Two experiments were designed to investigate the effects of feeding monensin and/or slow release urea with a fibrolytic feed enzyme (Optimase; Alltech, Inc., Nicholasville, KY) on performance, milk production, calf growth performance, and blood metabolites in beef cows. Spring-calving cows and heifers were used in a completely randomized design in Exp. 1 (N = 84; 534 ± 68 kg initial BW) and Exp. 2 (N = 107; 508 ± 72 kg initial BW). Exp. 1 supplements were formulated to meet cow protein requirements and fed daily and included 1) cottonseed meal with no monensin (control); or 2) monensin added to control to supply 200 mg per head per d (MON). In Exp. 2, experimental supplements included 1) cottonseed meal/wheat middlings (CS) fed at a rate to provide adequate DIP and CP according to , 2) the CS plus soybean hulls and 61 g per cow per d Optimase (OPT), 3) the CS plus monensin to supply 200 mg per cow per d (MON2), and 4) OPT plus MON2 (Combo). Cows were fed in last trimester through early lactation in Exp. 1 and during 2nd trimester in Exp. 2. Data were analyzed using the Mixed procedure in SAS with animal as the experimental unit. In Exp. 1, treatment did not affect cow BW or BCS change (P > 0.19). Calf birth BW was not affected by dam treatment (P = 0.24); however, calves from dams consuming MON weighed more (P < 0.04) at d 45 and at trial end. Calves also had greater (P = 0.04) ADG from birth to trial end. Milk production did not significantly differ among treatments (P > 0.41). In Exp. 2, mean cow BW and BCS were similar (P > 0.35) among treatments on d 90. However, from d 0 to 54, cows assigned to the OPT supplement gained less BCS (P = 0.02) compared with cows assigned to the CS supplement. Cumulative BCS gain was greater (P < 0.01) for CS-fed cows than for cows fed the OPT and MON2 supplements, although it was not significantly different for cows fed the Combo supplement. These studies indicate that the influence of monensin on cow BW and BCS change is inconsistent. The potential for monensin supplementation to positively impact calf performance during early lactation seems to be clearer. Replacing a portion of oilseed N in the supplement with Optimase may marginally reduce cow performance. Further research is needed to determine both the effects of monensin and the implications of combining monensin with Optimase on forage intake and cow performance at various stages of production.

Topics: Animal Feed; Animals; Animals, Newborn; Blood Glucose; Blood Urea Nitrogen; Body Weight; Cattle; Dietary Supplements; Edible Grain; Enzymes; Female; Lactation; Milk; Monensin; Pregnancy; Pregnancy, Animal; Urea

Coccidiosis is the most important parasitic disease of the poultry production industry. Due to increasing resistance to conventional anticoccidial agents, it is necessary to find new anticoccidial compounds. Herbal compounds such as those from Artemisia species are promising weapons in this regard since preliminary studies have shown its anticoccidial effects. To compare the anticoccidial effect of a granulated extract of Artemisia sieberi (GEAS) versus monensin in experimental broiler coccidiosis, 120 one-day old Ross 308 broiler chickens were divided in four groups, each with three replicates (n=10). Group 1 was separated as an uninfected negative control and received no treatment. At 21days of age, groups 2, 3 and 4 were inoculated with a mixed suspension of 2×10(5) oocysts of Eimeria tenella, Eimeria maxima, Eimeria acervulina and Eimeria necatrix. Group 2 was maintained as an infected positive control and received no treatment while groups 3 and 4 received GEAS (5mg/kg feed), and monensin (110mg/kg feed) from the first day until 42days of age as a feed additive, respectively. Five days after inoculation, the number of oocycts per gram (OPG) of feces for 7 successive days was measured. Also, mean body weight (MBW), weight gain (WG), feed intake (FI) and feed conversion ratio (FCR) were determined weekly in all groups and replicates. The results showed that GEAS and monensin improved performance attributes (FI, MBW, WG, FCR) and significantly (P<0.05) decreased OPG in inoculated broiler chickens.

Topics: Animals; Artemisia; Body Weight; Chickens; Coccidiosis; Coccidiostats; Eating; Feces; Monensin; Oocysts; Parasite Egg Count; Plant Extracts; Poultry Diseases

The objective of this study was to evaluate conventional (CONV) and natural (NAT) beef production systems from annual pasture through finishing through grazing. Beef steers (n=180, initial BW=250±19 kg) were assigned randomly to 2 treatments in the pasture phase. Steers were implanted with 40 mg of trenbolone acetate (TBA), 8 mg estradiol, and 29 mg tylosin tartrate (CONV), or received no implant (NAT). Steers on the 2 treatments grazed wheat or cereal rye for 109 d. Conventional steers had an 18.5% improvement in ADG (1.22 vs. 1.03 kg/d, P<0.01) and a heavier final BW (385 vs. 366 kg, P<0.01) compared with NAT steers. Following the pasture phase, steers (n=160 steers, 5 steers/pen, 8 pens/treatment) were assigned to a 2×2 factorial in the feedlot phase. Production system (NAT vs. CONV) was maintained from the pasture phase, and the second factor was 7 vs. 12% low-quality roughage (DM basis, LOW vs. HIGH). During finishing, CONV steers were given 120 mg of TBA and 24 mg estradiol at processing, fed monensin and tylosin, and fed zilpaterol hydrochloride for the last 20 d of the experiment. There were no program×roughage level interactions (P>0.07). The CONV steers ate 6.9% more feed (11.8 vs. 11.0 kg/d, P<0.01), gained 28.4% faster (1.90 vs. 1.48 kg/d, P<0.01), and were 24.2% more efficient (0.164 vs. 0.132, P<0.01) compared with NAT steers. The LOW steers had greater G:F (0.153 vs. 0.144, P<0.01) compared with HIGH steers. There was a 28.3% improvement in estimated carcass weight gain (1.36 vs. 1.06 kg/d), 18.6% improvement in carcass efficiency (0.115 vs. 0.097, P<0.01), and 21.6% improvement (1.52 vs. 1.25 Mcal/kg, P<0.01) in calculated dietary NEg for CONV compared with NAT steers. Hot carcass weight was increased by 62 kg (424 vs. 362 kg, P<0.01) and LM area was increased by 16.9 cm2 (100.9 vs. 84.0 cm2, P<0.01), decreasing USDA yield grade (YG, 3.09 vs. 3.54, P<0.01) for CONV steers compared with NAT steers. Natural steers had a greater percentage of carcasses in the upper 2/3 of USDA Choice grade (48.7 vs. 18.7%, P<0.01), a greater percentage of YG 4 and 5 carcasses (25.4 vs. 9.3%, P<0.01), and a greater percentage of abscessed livers (39.6 vs. 10.5%, P<0.01) compared with CONV steers. The results show that CONV production results in more rapid and efficient production that resulted in heavier carcasses with superior YG and desirable quality grades with both roughage levels.

Topics: Animal Feed; Animal Husbandry; Animals; Body Composition; Body Weight; Cattle; Estradiol; Male; Meat; Monensin; Random Allocation; Trenbolone Acetate; Trimethylsilyl Compounds; Tylosin; Weight Gain

Twenty-four Holstein dairy cows were used to evaluate the singular and combined effects of different level of crude protein and monensin treatments during the early lactation on digestion and milk yield of dairy cows. The experiment was designed as completely randomized with a 3x2 factorial arrangement of treatments. The factors were three Concentrations of CP supplement (19.5, 21.4 and 23.4% of dry matter) and two levels of monensin (0 and 350 mg per cow per day). This experiment consist of three periods and each period was 3 week in length. Monensin did not affect DMI, milk yield, lactose and SNF but it reduced milk fat and protein percentage. Monensin premix significantly decreased rumen ammonia but rumen pH and microbial protein synthesis was not affected by monensin treatment. Although, Monensin treatment increased apparent digestibility of DM, NDF, ADF, CP, but they were not significantly. Increasing dietary CP, improved milk and protein production, but did not alter the other components of milk. Digestibility of NDF, ADF, CP were improved by increasing dietary CP. Increasing diet CP from 19.5 to 21.4% did not significantly increase ruminal ammonia, but increasing to 23.4% have significant effect on it. There was a linear relationship between level of crud protein in the diet and urine volume excretion. Microbial protein synthesis was affected by increasing CP level; on this way maximum protein synthesis was achieved in 21.4% CP.

Topics: Animals; Body Weight; Cattle; Dairying; Digestion; Female; Hydrogen-Ion Concentration; Lactation; Milk; Milk Proteins; Monensin; Time Factors; Urine

Cows from three herds calving in spring that were fed on pasture were paired by herd, production index, predicted calving date, and age. One cow from each pair was allocated randomly to the treatment group and received a controlled-release capsule of monensin 1 mo prior to the start of AI. A random sample of 20 matched pairs of cows was selected within each herd to monitor BW and metabolic parameters. Treated cows produced more fat, protein, and liters of milk per day during the 2nd mo of monensin activity and produced a greater total milk volume than did control cows. Treated cows gained less BW during the 1st mo after treatment. No significant differences were identified in submission rates, overall pregnancy rates, or pregnancy rate to first or second AI. Blood urea nitrogen was elevated in the treatment group as a main effect, and NEFA were elevated in the 2nd and 3rd mo after treatment. There was no significant effect on blood concentrations of glucose, albumin, or BHBA.

Topics: 3-Hydroxybutyric Acid; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Body Weight; Cattle; Fatty Acids, Nonesterified; Female; Hydroxybutyrates; Lactation; Monensin; Pregnancy; Reproduction; Rumen; Serum Albumin

Three trials were conducted to evaluate the efficacy of laidlomycin propionate (LP) to reduce the incidence and severity of ruminal acidosis in cattle fed high-grain finishing diets. In each trial, LP was fed at 0, 6, or 12 mg/kg of diet DM. In two acidosis-challenge trials, ruminally fistulated steers were fed (DM basis) a 50% concentrate diet and then fed a 95% concentrate diet at a specific intake (2.75% BW) or steers were dosed intraruminally with a 100% concentrate diet. Laidlomycin propionate did not alter ruminal pH or total acid concentrations, but in Trial 1 the 6 mg/kg level altered (P < .10) the molar proportions of the acids, increasing total ruminal VFA and decreasing ruminal lactate. In Trial 3, a finishing trial, LP reduced (P < .10) intake day-to-day variation of individually fed steers during a 13-d adaptation period from a 65 to a 100% concentrate diet, suggesting reduced incidence of subacute acidosis. Feed intake was lower (P < .05) during the first 13 d of the trial due to LP but was not affected over the entire trial. Laidlomycin propionate improved feed efficiency (gain/feed) when calculated on a live weight basis (linear, P = .05) or carcass weight basis (linear, P = .20). Laidlomycin propionate does not prevent ruminal acidosis, but it may reduce the severity of ruminal acidosis during adaptation to a 100% concentrate diet.

Topics: Acidosis; Animal Feed; Animals; Body Composition; Body Weight; Cattle; Cattle Diseases; Diet; Hydrogen-Ion Concentration; Ionophores; Male; Monensin; Rumen; Severity of Illness Index

Monensin is an ionophoretic antibiotic, which selectively transports alkali metal cations across biological membranes. In growing swine, monensin toxicosis causes acute, degenerative cardiac and skeletal myopathy resembling vitamin E-selenium deficiency. Selenium is an essential trace element incorporated in glutathione peroxidase (GSH-Px), an antioxidant enzyme system that protects subcellular membranes. In our study, we examined the effects of monensin on body weight, Se balance, antioxidant status, and serum concentrations of selected minerals in growing pigs that were genetically hypo- or hyperselenemic (hypo-Se and hyper-Se, respectively). Three groups of eight 8-week-old pigs, each comprised of 4 hypo-Se and 4 hyper-Se pigs (76.4 +/- 3.0 and 106.3 +/- 10.3 ng of Se/ml of serum, respectively), were fed standard diets containing 0.1 mg of supplemental Se/kg of body weight, and either 0, 200, or 400 mg of monensin/kg for a 77-day period, followed by a 28-day monensin withdrawal period. On days 0, 7, 28, 56, 70, and 98, all pigs were weighed and blood was collected for determination of serum GSH-Px, creatine phosphokinase, and aspartate transaminase values, as well as serum concentrations of vitamin E, Se, Ca, Cu, Fe, K, Mg, Na, P, and Zn. Significance of main effects of monensin treatment, genetic Se status, and their interactions was tested by Fisher's variance ratio test, followed by conditional comparison of treatment means with a Bonferroni test. Signs of monensin toxicosis were not observed and monensin consumption had no effect on body weight, or serum creatine phosphokinase, aspartate transaminase, or Se values. However, pigs consuming monensin had consistently higher serum GSH-Px activities, possibly because of increased synthesis of this adaptive antioxidant enzyme. Interactions were not found between monensin and genetic Se status. Hyperselenemic pigs were heavier and had higher serum Se and GSH-Px values than hypo-Se pigs. Furthermore, hypo-Se and hyper-Se pigs were hypo- and hypercupremic, respectively, suggesting genetic regulation of copper status. It is likely that pigs with inadequate antioxidant status (hyposelenemia, hypocupremia) are more susceptible to diseases associated with cellular membrane damage, such as vitamin E-Se deficiency disease and monensin toxicosis.

Topics: Animals; Body Weight; Enzymes; Female; Kidney; Liver; Male; Minerals; Monensin; Selenium; Statistics as Topic; Swine; Vitamin E

Antibiotic residue has become an emerging environmental contaminant, while the toxicological effects and underlying mechanisms caused by the co-exposure to multiple veterinary antibiotics were rarely studied. In this study, male Sprague Dawley rats were exposed to monensin (M) (1, 2, 10 mg/(kg·body weight (BW)) combined with sulfamethazine (S) (60, 120, 600 mg/(kg·BW)) or single drugs for 28 consecutive days. The body weight, hematological and blood biochemical parameters, organ coefficients, and histopathology were analyzed to discover their combined toxicity effect. Transcriptomic analysis was used to reveal the possible mechanisms of their joint toxicity. Compared with the control group, the weight gain rate was significantly reduced in the H-M+S and H-S, and alkaline phosphatase in H-M+S was significantly increased. Furthermore, relative liver and kidneys weight was significantly increased, and the liver of H-M+S showed more severe lesions in histopathological analysis. For H-M+S, H-M and H-S, transcriptomic results showed that 344, 246, and 99 genes were differentially expressed, respectively. The Gene Ontology terms mainly differ in sterol biosynthetic process and steroid hydroxylase activity. The Kyoto Encyclopedia of Genes and Genome pathways showed abnormal retinol metabolism, metabolism of xenobiotics by cytochrome P450, and drug metabolism-cytochrome 450; the common 30 genes were screened from the network of protein-protein interaction. The results showed that mixed contamination of M and S produces hepatotoxicity by interfering with linoleic acid metabolism, retinol metabolism and CYP450 enzyme-dominated drug metabolism. Further analysis showed that Cyp1a2, Cyp2c61, Ugt1a3, and Ugt1a5 might be the key genes. These findings could provide more evidence for investigating the toxic effects and metabolism of mixed antibiotics contamination in mammals.

Topics: Alkaline Phosphatase; Animals; Anti-Bacterial Agents; Body Weight; Cytochrome P-450 CYP1A2; Cytochrome P-450 Enzyme System; Linoleic Acid; Liver; Male; Mammals; Monensin; Rats; Rats, Sprague-Dawley; Steroid Hydroxylases; Sterols; Sulfamethazine; Transcriptome; Vitamin A; Xenobiotics

Our previous work indicated that feeding oregano essential oil (OEO) in combination with monensin (MON) may not be mutually beneficial to dairy calf growth performance. To evaluate this observation further, a 240-d long-term growth experiment was conducted using 12 young growing Holstein bulls using a 2 × 2 factorial treatment arrangement. Main factors were OEO and MON arranged in 4 individual treatments: (1) ration fed without OEO or MON (control), (2) OEO fed at 26 mg/kg of dry matter (DM), (3) MON fed at 25 mg/kg of DM, and (4) OEO and MON fed in combination (OEO+MON). Holstein bulls were 70 d of age and similar in body weight (BW; 93.3 ± 4.54 kg) and individually fed for 240 d. The targeted feeding rates of OEO and MON were blended into 200 g of concentrate and top dressed each morning to a corn stalklage-based ration. Body weights, frame measurements, and blood samples were collected monthly. Interactions of OEO by MON were detected for BW, BW gain, average daily gain, and a trend for feed conversion. Bulls fed OEO or MON demonstrated greater final BW (368, 385, 381, and 358 kg for control, OEO, MON, and OEO+MON, respectively), and BW gains (278, 292, 285, and 265 kg) and average daily gain (1.16, 1.22, 1.19, 1.11 kg/d) were greatest for bulls fed OEO or MON compared with bulls fed OEO+MON; bulls fed the control were intermediate and similar to bulls fed MON. Intake of DM was greater for bulls fed OEO (6.55, 6.99, 6.60, and 6.42 kg/d) compared with bulls fed remaining treatments. Frame growth gain measurements for heart girth, abdominal girth, withers height, body length, and cannon bone circumference were similar for bulls fed all treatments. Serum triglyceride (0.23, 0.25, 0.28, and 0.24 mmol/L) concentrations were greater for bulls fed MON compared with bulls fed the control and OEO+MON, and bulls fed OEO were intermediate and similar. Cholesterol (2.06, 2.29, 2.20, and 2.07 mmol/L) concentrations were greater for bulls fed OEO compared with bulls fed the control and OEO+MON, and bulls fed MON were intermediate and similar. Serum antioxidant measurements were similar for bulls fed all treatments. Serum IgA, IgG, and IgM concentrations were similar for bulls fed all treatments. Feeding OEO or MON separately can improve growth performance of growing Holstein bulls. We do not know why the combination of OEO and MON is antagonistic to growth performance of Holstein bulls. However, these technologies should not be fed in combination to growing dairy ca

Topics: Animal Feed; Animals; Body Weight; Cattle; Diet; Dietary Supplements; Growth; Male; Monensin; Oils, Volatile; Origanum

The objective of this study was to evaluate growth and performance of postweaning heifers supplemented with monensin (MON), sodium butyrate (SB), or the combination of MON and SB (MSB) compared with heifers not receiving these feed additives. Forty Holstein heifers [mean age 84.2 ± 1.2 d; body weight (BW) 99.8 ± 10.8 kg (mean ± SD)] were housed in a freestall barn, blocked by birth date, and randomly assigned to 1 of 4 treatments in a randomized complete block design. Treatments were (1) 100 g of soybean meal carrier (control; CON); (2) 0.75 g of SB/kg of BW + carrier (SB); (3) 1 mg of MON/kg of BW + carrier (MON); (4) 1 mg of MON/kg of BW + 0.75 g of SB/kg of BW (MSB). Data were analyzed using single degree of freedom contrasts evaluating CON versus additives (ADD), SB versus MON, and SB and MON versus MSB. Treatments were hand-mixed daily. Feed and orts were measured daily and frozen at -20°C. Orts samples were subsampled for dry matter (DM) determination, and total mixed ration samples were taken weekly and composited monthly for DM and nutrient analysis. Initial BW, heart and paunch girths, body length, blood samples, and fecal coccidia counts were measured before the start and weekly during the 12-wk trial. Blood samples were analyzed for glucose, plasma urea nitrogen (PUN), and ketone concentrations. Apparent total-tract nutrient digestibility was determined from d 21 to 27 and from d 63 to 69 using acid detergent insoluble ash as a marker. Daily dry matter intake (DMI) and metabolizable energy intake were increased in ADD compared with CON, and average BW, final BW, and heart girth tended to increase. Whereas MSB tended to be greater than SB and MON for heart girth, feed efficiency was greater with MON compared with SB. Compared with CON, ADD decreased coccidia counts. No effect of treatment on PUN was detected. Monensin and SB tended to have greater plasma glucose than MSB did. Average blood ketone concentrations were greater with ADD versus CON, in SB versus MON, and in MSB versus SB and MON. During the wk-3 digestibility phase, DMI tended to be greater in heifers fed SB versus MON, as well as in heifers fed MSB versus SB and MON. Digestibility of nutrients were similar, except that starch digestibility was increased in heifers fed MSB versus SB and MON. During the wk-9 digestibility phase, DMI and digestibility of nutrients were similar, except NDF, which tended to be greater in CON than in ADD. Overall, ADD resulted in positive growth and reduc

Topics: Animal Feed; Animals; Body Composition; Body Weight; Butyric Acid; Cattle; Cattle Diseases; Diet; Dietary Supplements; Digestion; Energy Intake; Female; Gastrointestinal Tract; Health Status; Monensin; Nutrients; Rumen

Calcium salts of long-chain fatty acids (CSFA) from linseed oil have the potential to reduce methane (CH4) production from ruminants; however, there is little information on the effect of supplementary CSFA on rumen microbiome as well as CH4 production. The aim of the present study was to evaluate the effects of supplementary CSFA on ruminal fermentation, digestibility, CH4 production, and rumen microbiome in vitro. We compared five treatments: three CSFA concentrations-0% (CON), 2.25% (FAL) and 4.50% (FAH) on a dry matter (DM) basis-15 mM of fumarate (FUM), and 20 mg/kg DM of monensin (MON). The results showed that the proportions of propionate in FAL, FAH, FUM, and MON were increased, compared with CON (P < 0.05). Although DM and neutral detergent fiber expressed exclusive of residual ash (NDFom) digestibility decreased in FAL and FAH compared to those in CON (P < 0.05), DM digestibility-adjusted CH4 production in FAL and FAH was reduced by 38.2% and 63.0%, respectively, compared with that in CON (P < 0.05). The genera Ruminobacter, Succinivibrio, Succiniclasticum, Streptococcus, Selenomonas.1, and Megasphaera, which are related to propionate production, were increased (P < 0.05), while Methanobrevibacter and protozoa counts, which are associated with CH4 production, were decreased in FAH, compared with CON (P < 0.05). The results suggested that the inclusion of CSFA significantly changed the rumen microbiome, leading to the acceleration of propionate production and the reduction of CH4 production. In conclusion, although further in vivo study is needed to evaluate the reduction effect on rumen CH4 production, CSFA may be a promising candidate for reduction of CH4 emission from ruminants.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Body Weight; Calcium; Cluster Analysis; Detergents; Digestion; DNA, Bacterial; Fatty Acids; Fermentation; Fumarates; Gases; In Vitro Techniques; Linseed Oil; Megasphaera; Methane; Microbiota; Monensin; RNA, Ribosomal, 16S; Rumen; Salts; Selenomonas; Sheep; Silage; Streptococcus

The objectives of this study were to assess the effects of Saccharomyces cerevisiae fermentation products (SCFP; NaturSafe, SCFPns; and Original XPC, XPC; Diamond V) on growth performance, carcass traits, immune response, and antimicrobial resistance in beef steers fed high-grain diets. Ninety Angus steers (initial body weight [BW], 533 ± 9.8 kg) were assigned to a randomized complete design with 6 treatments (n = 15/treatment): 1) control, 2) low (12 g SCFPns·steer-1·d-1), 3) medium (15 g SCFPns·steer-1·d-1), 4) high SCFP (18 g SCFPns·steer-1·d-1), 5) encapsulated XPC (eXPC; 7 g XPC·steer-1·d-1 encapsulated with 9 g capsule material), and 6) antibiotics (ANT; 330 mg monensin + 110 mg tylosin·steer-1·d-1). Steers were fed ad libitum a diet containing 10% barley silage and 90% barley grain concentrate mix (dry matter basis) for 105 d. Increasing SCFPns tended (P < 0.09) to linearly increase feed efficiency. Average daily gain (ADG) tended (P < 0.10) to be greater in steers supplemented with eXPC than control. The SCFPns also tended (P < 0.10) to linearly increase marbling score. Proportion of severely abscessed livers tended (P < 0.10) to be lower in steers supplemented with medium and high SCFPns, eXPC, or ANT. A treatment × days on feed interaction were noticed (P < 0.01) for blood glucose, blood urea nitrogen (BUN), and acute phase proteins. The concentration of blood glucose responded quadratically (P < 0.05) on days 28 and 56, whereas BUN linearly (P < 0.01) increased on day 105 with increasing SCFPns dose. The SCFPns linearly increased haptoglobin (P < 0.03) and serum amyloid A (SAA;P < 0.05) concentrations on day 105, and lipopolysaccharide binding protein (LBP;P < 0.01) on days 56 and 105. The percentage of erythromycin-resistant and erythromycin + tetracycline-resistant enterococci was greater (P < 0.05) with ANT than control, SCFPns, and eXPC, whereas no difference was observed among control, SCFPns, and eXPC. No treatment effect was detected on the percentage of tetracycline-resistant enterococci. These results indicate that feeding SCFPns and eXPC was beneficial in improving ADG, feed efficiency and decreasing liver abscesses in a manner comparable to ANT. Unlike antibiotics, SCFPns or eXPC did not increase antimicrobial resistance. Both SCFPns and eXPC are potential alternatives to in-feed antibiotics.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Blood Urea Nitrogen; Body Weight; Cattle; Diet; Dietary Supplements; Drug Resistance, Bacterial; Enterococcus; Fermentation; Hordeum; Male; Monensin; Random Allocation; Saccharomyces cerevisiae; Silage; Tylosin

The aim was to evaluate the effect of different feed additives on intake, performance, and fecal consistency index (FCI) of dairy calves from 6-60 d of age and its residual effect 15 d after weaning. Fifty Holstein calves (38 ± 1.0 kg BW) were fed 5 L/d of milk plus starter feed until weaning, and corn silage and concentrate after weaning. The treatments were: control (CON), monensin (MON; 30 mg/kg of starter), probiotic E. faecium (PROB; 70 mg/kg of starter), essential oils (EO; 300 mg/kg of starter), or PROB + EO (EOPROB). Fecal score and dry matter intake (DMI) were measured daily, and animals were weighed every 15 d. A DNA extraction from feces was performed to identify the presence of microorganisms (E. coli, Hafnia, Shiguella, Lactobacillus spp, Enterococcus spp, and Enterococcus faecium NCIMB 10415) by PCR. Two 72-h digestibility trials were performed at days 20-28 and 50-56, by total fecal collection. The DMI before weaning was greater for EO (903.0 g/d) compared with MON (794.3 g/d) and EOPROB (783.1 g/d). The FCI decreased during pre-weaning for EO and MON. Average daily gain (ADG) and feed efficiency (FE) did not differ among treatments before weaning. After weaning, DMI and FCI did not differ among treatments. The EO had greater ADG (917.5 g/d) compared with CON (615.8 g/d) and PROB (592.6 g/d). The FE improved with EO (0.72 g/g) over CON (0.36 g/g), MON (0.49 g/g), and PROB (0.36 g/g). The PCR results showed absence of E. faecium NCIMB 10415 in animals fed PROB and CON. Animals fed PROB had greater intake of CP and NDF than animals fed EOPROB. The EO can be added to the dairy calf ration to improve fecal score and increase DMI. The pre-weaning FCI decrease with MON and increase with PROB.

Topics: Animal Feed; Animals; Body Weight; Cattle; Diet; Dietary Supplements; Eating; Female; Growth; Male; Milk; Monensin; Probiotics; Rumen; Silage; Weaning; Zea mays

The aim of this study was to test whether a combination of plant bioactive lipid compounds (also termed 'essential oils') and biotin (PBLC+B) could decrease the mobilization of body reserves and ketosis incidence in postpartum dairy cows. We compared non-supplemented control (CON) cows with cows receiving monensin (MON) as a controlled-release capsule at d -21, and with cows receiving PBLC+B from day (d) -21 before calving until calving (Phase 1) and further until d 37 after calving (Phase 2), followed by PBLC+B discontinuation from d 38 to d 58 (Phase 3). The PBLC+B cows had higher body weight and higher back fat thickness than CON cows and lesser body weight change than MON and CON cows in Phase 3. Body condition score was not different among groups. Milk protein concentration tended to be higher on the first herd test day in PBLC+B vs. CON cows. Milk fat concentration tended to be highest in PBLC+B cows throughout Phases 2 and 3, with significantly higher values in PBLC+B vs. MON cows on the second herd test day. Yields of energy-corrected milk were higher in PBLC+B vs. CON and MON cows in Phase 2 and higher in PBLC+B and MON cows vs. CON cows in Phase 3. The incidence of subclinical ketosis was 83%, 61% and 50% in CON, PBLC+B and MON cows, respectively, with lower mean β-hydroxybutyrate values in MON than in PBLC+B cows in Phase 1 prepartum. The serum triglyceride concentration was higher in PBLC+B vs. CON cows on d 37. No differences were observed in serum glucose, urea, non-esterified fatty acids, cholesterol and bilirubin concentrations. Aspartate transaminase and γ-glutamyltranspeptidase but not glutamate dehydrogenase activities tended to be highest in MON and lowest in PBLC+B in Phase 2. We conclude that PBLC+B prevent body weight loss after parturition and are associated with similar ketosis incidence and partly higher yields of energy-corrected milk compared to MON supplementation of dairy cows.

Topics: Animal Feed; Animals; Biotin; Blood Chemical Analysis; Body Weight; Cattle; Dairying; Drug Interactions; Energy Metabolism; Female; Ketosis; Lactation; Lipids; Milk; Monensin; Plants

The objective of this study was to determine if feeding monensin would improve diet digestion, energy and nitrogen balance in bred heifers receiving a limit-fed corn stalk-based diet. Sixteen pregnant Meat Animal Research Center (MARC) III composite heifers were used in a 161-d completely randomized design. Heifers were randomly assigned to one of two treatments, no monensin (CON) or 150 mg/d monensin (MON), with eight heifers in each treatment group. Heifers were limit-fed a corn stalk-based diet at 100% of MEm requirements. Effects of monensin on energy and nitrogen balance were determined via total fecal and urine collections and open-circuit respiration calorimetry. Total fecal and urine collection occurred on d 14, 42, and 161 of monensin feeding, and calorimetry measurements were made on d 0, 3, 14, 28, 42, and 161 of monensin feeding. DMI was not different (P = 0.94) for CON and MON heifers and, by design, increased (P < 0.01) from d 14 to d 161 of the trial to account for increasing fetal growth requirements. No differences (P = 0.91) in GE intake were observed between CON and MON heifers, and DE and ME intakes did not differ (P > 0.58) with monensin inclusion. DM, OM, NDF, and ADF digestion did not differ (P > 0.52) between treatments. Fecal, methane, urinary, and heat energy losses were not different (P > 0.16) for MON and CON heifers. Methane production was not different between treatments when expressed as daily liters of methane (P = 0.40); however, MON heifers produced 7% less (P = 0.03) methane per day than CON heifers when expressed as liters of methane produced on a metabolic body weight (MBW) basis. Furthermore, monensin had no effect (P = 0.36) on overall retained energy (RE). Nitrogen intake and excretion was not different (P > 0.13) between treatment groups. Results of this experiment indicate that adding monensin to limit-fed, corn stalk-based diets may not have a large effect on the energy and nitrogen balance of confined heifers.

Topics: Animal Feed; Animals; Body Weight; Cattle; Diet; Digestion; Eating; Energy Metabolism; Feces; Female; Methane; Monensin; Nitrogen; Nutrients; Pregnancy; Random Allocation; Zea mays

This study evaluated the effect of increasing levels of monensin sodium (MON) in diets with virginiamycin (VM) on the finishing of feedlot cattle. Two hundred and eighty intact male Nellore cattle (348 ± 32 kg body weight, 22 months) received one of the following five diets: control diet (without additives); diet containing VM (25 mg per kg dry matter) combined with 0 (MON0), 10 (MON10), 20 (MON20) or 30 (MON30) mg MON per kg dry matter. During adaptation (28 days), the MON0 diet increased dietary net energy for maintenance and gain compared to the control diet (P = 0.04). The combination of additives linearly reduced dry matter intake, body weight and average daily gain (P < 0.01). Considering the total study period (110 days), there was a trend of greater net energy intake for maintenance (P = 0.09) and hot carcass weight (P = 0.06) for animals fed MON0 compared to the control diet. The combination of additives linearly reduced dry matter intake (P = 0.04) and linearly increased gain : feed and dietary net energy for maintenance and gain (P < 0.01). The combination of VM with MON at a dose of 30 mg/kg dry matter is recommended for Nellore feedlot cattle because it improves the efficiency of energy utilization.

Topics: Animals; Body Weight; Cattle; Diet; Dose-Response Relationship, Drug; Eating; Energy Intake; Energy Metabolism; Male; Monensin; Virginiamycin; Weight Gain

We developed a flow-limited physiologically based pharmacokinetic model for residues of monensin in chickens and evaluated its predictive ability by comparing it with an external data set describing concentration decays after the end of treatment. One advantage of this model is that the values for most parameters (34 of 38) were taken directly from the literature or from field data (for growth and feed intake). Our model included growth (changes in body weight) to describe exposure throughout the life of the chicken. We carried out a local sensitivity analysis to evaluate the relative importance of model parameters on model outputs and revealed the predominant influence of 19 parameters (including three estimated ones): seven pharmacokinetic parameters, five physiological parameters and seven animal performance parameters. Our model estimated the relative bioavailability of monensin as feed additive at 3.9%, which is even lower than the absolute bioavailability in solution (29.91%). Our model can be used for extrapolations of farming conditions, such as monensin supplementation or building lighting programme (which may have a significant impact for short half-life molecules such as monensin). This validated PBPK model may also be useful for interspecies extrapolations or withdrawal period calculations for modified dosage regimens.

Topics: Animal Feed; Animals; Biological Availability; Body Weight; Chickens; Half-Life; Monensin

Two hundred fifty-two cross-bred yearling steers (406 ± 24 kg BW) were used in a completely randomized block design with a 2 × 2 factorial arrangement of treatments (7 pens/treatment) to evaluate the effects of dietary Saccharomyces cerevisiae fermentation product (SFP) and monensin (MON) on growth performance and carcass characteristics. Dietary treatments arranged as a 2 × 2 factorial were 1) with or without SFP and 2) with or without MON. Finishing diets contained 19.7% of DM as dried distiller's grains with solubles. Both SFP and MON were added in the total mixed ration in place of an equal amount of cornmeal (DM basis; target intake = 2.8 g of SFP and 33 mg of MON/kg of dietary DM). Each treatment group was offered ad libitum access to a transition ration from d 1 to 8 and then to the finishing ration from d 9 to 125. Body weights were collected on d 0, 28, 56, 84, 110, and 125. Initial and final BW was an average of 2-d weights (d -1 and 0 and d 124 and 125, respectively). Steers were shipped for harvest on d 125. Overall ADG was decreased (P = 0.03) in steers supplemented with SFP, but final BW was similar among treatments. Feeding SFP was associated with lighter (P < 0.01) HCW and a greater (P = 0.01) number of carcasses grading USDA Choice. Twelfth rib fat thickness was not affected by SFP (P = 0.82) or MON (P = 0.35), but numerical decreases in 12th rib fat thickness among cattle receiving SFP or MON alone contributed to a tendency (P = 0.07) for greater 12 rib fat thickness when SFP and MON were provided. There was no effect of treatment on cost of gain (P ≥ 0.21). The effects of SFP in the current study may have been limited in heavy yearling steers due to consumption of a finishing diet containing 19.7% dried distiller's grains with solubles.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Body Composition; Body Weight; Cattle; Diet; Edible Grain; Fermentation; Monensin; Saccharomyces cerevisiae

The effects of monensin on transition cow metabolism may be dependent on modulation of feeding behavior, rumen pH, and expression of key metabolic genes. Multiparous Holstein cows were used to determine the effects of monensin (400mg/cow daily) on these variables. Cows were randomly assigned, based on calving date, to control or monensin treatments (n = 16 per treatment) 21 d before their expected calving date, and cows remained on treatments through 21 d postpartum. Feeding behavior and water intake data were collected daily. Liver biopsies were conducted after assessing BCS and BW on d -21, -7, 1, 7, and 21 relative to calving for analysis of triglyceride (TG) content as well as mRNA abundance of cytosolic phosphoenolpyruvate carboxykinase, carnitine palmitoyltransferase 1a, and apolipoprotein B. Blood samples were collected 21, 7, and 4 d before expected calving and 1 (day of calving), 4, 7, 14, and 21 d postpartum for nonesterified fatty acid, β-hydroxybutyrate, glucose, insulin, and haptoglobin analyses. Ruminal pH was collected every 5 min on d 1 through 6 postpartum via a wireless indwelling probe. On d 7 postpartum, a caffeine clearance test was performed to assess liver function. Data were analyzed using mixed models with repeated measures over time. Monensin decreased mean plasma β-hydroxybutyrate (734 vs. 616 ± 41 μM) and peak concentrations (1,076 vs. 777 ± 70 μM on d 4 postpartum). Monensin also decreased time between meals prepartum (143 vs. 126 ± 5.0 min) and postpartum (88.8 vs. 81.4 ± 2.9 min), which was likely related to a smaller ruminal pH standard deviation in the first day after cows changed to a lactation ration (0.31 vs. 0.26 ± 0.015). Monensin also increased liver mRNA abundance of carnitine palmitoyltransferase 1a (0.10 vs. 0.15 ± 0.002 arbitrary units), which corresponded to a slower rate of liver TG accumulation from d -7 to +7 (412 vs. 128 ± 83 mg of TG/g of protein over this time period). No significant effects of monensin supplementation were observed on milk production, liver cytosolic phosphoenolpyruvate carboxykinase, apolipoprotein B, plasma nonesterified fatty acid, glucose, insulin, or haptoglobin. No effects on disease incidence were detected, but sample size was small for detecting such effects. Overall, results confirm that the effects of monensin on transition cows extend beyond altered propionate flux.

Topics: Animals; Antiprotozoal Agents; Body Weight; Caffeine; Cattle; Diet; Drinking; Eating; Fatty Acids, Nonesterified; Feeding Behavior; Female; Haptoglobins; Hydrogen-Ion Concentration; Lactation; Liver; Monensin; Postpartum Period; Pregnancy; Rumen

Twenty midlactation Holstein cows (4 ruminally fistulated) averaging 101 +/- 34 d in milk and weighing 674 +/- 77 kg were used to compare rations with brown midrib corn silage (bm3) to rations with dual-purpose control silage (DP) on N utilization and milk production. The effect of monensin in these rations was also examined. Animals were assigned to one of five 4 x 4 Latin squares with treatments arranged in a 2 x 2 factorial. Cows were fed 1 of 4 treatments during each of the four 28-d periods. Treatments were 1) 0 mg/d monensin and bm3 corn silage, 2) 0 mg/d monensin and DP corn silage, 3) 300 mg/d monensin and bm3 corn silage, and 4) 300 mg/d monensin and DP corn silage. In vitro 30-h neutral detergent fiber (NDF) digestibility was greater for bm3 corn silage (61.0 vs. 49.1 +/- 0.62). Dry matter intake (DMI) tended to be greater for cows consuming bm3 corn silage (21.3 vs. 20.2 kg/d). Neither hybrid nor monensin affected milk production, fat, or protein (37.7 kg, 3.60%, or 3.04%). Monensin tended to increase rumen pH (5.89 vs. 5.79 +/- 0.07) compared with the control treatment. In addition, bm3 corn silage resulted in a significant decrease in rumen pH (5.72 vs. 5.98 +/- 0.07). Supplementing monensin had no effect on molar proportions of acetate, propionate, or butyrate. In contrast, an increase was observed in branched-chain volatile fatty acids. No treatment interactions were observed for rumen pH or molar proportion of propionate but monensin decreased the molar proportion of acetate and increased the molar proportion of butyrate when cattle consumed bm3 silage. Dry matter, N, and acid detergent fiber digestibility were lower for the bm3 ration, whereas NDF digestibility was not different between treatments. There was no effect of hybrid on microbial protein synthesis (1,140 g/d) as estimated by urinary concentration of purine derivatives. Cows consuming bm3 excreted more fecal N than cows consuming DP (38.2 vs. 34.4% N intake); however, based on spot sampling, estimated urinary and manure N were not different between treatments (35.8 and 71.9% N intake). Monensin had no effect on DMI, digestibility of any nutrients, or N metabolism, and there were no hybrid by monensin interactions. Rations including bm3 corn silage tended to increase DMI but did not affect production. The reduction in the digestibility of some nutrients when cows consumed bm3 may have been caused by increased DMI and possible increased digestion in the lower gut. This increase in

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Body Weight; Cattle; Feces; Female; Ionophores; Kinetics; Lactation; Male; Milk; Monensin; Nitrogen; Random Allocation; Rumen; Silage; Zea mays

We examined the effects of monensin, provided by controlled-release capsules, on the enteric methane emissions and milk production of dairy cows receiving ryegrass pasture and grain. In a grazing experiment, 60 Holstein-Friesian cows were assigned randomly to 1 of 2 groups (control or monensin). Cows in the monensin group received 2 controlled-release capsules, with the second capsule administered 130 d after the first. Milk production was measured for 100 d following insertion of each capsule. The sulfur hexafluoride tracer gas technique was used to measure enteric methane emissions for 4 d starting on d 25 and 81 after insertion of the first capsule, and on d 83 after insertion of the second capsule. All cows grazed together as a single herd on a predominantly ryegrass sward and received 5 kg/d of grain (as-fed basis). In a second experiment, 7 pairs of lactating dairy cows (control and monensin) were used to determine the effects of monensin controlled-release capsules on methane emissions and dry matter intake. Methane emissions were measured on d 75 after capsule insertion by placing cows in respiration chambers for 3 d. Cows received fresh ryegrass pasture harvested daily and 5 kg/d of grain. The release rate of monensin from the capsules used in both experiments was 240 +/- 0.072 mg/d, determined over a 100-d period in ruminally cannulated cows. The monensin dose was calculated to be 12 to 14.5 mg/kg of dry matter intake. There was no effect of monensin on methane production in either the grazing experiment (g/d, g/kg of milk solids) or the chamber experiment (g/d, g/kg of dry matter intake). In the grazing study, there was no effect of monensin on milk yield, but monensin increased milk fat yield by 51.5 g/d and tended to increase milk protein yield by 18.5 g/d. Monensin controlled-release capsules improved the efficiency of milk production of grazing dairy cows by increasing the yield of milk solids. However, a higher dose rate of monensin may be needed to reduce methane emissions from cows grazing pasture.

Topics: Animals; Body Weight; Cattle; Delayed-Action Preparations; Diet; Edible Grain; Female; Intestinal Mucosa; Intestines; Lactation; Lolium; Methane; Monensin

Three hundred seventy-one crossbred-yearling heifers (299 +/- 9 kg initial BW) were obtained from a common source and used in a randomized complete-block designed finishing study. A 2 x 3 factorial arrangement of treatments was used with one factor being diet: based on steam-flaked corn finishing diet (SFC) or SFC plus 25% (dry basis) corn wet distillers grains with solubles (WDGS). The second factor was feed additives: no added antibiotics (NONE), 300 mg of monensin daily (MONENSIN), or 300 mg of monensin + 90 mg of tylosin daily (MON+TYL). Main effect of diet resulted in no difference in DMI (P = 0.34). Heifers fed SFC gained 9% faster (P = 0.01) and were 7% more efficient (P = 0.01) than heifers fed WDGS. In addition, heifers fed SFC had 3% heavier (P = 0.01) HCW; 1% greater (P = 0.01) dress yield; and had 3% larger (P = 0.05) LM area. Marbling score and carcasses that graded USDA Choice or better were both greater (P /= 0.12) among feed additive treatments. Kidney, pelvic, and heart fat and s.c. fat thickness at the 12th rib were also not different (P >/= 0.55) for main effects of diet and feed additive. There was a tendency (P = 0.09) for a diet x feed additive interaction for the most severe (A+) liver abscesses. Heifers fed NONE yielded the greatest percentage (16%) of A+ livers in the SFC treatment, whereas heifers fed MON+TYL yielded the greatest percentage (10%) in the WDGS treatment. Including wet distillers grains with solubles in diets based on steam-flaked corn decreased finishing heifer performance, HCW, and marbling. Tylosin addition tended to decrease severity of liver abscesses in diets containing SFC, but not in diets containing WDGS. These data indicate that monensin and tylosin may not be as effective when used in steam-flaked corn diets with 25% WDGS.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Anti-Bacterial Agents; Body Weight; Cattle; Female; Meat; Monensin; Random Allocation; Tylosin; Zea mays

Effects of prepartum administration of a monensin controlled release capsule (CRC) on rumen pH, dry matter intake, and milk production during the transition period and early lactation were determined in 16 multiparous Holstein cows. Cows were divided into blocks of 2 depending on calving date. Cows were fed either a close-up dry cow or a lactating cow total mixed ration ad libitum. Rumen pH was monitored continuously using indwelling probes. Monensin did not affect average daily rumen pH, time below pH 6, time below pH 5.6, area below pH 6, and area below pH 5.6 throughout the experiment. Average daily pH, time below pH 6, and time below pH 5.6 before calving were 6.62, 65.6 min/d, and 17.6 min/d, respectively, and did not differ among the weeks before calving. Average daily pH, time below pH 6, and time below pH 5.6 were 6.19, 443.3 min/d, and 115.5 min/d, respectively, during the first week after calving, and were 6.36, 204.3 min/d, and 52.4 min/d, respectively, during the sixth week after calving. In the weeks after calving, average daily pH showed a quadratic increase, time below pH 6 showed a quadratic decrease, and time below pH 5.6 showed a linear decrease. Monensin did not affect dry matter intake and daily yields of milk, milk fat, and milk protein. Results suggest that prepartum administration of a monensin CRC did not increase rumen pH in multiparous cows fed the experimental diets during the transition period and early lactation.

Topics: Animals; Body Composition; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Eating; Female; Hydrogen-Ion Concentration; Ketosis; Lactation; Milk; Monensin; Parturition; Pregnancy; Rumen

Coccidiosis, caused by Eimeria species, is a serious economic disease of chickens (Gallus gallus) and the search for vaccines to control the disease is intensifying especially with the increasing threat of drug resistance. A live attenuated multi-valent ionophore-tolerant Eimeria vaccine has been developed that contains three ionophore-resistant Eimeria species, E. tenella, E. maxima and E. acervulina. The attenuated lines were derived from virulent field strains resistant to monensin ionophore by selection for early development in chicks. The vaccine was administered by gavage and through drinking water to broiler chickens, Chinese Yellow strain, reared in wire cages. Vaccinated medicated birds performed better than vaccinated unmedicated and medicated unvaccinated groups. The final mean weights of vaccinated medicated birds were significantly higher (P<0.05), and a better vaccine protection index, using both vaccinating methods, was achieved. Results indicated that concomitant use of ionophores and vaccines could be a useful adjunct to planned immunization in the control of coccidiosis.

Topics: Administration, Oral; Animals; Body Weight; Chickens; Coccidiosis; Eimeria; Feces; Female; Ionophores; Male; Monensin; Parasite Egg Count; Poultry Diseases; Protozoan Vaccines; Vaccination; Vaccines, Attenuated

This study aimed to validate a previously developed model for the estimation of energy balance in high producing dairy cows from test day information during the first 12 wk of lactation. Monensin (an ionophor) increases the energy status of dairy cows. Gold standard for the validation was a higher energy status, indicated by lower blood ketone body concentrations, lower percent milk fat, and higher milk-yield of monensin-supplemented than control cows in 8 randomized block design feeding trials. Estimated energy intake (eE(intake)) was calculated as estimated energy balance (eEB) plus energy in actual milk produced (in units of MJ(nel)) plus a constant or variable amount of energy required for maintenance. The variable amount was based on BW, while the constant was the average BW in each parity group (1, 2, 3, 4+). Both eEB and eE(intake) were compared between groups of cows with and without monensin supplementation (n = 600 lactations). The trials started with a presupplement period during lactation wk 2 to 5 followed by a supplementation period during lactation wk 6 to 12. During the presupplement period, both eEB and eE(intake) were similar for all cows. At 2, 3, and 8 wk after starting the monensin supplementation, the eEB of the supplemented cows was significantly higher, while eE(intake) was significantly higher throughout the supplementation period. The results were similar for the 2 methods of calculating energy for maintenance, variable or constant. The feed conversion efficiency, calculated as kg of fat-protein corrected milk per MJ(nel) of eE(intake), was highest in first calving cows compared with cows having more lactations, and correlated with standard milk production at trial group level. It was concluded that eE(intake) was a valid measure of net energy absorption.

Topics: Animal Nutritional Physiological Phenomena; Animals; Blood Proteins; Body Weight; Cattle; Energy Intake; Energy Metabolism; Female; Ketone Bodies; Lactation; Lipids; Milk; Monensin

We investigated the effect of high (12, 20, and 50 mM) extracellular K+ concentrations ([K+]0) on [U-14C] acetate oxidation to CO2 in cerebral cortex slices of control and perinatal malnourished rats. High [K+]o increased the acetate oxidation, compared with a medium containing 2.7 mM [K+]0. By investigating the mechanisms involved in this stimulation, it was shown that (i) ouabain (1 mM) and monensin (10 microM) prevented this increase; (ii) in a medium with physiological [K+]0 (2.7 mM), the decreasing of [Na+]0 stimulated acetate oxidation. These results suggest that the stimulatory effect of [K+]0 on acetate oxidation was due to the decreasing of Na1 levels. Considering that malnutrition could alter the activity of Na+,K(+)-ATPase and/or other pertinent proteins, its effect on acetate oxidation was investigated. The malnutrition, which altered the body and cerebral weight of rats, did not modify the acetate oxidation in any protocol.

Topics: Acetates; Animals; Body Weight; Brain; Cerebral Cortex; Female; Malnutrition; Monensin; Ouabain; Oxidation-Reduction; Potassium; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Wistar; Reference Values

The effects of diclazuril and monensin, when included in the feed of turkeys from 0 to 10 wk, upon performance and development of immunity to Eimeria species was investigated. Birds were initially inoculated with a low dose of oocysts of three species of Eimeria at 3, 5, 7, and 9 days of age in order to simulate a natural infection. Weight gain and feed intake from 0 to 6 wk of age was significantly greater in medicated birds compared with those that received no anticoccidial medication. Weight gain and feed intake from 6 to 10 wk was greater in birds that received diclazuril than in unmedicated birds. No differences in performance were evident after drug withdrawal from 10 to 16 wk. Immunity to Eimeria species developed by 10 wk in birds that received no anticoccidial medication but did not develop in those given diclazuril or monensin.

Topics: Animal Feed; Animals; Body Weight; Coccidiosis; Coccidiostats; Eating; Eimeria; Immunity, Innate; Monensin; Nitriles; Poultry Diseases; Triazines; Turkeys

Fifty-five multiparous Holstein dairy cows were used to evaluate the singular and combined effects of somatotropin and monensin treatments during the late dry period on postpartum metabolism and production. Treatments were 1) control (C); 2) injection of exogenous bovine somatotropin (bST); 3) TMR top dressed with 300 mg of monensin/day (M); and 4) monensin and somatotropin in combination (bST+M) during the last 28 days before expected parturition. A 500-mg subcutaneous injection of sustained release somatotropin was administered adjacent to the tail head at d -28 and -14 relative to expected calving. Diet and management were the same for all cows after parturition. Production and intake were measured daily until 63 d in milk. Milk composition, blood metabolites, and body weight and condition score were measured weekly. Prepartum glucose, nonesterified fatty acid, and blood urea nitrogen concentrations were not different among treatments. Cows on the M treatment tended to have greater dry matter intake postpartum than those on the C treatment and 30% lower plasma nonesterified fatty acid concentrations during wk 1 postpartum than all other treatments. Milk yield and milk fat yield were not different among treatments, but milk fat percent tended to be lower for the bST+M treatment than the C treatment. Changes in plasma amino acid concentrations were consistent with mobilization of skeletal muscle protein, possibly for use in gluconeogenesis. Results from this study provide evidence that prepartum feeding of monensin reduced plasma nonesterified fatty acid concentrations and may improve glucose metabolism of the periparturient dairy cow.

Topics: Animals; Blood Glucose; Blood Urea Nitrogen; Body Weight; Cattle; Eating; Energy Metabolism; Fatty Acids; Female; Growth Hormone; Ionophores; Lactation; Milk; Monensin; Pregnancy; Time Factors

We examined the effects of monensin on feed intake and milk production in Holstein-Friesian cows receiving a total mixed rations in two experiments. In experiment 1, 60 individually fed cows consumed, during wk 7 to 26 of lactation, 1 kg/d of supplement containing either 0, 150,300, or 450 mg of monensin. In experiment 2, 98 group-fed cows also received 1 kg/d of a supplement with either 0 or 300 mg/d of monensin for two consecutive lactations. In lactations 1 and 2, treatment started at wk 8 and 3 wk prior to calving, and continued for 32 wk. In experiment 1, 150, 300, and 450 mg of monensin/d produced a small decrease in feed intake and milk yield responses of 2.8, 2.5 and 1.5 kg/d, respectively. In experiment 2, milk yield responses of 0.8 and 1.1 kg/d were recorded in lactations 1 and 2. Milk fat and milk protein content declined in experiments 1 and 2, lactations 1 and 2 by 0.46, 0.38 and 0.27%, and 0.16, 0.16 and 0.11%, respectively. Yield of milk constituents was unaffected. Efficiency of milk production was increased by 5% in experiment 1. In experiment 2, lactation 2, monensin decreased beta-hydroxybutyrate and acetoacetate but increased blood glucose concentration.

Topics: 3-Hydroxybutyric Acid; Acetoacetates; Animals; Blood Glucose; Body Weight; Cattle; Energy Intake; Fats; Female; Ionophores; Lactation; Milk; Milk Proteins; Monensin; Time Factors

Studies were carried out to investigate the effects of monensin and tiamulin, and the simultaneous administration of both compounds on microsomal enzymes in rats. In Phase I of the experiments the effects of monensin and tiamulin were studied separately (monensin 10, 30, and 50 mg/kg or tiamulin 40, 120, and 200 mg/kg body weight, respectively), while in Phase II the two compounds were administered simultaneously (monesin 10 mg/kg and tiamulin 40 mg/kg b.w., respectively). When monensin was administered by itself, it exerted no significant effect on microsomal liver enzymes. In a few cases, slight inhibition of certain enzyme activities was seen. Tiamulin provoked a dose-dependent hepatic enzyme induction. The combined administration of monensin and tiamulin at low doses (10 and 40 mg/kg, respectively) resulted in marked elevation of P450-related enzyme activities. The enzyme induction was more pronounced in females than in males. The results suggest that the simultaneous administration of tiamulin may influence the biotransformation of monensin, possibly increasing the amount of reactive metabolite(s) of the ionophore antibiotic.

Topics: Animals; Anti-Bacterial Agents; Body Weight; Cytochrome P-450 Enzyme System; Diterpenes; Dose-Response Relationship, Drug; Drug Interactions; Enzyme Induction; Female; Ionophores; Male; Microsomes, Liver; Monensin; Organ Size; Rats

As a preliminary in vivo approach in order to study the mechanism of toxicity of the veterinary anticoccidial monensin, male Wistar rats were orally administered 0, 2 and 12 mg kg-1 body wt. day-1 of monensin for 7 days. At the end of the experiment, effects of the ionophore on serum creatine kinase, lactic dehydrogenase and selected drug metabolising enzyme activities were investigated. Furthermore, liver, heart and quadriceps femoris muscle samples were submitted to morphological investigations. Clinical signs or increasing levels of enzymic markers of muscle injury attributable to monensin toxicosis have never been observed in treated animals. As a matter of fact all drug metabolising enzymes activities checked have not shown significant changes, except for a significant decrease of ethoxyresorufin O-deethylase (up to 31%) and aminopyrine N-demethylase (17%) activities. Morphologically, mitochondrial cristae fragmentation and initial formation of 'myelinic sheaths-like' structures have been noticed in heart and muscle fibres. As far as rat study is concerned, these results confirm heart and muscle as target organs of monensin toxicity. In addition, these findings suggest that the inhibition of hepatic biotransformation processes following the i.p. administration of the ionophore, as reported previously by other authors, might reflect unspecific cellular toxic effects rather than a specific enzyme damage.

Topics: Animals; Antiprotozoal Agents; Biotransformation; Body Weight; Creatine Kinase; Cytochrome P-450 Enzyme System; Glutathione; Heart; L-Lactate Dehydrogenase; Liver; Male; Mitochondria; Monensin; Muscle, Skeletal; Organ Size; Pharmaceutical Preparations; Rats; Rats, Wistar

An experiment was designed to examine subclinical ketosis in periparturient dairy cows and the antiketogenic effects of monensin. Subclinical ketosis was induced through a 10% feed restriction and was quantitatively determined using a blood beta-hydroxybutyrate (BHBA) threshold of 1200 mumol/L. Monensin decreased the BHBA concentration by 35% and increased the glucose concentration by 15%. No effect of monensin on milk production was detected, but rumen fermentation was altered. Monensin decreased the acetate to propionate ratio, decreased the butyrate concentration, and increased pH. The lower concentration of BHBA in blood and higher concentration of blood glucose in cows treated with a monensin controlled-release capsule decreased subclinical ketosis in early lactation cows.

Topics: 3-Hydroxybutyric Acid; Ammonia; Animals; Blood Glucose; Body Composition; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Energy Metabolism; Fatty Acids, Volatile; Female; Fermentation; Food Deprivation; Hydrogen-Ion Concentration; Ketosis; Lactation; Monensin; Nitrogen; Rumen; Urea

Roxarsone and monensin are common poultry feed additives that are used alone or in combination with other drugs to improve growth and feed utilization in young birds. The effects of monensin and roxarsone on the physiology of flexoral tendons of broiler chickens were examined to understand their relationships to leg weakness that have been occasionally associated with these drugs. Day-old chickens were fed either roxarsone or monensin for a period of 6 wk with two regimens of each of the drugs (roxarsone, 45.4 or 90.8 g/ton feed; monensin, 100 or 150 g/ton feed). None of the treatments had any adverse effect on the growth of the birds or caused any significant leg problem. Roxarsone at 45.4 g/ton caused a significant gain in body weight. The biomechanical strength of digital flexoral tendons was measured in several ways. There were no statistical differences in load at break, the modulus of elasticity, or stress or strain levels between different treatment groups and birds that received no medication. There were no differences in collagen, proteoglycan, and pyridinoline content of tendons. Sequential extraction of tendons with different solvents revealed a significant increase in the percentage of guanidine HCl extractible collagens in monensin-treated birds, and a decrease in the acid extractible collagen in both roxarsone- and monensin-treated groups. The relative content of collagen in acid extractible collagens were significantly small relative to total collagen content. Majority of collagen (84 to 90%) was extractible with pepsin. About 8 to 11% of total collagen was resistant to pepsin that was extractible with collagenase; this did not differ between treatment groups. Roxarsone treatment had no effect on the guanidine soluble collagen pool. The effect of monensin on the increase in guanidine soluble pool of collagen may relate to its disruptive effects on cellular secretory processes, which may be of significance in modulating connective tissue function in conjunction with other factors. However, in the present study, neither roxarsone nor monensin alone produced any significant leg problems nor caused any significant differences in the physiology of flexoral tendons or altered their biomechanical properties.

Topics: Amino Acids; Animal Feed; Animals; Anti-Bacterial Agents; Biomechanical Phenomena; Body Weight; Chickens; Coccidiostats; Cohort Studies; Collagen; Dose-Response Relationship, Drug; Food Additives; Glycosaminoglycans; Male; Monensin; Roxarsone; Tendons

Four primiparous Holstein cows were gradually introduced, according to a Latin square design, to four diets obtained from the factorial combination of two forage to concentrate ratios (70:30 and 50:50) and two concentrations of monensin sodium (0 and 300 mg/d per cow). Addition of monensin tended to depress feed intake and milk fat content without affecting milk production and without interactions with forage to concentrate ratios. Ruminal propionate percentage was increased more by the addition of monensin to the low forage diet than by the addition of monensin to the high forage diet. Serum urea and concentrations of nonesterified fatty acids tended to decrease when monensin was added to the high forage diet but did not change when monensin was added to the low forage diet. The results suggested that monensin had moderate positive effects on efficiency of milk production and might have an antiketogenic effect with high forage diets.

Topics: Acetic Acid; Analysis of Variance; Animal Feed; Animals; Body Weight; Cattle; Coccidiostats; Diet; Energy Metabolism; Fatty Acids, Nonesterified; Fatty Acids, Volatile; Female; Fish Products; Glycine max; Lactation; Medicago sativa; Milk; Monensin; Propionates; Rumen; Urea; Zea mays

Three experiments were conducted to evaluate elevated dietary NaCl levels as a means of offsetting industry-observed reductions of growth, feed intake, and feed efficiency associated with early (35-d) coccidiostat withdrawal. In the first experiment, monensin (100 ppm) was withdrawn and dietary salt levels of 0.33, 0.48, 0.63, 0.78, or 0.93% provided from 35 to 42 d of age. Experiments 2 and 3 involved lasalocid (110 ppm) withdrawal and slat amounts of 0.33, 0.53, 0.73, or 0.93%. In all studies, a positive control of 0.33% salt and the coccidiostat was also given. Monensin withdrawal reduced body weight gain, which was not overcome by slat addition. Feed efficiency during the 1-wk period was improved to the level of the group receiving continued medication by salt amounts of 0.78% or above. In contrast to industry field observations, removal of lasalocid did not reduce body weight gain, feed intake, or water consumption, and elevation of salt levels resulted in no consistent improvements of weight gain, feed intake, or feed conversion. Water intake increased proportionally as salt concentration increased. Elevated salt levels do not appear to be a reliable means of offsetting reduced performance related to early coccidiostat withdrawal, nor were such performance problems demonstrable for lasalocid in these trials.

Topics: Aging; Animals; Body Weight; Chickens; Coccidiostats; Dose-Response Relationship, Drug; Drinking; Eating; Lasalocid; Monensin; Sodium Chloride, Dietary; Weight Gain

Two experiments were conducted to determine the physical, chemical, and microbial properties of turkey cecal droppings and relate them to intake of common dietary components, namely fat, fiber, and the anticoccidial, monensin. Experiment 1 involved collection and analysis of physical and chemical properties of cecal and regular droppings from commercial turkey flocks. Experiment 2 tested the effect of dietary fat, fiber, and monensin on growth performance and cecal activity in male turkeys. Compared to regular excreta, cecal droppings analyzed in Experiment 1 were higher in viscosity and fat content, and lower in dry matter, nitrogen, and fiber content (P < 0.05). High dietary fiber and fat significantly (P < 0.05) improved growth performance in Experiment 2. Prolonged feeding of monensin significantly (P < 0.05) reduced cecal evacuation. Results of chemical composition showed that higher dietary fat and fiber significantly (P < 0.01) reduced the fat percentage of cecal contents, whereas prolonged feeding of monensin increased the fat in both cecal contents and droppings. There was no significant effect of any of the treatments on pH, viscosity, and microbial counts of cecal contents. There is the need to identify and characterize the compound responsible for the high viscosity of cecal droppings.

Topics: Animals; Body Weight; Cecum; Coccidiostats; Diet; Dietary Fats; Dietary Fiber; Feces; Hydrogen-Ion Concentration; Lipids; Male; Monensin; Nitrogen; Random Allocation; Turkeys; Viscosity; Weight Gain

The effects of salinomycin (20 mg kg-1 feed), monensin (33 mg kg-1 feed) and a daily rotation of these ionophores, on average daily gain (ADG), average daily feed intake (ADFI) and feed conversion efficiency (FCE) were investigated in 60 steers (273 kg) over an 84-day feedlot period. Individual feed intakes and weight gains were recorded. The data were fitted to linear regressions with individual animals as replicates, from which ADGs, ADFIs and FCEs were calculated. Means of parameters of the control, salinomycin, monensin and rotation treatments were respectively ADG (kg): 1.56, 1.74, 1.58 and 1.66; FCE (kg DM/kg): 5.83, 5.43, 5.53 and 5.38; ADFI (kg): 9.10, 9.43, 8.83 and 8.90; final weight (kg): 402, 419, 407 and 413. Salinomycin showed the greatest improvement in gain, whereas monensin did not affect gain and tended to decrease feed intake. The rotation programme did not result in added benefits above those that could be obtained with a single ionophore (salinomycin), although feed efficiency tended to increase.

Topics: Animals; Body Weight; Cattle; Diet; Ionophores; Male; Monensin; Pyrans

Experiments were conducted to determine whether the leucine catabolite beta-hydroxy-beta-methylbutyrate (HMB) could influence protein metabolism in broilers. In Experiment 1, HMB was fed at either .01 or .05% of the diet. beta-Hydroxy-beta-methylbutyrate did not improve feed conversion or BW gain; however, broilers fed HMB at .01% in a diet formulated to meet NRC (1984) recommendations had no mortality (P < .03) from 0 to 21 d of age. In Experiment 2, HMB fed at .003, .01, .03, and .09% of the diet had no significant affect on growth or carcass yield of the broilers when compared with control-fed broilers. In Experiment 3, HMB fed at .001, .003, and .01% of the diet had no effect on broiler growth. In Experiment 4, HMB was fed at .01% of the diet in combination with an antibiotic and coccidiostat (GP). Use of GP increased (P < .01) BW, feed conversion, and carcass yield when compared with the control broilers. In Experiment 5, HMB was fed at .1% of the diet, and effects of sex and GP were examined. beta-Hydroxy-beta-methylbutyrate decreased (P < .01) mortality by 72% in the male broilers. In a combined analysis, HMB fed at .01% of the diet (Experiments 1, 2, and 3) increased breast yield (P < .05) and reduced mortality by 56% (P < .04) from 0 to 21 d of age. In a combined analysis, HMB fed at .003% of the diet (Experiments 2 and 3) increased 42-d BW (P < .02) and hot (P < .04) and chilled (P < .05) carcass yields. In conclusion, across all HMB dosages mortality of male broilers was decreased from 6.37 to 4.39% (-31%, P < .04) by feeding HMB, with the pattern of death suggesting that HMB decreased the incidence of sudden death syndrome in these broilers.

Topics: Animal Feed; Animals; Bacitracin; Body Weight; Chickens; Female; Food, Fortified; Male; Monensin; Mortality; Random Allocation; Valerates

Broiler chicks were kept on feeds amended by the addition of 240 mg monensin and 15 mg selenium with or without 200 mg vitamin E/kg. After 12 days, birds in different groups were orally administered three doses of 250 mg monensin and 5 mg selenium/kg body weight. In the second experiment, after four weeks of adaptation on amended feeds, similar groups were orally administered 40 mg monensin and 1 mg selenium/kg body weight on alternate days for four weeks. Monensin increased the liver iron level. Selenium increased the hepatic levels of selenium and iron while variable degrees of depression occurred in copper, zinc, manganese and magnesium levels. Concurrent administration of monensin and selenium significantly increased the liver selenium levels. A marked decrease in body weight and increased mortality were recorded due to concurrent administration of monensin and selenium.

Topics: Administration, Oral; Animals; Body Weight; Chickens; Drug Interactions; Liver; Monensin; Mortality; Selenium

Two hundred eighty-eight beef steers (British x Continental x Brahman) were fed a 90% concentrate diet containing either no ionophore (control), laidlomycin propionate at either 6 or 12 mg/kg of dietary DM, or monensin plus tylosin (31 and 12 mg/kg of DM, respectively). Neither of the two levels of laidlomycin propionate nor monensin plus tylosin affected (P greater than .10) ADG or feed:gain ratio. Monensin plus tylosin reduced (P less than .01) daily DMI for the 161-d trial period compared with the other three treatments. Laidlomycin propionate at 6 mg/kg increased (P less than .05) DMI relative to the control, laidlomycin propionate at 12 mg/kg, and monensin plus tylosin diets during the 2nd wk of the trial and from d 57 to 84. Treatments did not affect carcass measurements. In a second experiment, 12 ruminally cannulated steers were fed diets containing no ionophore or laidlomycin propionate at either 6 or 12 mg/kg of DM. Samples were obtained for two consecutive days while the dietary concentrate level was 75%, after which the diet was switched abruptly to 90% concentrate, and samples were collected on several days during a 21-d period. The rate at which steers consumed their daily allotment of feed was not altered markedly by laidlomycin propionate. Likewise, laidlomycin propionate did not affect total ruminal VFA concentrations or proportions. Ruminal concentrations of D-lactate were reduced (P less than .10) by 6 but not by 12 mg/kg of laidlomycin propionate.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Ammonia; Animal Feed; Animals; Body Weight; Cattle; Eating; Fatty Acids, Volatile; Fermentation; Hydrogen-Ion Concentration; Male; Monensin; Rumen; Tylosin

Monensin sodium (0, 15, or 30 mg/kg of complete feed) was fed ad libitum for 1 week to female mice (strain C57BL6/J) that were genetically susceptible to infection with Mycobacterium paratuberculosis. Ten mice in each of the 3 groups were inoculated intraperitoneally with M paratuberculosis (10(9) organisms). Sterile saline solution was injected intraperitoneally into 10 other mice in each group. Rations were continued for 50 days, then mice were euthanatized, and body weight, splenic weight, and hepatic weight for each mouse were recorded. Ratios of body weight to splenic weight and of body weight to hepatic weight were calculated for each mouse. Hepatic granulomas in 50 light microscopic fields were counted, and presence of acid-fast organisms in those granulomas was recorded. Infected mice given monensin had higher body weight and fewer hepatic granulomas than did mice not given monensin. Although hepatic granulomas were fewer in these mice, they contained acid-fast organisms. Effects of 15 mg of monensin and those of 30 mg of monensin/kg of complete feed were not different.

Topics: Animals; Body Weight; Female; Granuloma; Liver; Liver Diseases; Mice; Mice, Inbred C57BL; Monensin; Organ Size; Paratuberculosis; Spleen

The utilization of carboxylic ionophores such as monensin for immunotoxin potentiation may be hampered by the poor solubility and short in vivo half-life of these highly lipophilic compounds. Therefore, the use of monensin formulated in a lipid/water emulsion was investigated for the in vitro and in vivo potentiation of immunotoxins. Monensin in emulsion or in buffer was equally effective for the in vitro potentiation of the cytotoxicity of both anti-human transferrin receptor and anti-carcinoembryonic antigen immunotoxins against target cells. In mice, buffer and lipid emulsion were compared as vehicles for the i.p. administration of monensin. The half-life of monensin in the peritoneal cavity of BALB/c x DBA/2 F1 (CD2F1) mice was increased 20-fold by inclusion in lipid emulsion (13 min versus 0.75 min). Treatment i.p. with anti-human transferrin receptor immunotoxin or anti-carcinoembryonic antigen immunotoxin and monensin emulsion prolonged the survival of mice with macroscopic i.p. tumor xenografts of H-Meso-1 mesothelioma and LS174T colorectal carcinoma (200-250% increased length of median survival). The in vivo antitumor effect of the cell-specific immunotoxin plus monensin emulsion was superior to immunotoxin alone or to immunotoxin plus monensin in buffer (P less than 0.03; Mann-Whitney U test). This indicates that delivery of monensin in preformed lipid emulsion may produce a reservoir effect of the ionophore in the peritoneal cavity of tumor-bearing mice. Nonspecific control immunotoxin plus monensin emulsion produced no increase in survival. Long-term tumor-free survival (greater than 150 days versus a median survival of 25 days for controls) of mice bearing microscopic LS174T xenografts was obtained by treatment with anti-human transferrin receptor immunotoxin plus monensin emulsion. Administration of either monensin in buffer or monensin in emulsion without immunotoxin had no significant effect on survival. Monensin in this pharmacologically available form significantly improved the in vivo efficacy of both anti-human transferrin receptor immunotoxin and anti-carcinoembryonic antigen immunotoxin when used as regional therapy.

Topics: Animals; Antibodies, Monoclonal; Body Weight; Cell Line; Cell Survival; Colorectal Neoplasms; Drug Synergism; Emulsions; Half-Life; Humans; Immunotoxins; Mesothelioma; Mice; Mice, Nude; Monensin; Ricin; Transplantation, Heterologous; Tritium

Broilers were grown to 42 days of age on diets supplemented with salinomycin (60 mg/kg), monensin (99 mg/kg), or halofuginone (3 mg/kg) and continued on unmedicated diets to 49 days of age. There were no significant (P greater than .05) differences among anticoccidials in final body weight, feed conversion, or mortality rates. Samples of birds were processed for dressing percentage and parts yield. Both males and females fed salinomycin had significantly higher breast meat yield as a percentage of postchill weight than those fed halofuginone but not those fed monensin; differences were not significant for breast meat yield of males or females fed monensin or halofuginone. Males fed halofuginone had significantly heavier leg quarters than those fed salinomycin but not those fed monensin. Females fed salinomycin had significantly higher water uptake during chill than those fed monensin or halofuginone. Results of the present study indicate that the anticoccidial used in growing broilers may influence some carcass yield parameters.

Topics: Animals; Body Weight; Chickens; Coccidiostats; Eating; Female; Male; Monensin; Muscle Development; Muscles; Piperidines; Pyrans; Quinazolines; Quinazolinones; Random Allocation

1. Two experiments were performed to evaluate the potential of phenylpropanolamine hydrochloride and monensin sodium as appetite- and weight-control agents for Indian River broiler breeder chicks. 2. In experiment 1, a total of 300 day-old sexed broiler breeder chicks were individually weighed and placed in battery cages. They were randomly assigned to 5 dietary treatments, namely 0, 50, 100, 200 and 400 mg/kg of phenylpropanolamine hydrochloride added to a maize-soyabean meal basal diet. 3. In experiment 2, a total of 400 day-old sexed broiler breeder chicks were randomly assigned to 10 dietary treatments which were a combination of two concentrations of dietary crude protein (200 and 150 g/kg) and 5 different concentrations of added drugs in the diet, namely 0, 500 and 800 mg/kg of phenylpropanolamine hydrochloride and 200 and 300 mg/kg of monensin sodium. 4. Food consumption and body weight gain were significantly reduced by feeding diets containing the drugs but mortality was not significantly affected. Birds showed evidence of increased tolerance, with age, to phenylpropanolamine but not to monensin. 5. Monensin sodium, at high inclusion rates, was found to be a more potent and effective appetite- and growth-depressing agent for broiler breeder chicks than phenylpropanolamine and may have application in broiler breeder production using an ad libitum feeding programme.

Topics: Animal Feed; Animals; Body Weight; Chickens; Dietary Proteins; Eating; Female; Male; Monensin; Phenylpropanolamine; Random Allocation

Ninety-six commercial broiler chicks housed in battery brooders were exposed to experimental diets varying in monensin (50, 250 mg/kg) and sodium selenite (0, 10 mg/kg) levels from their 10th to 25th day of age. Feed and water were supplied ad libitum. There were 4 replications of each experimental treatment, each with 6 birds/replication. The data on bird weights showed a significant treatment effect for monensin, sodium selenite, and an interaction between the 2. High levels of monensin and sodium selenite decreased weight, the combination exacerbating this response. The residue data showed that chicks accumulated significantly higher concentrations of selenium in their tissues when on diets high in sodium selenite. Chicks also accumulated significantly higher concentrations of monensin in their tissues when on diets high in monensin. An interactive effect was observed in terms of the selenium residue data, high levels of dietary monensin decreased the selenium residue concentration in the liver, kidney and cardiac muscle tissues when on high sodium selenite diets. No interactive effect was observed in terms of the monensin residue data. Pathological lesions, which were expected but not observed, may also indicate an interaction between these compounds.

Topics: Animals; Body Weight; Chickens; Diet; Male; Monensin; Organ Size; Selenium; Sodium Selenite

Four experiments were conducted to investigate if the degree of activation of the microsomal mixed-function oxidase (MFO) system was related to the degree of growth depression associated with the addition of monensin to the diet. The experiments were conducted with broiler chicks in battery brooders in which the chicks were fed diets of various composition and containing monensin at 0 to 160 ppm. In all experiments, the activity of the MFO system was estimated by the change in the content of cytochrome P-450 in the hepatic microsomes. Activities of some microsomal enzymes were also measured in some of the experiments. Feeding a diet with 24% protein containing fish meal, alfalfa meal, and torula yeast significantly increased the activity of the MFO system in comparison with feeding an isonitrogenous and isoenergetic corn and soybean diet, but there was no difference between the diets in the toxicity of monensin as measured by growth rate. Supplementing a 16% protein but not a 24% protein diet with monensin significantly reduced growth rate. In none of the four experiments was there a statistically significant change in the hepatic content of cytochrome P-450 as a result of feeding monensin. Thus, variation in the magnitude of growth depression caused by monensin in diets of different protein concentration or ingredient composition does not appear to be explained on the relative degree of the activation of the MFO system.

Topics: Animal Feed; Animals; Body Weight; Chickens; Cytochrome P-450 Enzyme System; Growth Inhibitors; Male; Microsomes, Liver; Mixed Function Oxygenases; Monensin

Lasalocid and monensin are widely used to control coccidiosis in broilers, but not in turkey poults. Four feeding trials were conducted to determine the performance of turkey poults when these compounds were used singly or in combination with 100 ppm of furazolidone. Bodyweights and feed consumption were significantly depressed for five weeks after hatching by 150 ppm of lasalocid. Combining furazolidone with lasalocid ameliorated the toxic effect of lasalocid. Bodyweights were significantly depressed by 150 ppm of monensin in the fifth week after hatching, but there was no significant depression in feed consumption. Furazolidone exacerbated any toxic effects of monensin. Data indicate that monensin may be used safely at dosages greater than the recommended level of 60 to 99 ppm, but should not be used in combination with furazolidone.

Topics: Animal Feed; Animals; Bacterial Infections; Body Weight; Coccidiosis; Drinking; Drug Interactions; Eating; Furazolidone; Lasalocid; Male; Monensin; Poultry Diseases; Random Allocation; Turkeys

The effects of ionophores on liver weight and function were determined in finishing steers (n = 24; avg weight 440 kg). Steers were group-fed one of three treatments (control, lasalocid or monensin at 33 mg/kg feed) for 46 d prior to slaughter. Three days prior to slaughter, blood was collected for the determination of serum Ca and Mg. At slaughter, the liver was removed, weighed, sampled, frozen in liquid nitrogen and subsequently analyzed for concentrations of carbohydrate metabolites and minerals. Liver weight (5.9 kg) was unaffected by treatment. Serum and hepatic Ca and Mg were not affected by ionophore treatment. Hepatic glycogen levels in steers fed ionophores were unaffected by treatment. Fructose 1,6-bisphosphate was 21% lower (P less than .10) in hepatic tissue of steers fed ionophores, whereas dihydroxyacetone phosphate was 15 to 37% greater in hepatic tissue of steers fed monensin (P less than .20) or lasalocid (P less than .10). Glyceraldehyde 3-phosphate was elevated more extensively by lasalocid than by monensin with increases of 72 (P less than .05) and 132% (P less than .001), respectively, over controls. Glycerol 3-phosphate levels were 37% (P less than .05) and 12% (NS) greater with these ionophores. Hepatic levels of pyruvate were elevated 12 (NS) to 36% (P less than .17) for monensin and lasalocid. Fructose 2,6-bisphosphate levels were 25% lower (P less than .25) in hepatic tissue of steers fed ionophores than in hepatic tissue from control steers. Other metabolites of carbohydrate metabolism in hepatic tissue were not altered appreciably. Changes in levels of intermediary metabolites of carbohydrate metabolism suggest alterations in hepatic carbohydrate metabolism favoring gluconeogenesis in steers fed ionophores.

Topics: Animals; Body Weight; Calcium; Carbohydrate Metabolism; Cattle; Ionophores; Lasalocid; Least-Squares Analysis; Liver; Liver Glycogen; Magnesium; Male; Monensin; Organ Size; Random Allocation

Because monensin and salinomycin are widely used to control coccidiosis, two experiments were conducted to compare the performance of broiler chicks when these compounds were added to the diet. Five levels of each coccidiostat were fed. Increasing the levels of coccidiostat resulted in a decrease in body weight and feed intake. Monensin gave a greater depression at the level suggested by the manufacturer for prevention of coccidiosis (121 ppm) than did salinomycin (66 ppm). The interaction of experiment x treatment was significant and was a result of the greater performance depression at the lower levels (manufacturers' recommended levels) of coccidiostat administered in the first experiment than in the second. This research points out the necessity of the accurate use of the coccidiostats.

Topics: Animals; Body Weight; Chickens; Coccidiostats; Female; Ionophores; Male; Monensin; Pyrans

Monensin, a monocarboxylic acid ionophore, is an effective anticoccidial agent in chickens. Arsanilic acid is a widely used growth promoter in chickens. A dietary interaction between these 2 compounds was studied. Male broiler (Hubbard) chicks were offered 1 of 8 experimental diets containing these 2 compounds from their tenth until 32nd day of age. These diets consisted of a base of 26.5% corn, 26.5% wheat, and 37.5% soybean meal and had an energy value of 12.98 mJ/kg. Monensin varied in concentration from 50 to 200 mg/kg and arsanilic acid varied in concentration from 0 to 500 mg/kg. Arsanilic acid was found to significantly alter the pattern of weight gain among birds. An interaction was observed to occur between monensin and arsanilic acid only in terms of final bird weights. Growth depression, normally associated with monensin supplementation, was alleviated by arsanilic acid addition. There were no differences among the 8 groups based on gross pathological and histological examination of the birds. Tissue arsenic concentrations were found to increase with increasing dose of arsanilic acid in the diet. No tissue monensin concentrations were detectable by the methodology used.

Topics: Animals; Arsanilic Acid; Arsenic; Arsenic Poisoning; Body Weight; Chickens; Diet; Drug Interactions; Male; Monensin

Two groups of fattened bulls (125 bulls in each group) were investigated for the effect of monensin (125-175 mg per head/day) on live weight gains and for the effectiveness of monensin administration. After 160 days of fattening, the average daily weight gain was 713 g in the control group and 800 g in the monensin-treated group (an increase by 12.2%). After 11 months of fattening the daily weight gain was 702 g in the control group and 768 g in the monensin-treated group (an increase by 9.4%). Besides the control and experimental groups, monensin was administered to 1500 head of fattened cattle on the whole. Greater differences in the daily live weight gains (higher gains in the monensin-treated animals) were recorded mainly in the period when the feed ration contained high-quality bulk feeds. When the bulls were given feeds of lower quality (mainly late in winter), the differences in the average daily live weight gains decrease and the effect of monensin treatment is not so great. Throughout the fattening period, monensin had a favourable influence on the live weight gains and its use was economically advantageous.

Topics: Animal Feed; Animals; Body Weight; Cattle; Male; Monensin

Three chick growth assays were conducted to investigate the effects of monensin on lysine and arginine utilization in crossbred chicks (New Hampshire X Columbian). Chicks were fed either a low lysine corn-sesame meal diet containing graded increments of crystalline lysine.HCl (Assay 1) or an arginine-deficient casein-dextrose diet (Assay 2) supplemented with graded levels of L-arginine.HCl in the presence or absence of supplemental monensin (121 mg/kg). Based upon analysis by slope-ratio methodology (i.e., gain regressed on supplemental amino acid intake), the efficiency of L-lysine or L-arginine utilization was found to be the same in both monensin-fed and control chicks. In Assay 3, effects of monensin on the lysine-arginine antagonism were studied. Chicks were fed an arginine-deficient casein-dextrose diet supplemented with 1 or 2% L-lysine.acetate in the presence or absence of supplemental monensin. Growth performance was depressed by feeding both levels of supplemental L-lysine.acetate. Monensin had no effect on the magnitude of the growth depression caused by supplemental lysine. These results support the view that neither lysine nor arginine utilization is impaired by feeding monensin.

Topics: Animals; Arginine; Body Weight; Chickens; Lysine; Male; Monensin

Topics: Animals; Body Weight; Chickens; Enzymes; Liver; Monensin; Muscles; Myocardium

Two comparative slaughter trials and a metabolism trial were conducted. Treatments consisted of: 1) 0 fat, 0 monensin; 2) 4% yellow grease, 0 monensin; 3) 0 fat, 33 mg/kg monensin and 4) 4% yellow grease, 33 mg/kg monensin. Trial 1 involved 104 crossbred beef steers (267 kg) in a 140-d comparative slaughter trial. There were no interactions (P greater than .20) between supplemental fat and monensin on steer performance. Monensin supplementation decreased rate of weight gain (P less than .10) and feed intake (P less than .05) with no effect on energy value of the diet (P greater than .20). Fat supplementation increased (P less than .01) rate of weight gain 12.5% and increased the net energy for maintenance (NEm) and net energy for gain (NEg) value of the diet 8.5 and 9.4%, respectively. Trial 2 involved 154 Holstein steers (290 kg) in a 94-d comparative slaughter trial. There were no interactions between supplemental fat and monensin (P greater than .20). Monensin supplementation did not affect rate or composition of gain (P greater than .20), but supplementation reduced (P less than .05) feed intake and feed required per unit weight gain 3.6%. Fat supplementation increased (P less than .01) fat and energy gain 12.5 and 10.3%, respectively, and the NEm and NEg content of the diet 7.5 and 8.4%, respectively. Trial 3 utilized four crossbred beef steers (220 kg) with cannulas in the rumen, proximal duodenum and distal ileum. There were no interactions between supplemental fat and monensin with respect to site of digestion (P greater than .20). Supplemental fat did not affect (P greater than .20) organic matter, starch, fiber or N digestion. Intestinal digestibility of fat averaged 77.3%. Monensin increased (P less than .10) intestinal digestibility of fat 7.4%. There were negative associative effects between supplemental fat and monensin on ruminal acetate:propionate ratios and estimated methane production. It was concluded that the feeding value of feed fat is underestimated in tables of feed standards currently in use, and that the net effects of monensin on these estimates are additive.

Topics: Animal Feed; Animals; Body Weight; Cattle; Dietary Fats; Male; Monensin

Two finishing trials were conducted to measure the response of cattle adjusting to high-concentrate diets to dietary monensin level. In trial 1, 54 individually fed Hereford-Angus steers (312 kg), previously fed a two-thirds corn silage: one-third corncob-based diet, were allotted in a 2 X 3 factorial arrangement of treatment with tylosin (0, 11 mg/kg) and monesin (0, 11, 33 mg/kg) fed during a 28-d, grain-adaptation period (fed 75% concentrate for 6 d and then fed 95% concentrate). After 28 d, all steers were continued on their respective levels of tylosin and 33 mg/kg monensin for the remaining 119 d. Daily intake patterns indicated digestive upset in all treatments during adjustment to the 95%-concentrate diet. Blood samples taken during the first 28 d revealed no differences in acid-base status in response to monensin level; however, all steers exhibited reduced (P less than .01) pH and HCO3 and increased (P less than .01) lactate after 4 d on a 75%-concentrate diet. In the initial 28 d, intake decreased (linear P less than .05) as the level of monensin increased. In the total finishing period, however, increasing the level of monensin fed during grain adaptation decreased (linear P less than .05) intake and tended to decrease (linear P = .20) gain with no effect on feed efficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acidosis; Adaptation, Physiological; Animal Feed; Animals; Body Weight; Cattle; Edible Grain; Leucomycins; Male; Monensin

1. The performance of 1680 male broiler chickens was measured from one to 42 d of age. They were given diets with three (125, 165 and 205 mEq/kg) electrolyte balances (sodium + potassium - chloride), two sources of added potassium (carbonate or sulphate) and two anticoccidial agents (90 mg/kg of either monensin or lasalocid). 2. The dietary treatments had no significant effects on the growth performance of broiler chickens in the starter phase. 3. In the finisher phase, the chickens given the diets containing lasalocid utilised food less efficiently that those given the diets containing monensin. 4. There were significant interactions between dietary electrolyte balance and source of added potassium on body weight gains and food:gain ratios in the finisher phase. In diets with an electrolyte balance of 205 mEq/kg, the inclusion of potassium sulphate instead of potassium carbonate increased body weight gains by 3.4% and reduced food:gain ratios by 4.6%. 5. The body weight gains of chickens given the finisher diets containing lasalocid and added potassium carbonate were reduced by 2.6% compared to those of chickens given the diets containing monensin or added potassium sulphate. 6. The litter moisture content was higher in pens with chickens on the diets with an electrolyte balance of 205 mEq/kg than on the diets with either 125 or 165 mEq/kg. Both lasalocid and potassium sulphate tended to increase the litter moisture content. 7. It may be concluded that the inclusion of 90 mg/kg of either monensin or lasalocid in broiler diets does not alter the balance of electrolytes required for optimum growth performance of broiler chickens.

Topics: Animals; Body Weight; Chickens; Lasalocid; Male; Monensin; Potassium; Sodium, Dietary

The activities of five anticoccidials were compared against Eimeria species in/of chickens, in controlled in vivo and in vitro laboratory studies. Two more recent and potent market entries (maduramicin and halofuginone) were compared with three older polyether antibiotic anticoccidials (monensin, lasalocid and salinomycin). Halofuginone, lasalocid, maduramicin, monensin and salinomycin were evaluated at 3, 125, 5, 120 and 66 ppm, respectively, of active drug in the diets. At these levels, all five drugs demonstrated significant activity against Eimeria tenella, E. maxima, E. necatrix, E. brunetti and E. acervulina (in vivo). Monensin was least effective against E. tenella, and one of the lesser efficacious drugs against E. necatrix, maduramicin, was least effective against E. maxima. In studies of single Eimeria species infections, comparable weight gains were noted for the drugs. In the mixed Eimeria species infections, however, birds treated with maduramicin had significantly higher weight gains than did birds medicated with monensin. Unlike in vivo potencies, titration in vitro indicated that monensin was most potent (active at 10(-6) mcg ml-1), and maduramicin and lasalocid least potent (inactive at less than or equal to 10(-3) mcg ml-1).

Topics: Animals; Anti-Bacterial Agents; Body Weight; Chickens; Coccidiosis; Coccidiostats; Eimeria; Female; Ionophores; Lactones; Lasalocid; Male; Monensin; Piperidines; Poultry Diseases; Pyrans; Quinazolines; Quinazolinones

A total of 768 female broiler chicks in two experiments was fed diets containing 0, 100, or 120 mg monensin/kg of diet with and without added animal fat, in a 2 X 3 factorial design. Chicks were grown in electrically heated battery brooders and supplied feed and water ad libitum for 21 days. Animal fat fed at 6.8% of the diet consistently improved body weight, daily feed intake, and feed conversion regardless of monensin level. Monensin at 100 and 120 mg/kg of diet, in general, decreased these performance criteria progressively. Daily monensin intake was related to the concentration of monensin in the diet. Intake per unit of body weight was increased by reducing fat or increasing monensin.

Topics: Animal Feed; Animals; Body Weight; Chickens; Energy Metabolism; Female; Monensin

Three experiments were conducted to evaluate the influence of dietary protein source on the monensin response in healthy chicks fed diets varying in CP. The interrelationship between dietary CP level and four different anticoccidial drugs was evaluated in a fourth experiment. The experiments were conducted from 8 to 21 or 22 days posthatching. In Experiment 1, crossbred chicks were fed corn-soybean meal (SBM) diets containing either 24 or 16% CP or casein-dextrose diets containing 20, 15, or 10% CP in the presence or absence of 160 mg/kg monensin. When CP level was decreased in the corn-SBM treatments, the resulting monensin-induced growth depression was greater. However, this interaction was not observed in chicks fed casein-dextrose diets. Experiments 2 and 3 were conducted to determine if the monensin-protein level interrelationship is influenced by the source of dietary soybean protein or by high levels of animal protein (AP). Monensin at 140 mg/kg produced a much greater growth depression at 16 than at 24% CP in chicks fed a corn-SBM diet, whereas amounts of monensin depression in chicks fed a corn-isolated soy protein diet were similar for both CP levels. As dietary protein was reduced from 24 to 16% in Experiment 3, 140 mg/kg monensin caused growth depressions of 10 and 40%, and 14 and 28%, respectively, in broiler chicks fed corn-SBM and corn-AP diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Weight; Chickens; Coccidiostats; Dietary Proteins; Male; Monensin

Primary cultures of rat hepatocytes were used to study the effect of acute and chronic ethanol exposure on alpha-tocopherol content in cells and media. Cells treated acutely with 60 mM ethanol secreted 74.5 +/- 18.0% (P less than 0.05), and their cellular alpha-tocopherol content was 85.7 +/- 15.4% (not significant) of controls after 20 h incubation. At this time total recovery of alpha-tocopherol was significantly reduced in ethanol-exposed cells (43.1 +/- 8.4%) as compared to control cells (52.8 +/- 5.0%, P less than 0.05). Hepatocytes isolated from chronic ethanol-fed rats (35% of total energy intake as ethanol for 5 weeks) secreted 41.9 +/- 12.7% less alpha-tocopherol than did cells of pair-fed controls during 20 h incubation (P less than 0.05). The amount of alpha-tocopherol secreted was then 15.6 +/- 4.2 and 19.8 +/- 3.8% of cell-associated alpha-tocopherol at start of incubation for chronic ethanol-fed and control rats, respectively (P less than 0.05). When 60 mM ethanol was added to the incubation medium, hepatocytes of control rats secreted significantly less alpha-tocopherol (about 30%, P less than 0.05), whereas alpha-tocopherol secretion was not significantly reduced in hepatocytes of chronic ethanol-fed rats. We conclude that both acute and chronic ethanol exposure reduce alpha-tocopherol secretion from rat hepatocytes.

Topics: Animals; Body Weight; Cells, Cultured; Colchicine; Diet; Eicosapentaenoic Acid; Ethanol; Liver; Male; Monensin; Rats; Rats, Inbred Strains; Vitamin E

Two groups of bullocks, each consisting of 125 animals, were subjected to a trial to study the effect of monensin (Rumensin premix) administered at doses from 125 to 175 mg per head/day on rumen fermentation and weight gains. For 135 days the animals were given a diet based on green juicy forage with a supplement of chopped straw and concentrate mixture; this mixture contained 20-30% of dried poultry droppings. In the experimental group with monensin, the concentration of total and protein nitrogen and the molar percentage of propionic acid significantly increased (23.7 and 28.5%, respectively, P less than 0.01) and the acetate: propionate ratio decreased four hours after feeding. Further, the energy yield of the production by volatile fatty acids (VFA) significantly increased in the rumen contents (76.89%, 78.64%, respectively, P less than 0.05). The levels of ammonia and non-protein nitrogen were not affected by the addition of monensin. The average daily live weight gains were 713 g in the control group and 800 g in the experimental group; this means that the gains of the experimental animals rose by 12.2%. Monensin had a positive influence on the proportions of the rumen-produced VFA in favour of propionic acid which, in turn, favourably influenced the energy balance of nutrient conversion and efficiency.

Topics: Animal Feed; Animals; Body Weight; Cattle; Fatty Acids, Volatile; Fermentation; Male; Monensin; Rumen

Sixty-four Angus steers initially averaging 354 kg were allotted to a 2 X 2 factorial arrangement of treatments to determine the effects of dietary Ni (0 or 5 mg/kg supplemental), monensin (0 or 33 mg/kg) and their possible interaction on performance, methane production and N metabolism. The basal diet was a high energy, corn-cottonseed hull based diet containing 10.2% crude protein and .30 mg/kg Ni on a dry matter basis. Monensin reduced (P less than .05) feed intake, did not affect average daily gain and improved (P less than .05) feed conversion over the 102-d study. Nickel supplementation did not significantly alter or interact with monensin to affect steer performance. However, steers fed Ni tended to have higher average daily gains and improved feed conversions. Monensin decreased (P less than .05) in vitro methane production, altered several carcass traits, increased (P less than .05) molar proportion of ruminal propionate and decreased (P less than .05) molar proportion of ruminal acetate. Nickel did not alter methane production, carcass characteristics or ruminal volatile fatty acid proportions. Both monensin and Ni increased (P less than .05) ruminal fluid urease activity when samples were obtained before feeding. A significant monensin X Ni interaction was found to affect ruminal epithelial urease activity. Monensin increased ruminal epithelial urease in steers not receiving supplemental Ni, but had no effect on ruminal epithelial urease activity in steers fed supplemental Ni. Ruminal fluid protein and ammonia-N were decreased (P less than .05) by monensin. Results of this study indicate that Ni may interact with monensin to affect ruminal epithelial urease activity but not performance or methane production in finishing steers.

Topics: Animals; Body Weight; Cattle; Male; Methane; Monensin; Nickel; Nitrogen

Alborixin, a polyether antibiotic with ionophore properties, was evaluated to determine the effect of the drug on weight gain of chickens and to define the anticoccidial spectrum of activity. The 50-ppm concentration in the diet was identified as the maximum level that did not significantly reduce weight gain beyond that of monensin (standard drug); consequently, the drug was evaluated for anticoccidial activity at this dilution. At the 50-ppm level, alborixin demonstrated broad-spectrum anticoccidial activity; however, the drug lacked Eimeria necatrix efficacy. Monensin and maduramycin were significantly more efficacious than alborixin as a treatment for several species of Eimeria. Higher concentrations of alborixin (greater than 50 ppm) appear essential to achieve broad-spectrum and comparable anticoccidial activity, however, these levels substantially depressed weight gains. Alborixin is similar to many other polyethers in that weight gains are adversely affected at drug levels essential for solid broad-spectrum anticoccidial activity.

Topics: Animals; Body Weight; Chickens; Coccidiostats; Eimeria; Monensin; Pyrans

We studied the effect of sulfadiomethoxine and ormetoprim (Rofenaid 40) in combination with lasalocid (Avatec) and monensin (Coban) on mortality, weight gain, and feed conversion of 2592 male broilers to 47 days of age. Four shuttle treatments were utilized: 1) monensin feeding for the entire trial; 2) sulfadimethoxine and ormetoprim feeding for the first 2 weeks, followed by lasalocid for the remainder of the trial; 3) sulfadimethoxine and ormetoprim feeding for the first 2 weeks, followed by monensin; and 4) sulfadimethoxine and ormetoprim feeding through week 3, then lasalocid for the remainder of the trial. No significant (P greater than .05) differences were observed in mortality among the four treatments. The combination of sulfadimethoxine and ormetoprim plus lasalocid significantly (P less than .01) improved weight gain and final body weight, but the length of time that sulfadimethoxine and ormetoprim were fed did not have any effect. Sulfadimethoxine and ormetoprim plus monensin treatment resulted in better feed conversion as compared with the other treatments.

Topics: Animals; Body Weight; Chickens; Lasalocid; Male; Monensin; Pyrimidines; Sulfadimethoxine

Two trials were conducted to characterize the differences in utilization of dry-rolled and steam-flaked corn in a growing-finishing diet for feedlot cattle supplemented with and without ionophores. Ionophore treatments were: 1) no ionophore, 2) 33 mg/kg monensin sodium plus 11 mg/kg tylosin and 3) 33 mg/kg lasalocid sodium. In trial 1, treatment effects on feedlot performance were evaluated in a 239-d growing-finishing trial involving 180 crossbred steers (approximately 25% Brahman with the remainder represented by Hereford, Angus, Shorthorn and Charolais breeds in various proportions) with an average initial weight of 153 kg. In trial 2, treatment effects on characteristics of digestion were evaluated using six steers of similar breeding and background to those used in trial 1, with cannulas in the rumen and proximal duodenum. There were no interactions between corn processing and ionophore supplementation (P greater than .20). Average daily gain was not affected by steam-flaking as opposed to dry-rolling, however, feed intake was decreased 5.4% and feed conversion was improved 6.8% (P less than .01). Steam-flaking increased the estimated net energy value of the diet 7.7% and 8.5% for maintenance and gain, respectively (P less than .01). Steam-flaking increased the digestibility of starch 6.6% (P less than .01). Steam-flaking increased ruminal molar concentrations of propionate and decreased acetate:propionate ratio and estimated methane production (P less than .10). Both monensin-tylosin and lasalocid resulted in reduced feed intake (12.3 and 6.5%, respectively, P less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animal Feed; Animals; Body Weight; Cattle; Digestion; Lasalocid; Leucomycins; Male; Monensin; Nutritive Value; Zea mays

The effects of dietary fat level, fat source, and protein level on the growth response of broiler chicks were evaluated in two experiments with a factorial design. A higher level of soybean oil (SO) (3.5 vs. .5%) in diets containing either 18.2 or 20.4% protein significantly (P less than .05) counteracted the depressing effect of monensin on feed intake and weight gain in male chicks in the first experiment. Dietary protein level did not significantly (P greater than .05) affect the response to monensin, nor did monensin affect feed to gain ratio. The higher SO level of 3.5% in diets containing 18.2% protein reduced, at times significantly (P less than .05), the depressing effect of monensin on feed and water intake, water to feed ratio, weight gain, and the retention of dry matter and nitrogen in female chicks in the second experiment. A similar higher level of tallow resulted in less pronounced effects on most of the parameters. Monensin supplementation did not affect dietary metabolizable energy content, but significantly (P less than .01) increased feed to gain ratio and the percent of fecal dry matter. It was concluded that the toxicity of monensin to chicks might be alleviated by increasing dietary unsaturated fat and protein levels.

Topics: Animals; Body Weight; Chickens; Dietary Fats; Dietary Proteins; Female; Male; Monensin

Four experiments were conducted to evaluate the effect of monensin feeding and withdrawal on broiler performance and carcass characteristics. It was shown that monensin (100 ppm) feeding depressed growth. Withdrawal of monensin from the feed for 5 or 7 days produced higher feed consumption and weight gain values compared with those of unmedicated broilers. Increasing the withdrawal period to 10 days did not produce greater growth improvement. Whole body composition of protein, water, lipid, and ash were not significantly affected by monensin feeding or withdrawal. Abdominal fat pads of unmedicated female broilers were significantly larger than those of broilers medicated with monensin even when expressed as a percentage of body weight (3.53 vs. 2.99%). Amount of lipid per fat pad was also higher in unmedicated broilers than in medicated broilers (43.5 vs. 30.6 g). Values for fat pad weight (as a percentage of body weight) and grams of lipid per fat pad of unmedicated birds were not different from those measures in medicated birds after 5 or 7 days of withdrawal. Fat pad weights and lipids per fat pad of birds after 10 days of monensin withdrawal were intermediate between those of unmedicated and monensin-medicated broilers. Monensin feeding or its withdrawal for 5 or 10 days did not influence the female broiler abdominal fat pad lipid fatty acid composition when compared with that of unmedicated fat pad lipid.

Topics: Animal Nutritional Physiological Phenomena; Animals; Body Composition; Body Weight; Chickens; Female; Male; Monensin; Sex Characteristics

The breeding performance of broiler breeder chickens previously raised on high levels of monensin was evaluated. The birds were raised on concrete floors in an open-sided pullet brooding and growing house. At 21 weeks of age monensin feeding was stopped and birds were placed in the breeder house. A breeder ration formulated to contain 2,920 kcal metabolizable energy and 16% crude protein was fed to all the birds irrespective of the growing system used. A standard feeding allowance and lighting program as recommended by Indian River International was followed during the laying period. The parameters determined were body weight uniformity at 21 weeks of age, egg production, egg weight, shell weight, shell thickness, feed conversion (kilograms feed/dozen eggs), mortality, fertility, and hatchability. Assays for monensin residue in the breast muscle, liver, and abdominal fat were run at 52 weeks of age (31 weeks after monensin withdrawal). Birds grown on high levels of monensin were not as uniform in body weight at 21 weeks of age as the restricted controls. Only birds fed 400 ppm of monensin with a low protein diet during the growing period showed a significant reduction in egg production, shell weight, and shell thickness. There were no significant differences among the growing systems in mortality during lay, fertility, hatch of fertile eggs, and hatch of total eggs. Monensin was not detectable (less than .1 ppm) in the liver, abdominal fat, and breast muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animal Feed; Animals; Body Weight; Chickens; Dietary Proteins; Egg Shell; Female; Male; Monensin; Oviposition

Three series of trials were conducted to evaluate the effect of monensin on the growth performance of cattle. Twenty-four trials were conducted to evaluate the addition of monensin at 200 mg/d to limited quantities of supplemental concentrate for growing cattle grazing pastures. The pastures ranged from dormant end-of-the-season grasses and crop residues to lush green pastures, and were located in several different states. Pasture plus supplement supported gains of control cattle (without monensin) of .24 to .96 kg, with an average of .56 kg/d. The addition of 200 mg monensin to the supplement increased daily gain in all 24 trials by an average of .09 kg daily (+16.3%). Eleven trials were conducted with monensin and energy supplements fed at .907 kg.- head-1 X d-1 to growing cattle grazing growing, nondormant pastures for an average period of 117 d. Each trial was designed to compare the performance of unsupplemented cattle, cattle fed a supplement and cattle fed a supplement with monensin. Cattle on pasture gained .50 kg daily. Supplement feeding increased average daily gain by .09 kg and the addition of monensin to the supplement further increased gain by .09 kg, for a total increase of .18 kg (34.2%). The efficiencies with which supplemental feed was converted to extra gain (kg supplement/kg gain) for the supplement-only and the monensin treatment groups were 10.1:1 and 5.0:1, respectively. In a series of 12 trials, monensin was added at a level of 33 mg/kg air-dry diet to limited quantities of supplemental feed for cattle fed harvested forages in confinement. All trials compared monensin feeding with a nonmedicated control treatment. Hay was fed in 8 of the 12 trials, fresh-cut green-chop in two trials and ensiled corn stover and ensiled milo stover in one trial each. Monensin reduced feed intake by -3.1%, improved average daily gain by .09 kg (+14.4%) and improved feed efficiency by 15.3%.

Topics: Animal Feed; Animals; Body Weight; Cattle; Female; Furans; Male; Monensin

Two series of trials were conducted to evaluate alternative methods of administering monensin to pasture cattle. In a series of five trials, monensin was incorporated into supplements at 440 mg/kg to provide an average intake of 200 mg X head-1 X d-1 for growing cattle on pasture. Comparisons were made between daily and alternate-day feeding of the supplements. A control treatment consisting of unmedicated supplement fed daily also was included. Monensin at 200 mg/d and 400 mg on alternate days increased gain by .077 (P less than .01) and .082 (P less than .01) kg/d above control-cattle gains (.54 kg daily). Nine pasture trials were conducted to compare the effectiveness of monensin in increasing the daily gain of growing cattle when hand-fed daily in a supplement or self-fed in supplements that contained salt to regulate supplement intake. Desired supplement intakes were approximately .454 kg X head-1 X d-1 in six trials, .68 kg/d in one trial and 1.81 kg/d in two trials. Monensin produced gain increases of .09 kg daily (P less than .01) with both feeding systems. The daily gains of cattle that were hand-fed and self-fed were equal (P greater than .10). Self-fed treatments containing monensin required fewer changes in salt level than self-fed treatments not containing monensin, and the salt levels required to limit intake were generally 25 to 50% lower when monensin was in the supplement.

Topics: Animal Feed; Animals; Body Weight; Cattle; Female; Furans; Male; Monensin

In two feeding experiments fattening bulls received on average a daily supplement of 170 or 200 mg Monensin. In a further 8-week experiment the daily Monensin supplement was 0; 500 or 1 000 mg per day. Ergotropic Monensin supplements (experiments 1 and 2) did not change the blood count and the Ca, P and Mg content of blood serum and the activity of AP, AST and LAP in the serum remained unchanged. Net acid base excretion and the content of Na, K and Mg in urine were not significantly influenced either. The influence of 500 mg Monensin per animal and day on the feed intake of animals previously given lower supplements was insignificant. 1 000 mg Monensin per animal and day resulted in a 40% decrease of feed intake and permanent diarrhoea. It was connected with a diminishing of the glucose content in the blood and an increase of net acid base, Na and P excretion in urine. The blood count did not change after the Monensin overdose. In conclusion one can say that the ergotropic Monensin supplement did not change the metabolism parameters.

Topics: Animals; Blood Cell Count; Blood Chemical Analysis; Blood Gas Analysis; Blood Glucose; Body Weight; Cattle; Enzymes; Furans; Magnesium; Male; Monensin; Potassium; Rumen; Sodium; Vitamin A

A total of 180 male and 360 female day-old Indian River broiler breeder chicks were randomly allocated to 18 floor pens in an open-sided pullet brooding and growing house. The birds were subjected to six growing systems that were a combination of three levels of monensin (100, 300, and 400 ppm) and two levels of starter crude protein (CP) (14 and 18% CP) in a randomized complete block design. The basal diets were formulated to be isocaloric, containing 2920 kcal ME/kg. Birds fed 100 ppm of monensin were feed restricted and served as controls, while birds fed 300 or 400 ppm of the drug were fed ad libitum from day-old to sexual maturity. The parameters determined were biweekly individual body weights, feed consumption, internal organ weights, bone and serum mineral composition, and mortality to 21 weeks of age. In general, birds fed high levels of monensin plus ad libitum feeding from day-old were more variable in body weight compared to the feed-restricted controls. In the females, high levels of monensin in the diet were associated with significant reductions in body weight, even with ad libitum feeding, to 21 weeks of age. Male birds fed 300 ppm of the drug were significantly heavier than the feed-restricted controls but were still within the range recommended at this age. High levels of monensin in the diet were associated with a significant reduction in cumulative ad libitum feed consumption compared to the feed-restricted controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aging; Animals; Body Weight; Calcium; Chickens; Diet; Furans; Hematocrit; Magnesium; Monensin; Sexual Maturation; Sodium

Three experiments were conducted to evaluate the influence of several dietary factors on the monensin response in commercial broiler chicks fed corn-soybean meal diets varying in crude protein (CP). All experiments were conducted between 8 and 22 days posthatching. Trial 1 had a 2 X 2 X 2 factorial design wherein diets containing 16 or 24% CP and 0 or 121 mg/kg monensin were fed in the presence and absence of Eimeria acervulina infection. The monensin-induced growth depression was greater at 16% CP than at 24% CP. Coccidial infection had no effect on the monensin X protein level interaction. Monensin supplementation markedly improved performance of chicks infected with E. acervulina. Trial 2 was conducted to determine if the monensin-induced depression in performance caused by feeding a high level of monensin (140 mg/kg) could be moderated by feeding a high protein diet. Monensin supplementation reduced growth rate 18 and 10% in chicks fed 20 and 24% CP, respectively. Increasing CP to 28% alleviated the adverse effects of monensin on weight gain. Pair-feeding was used in Trial 3 to determine the extent to which the monensin-induced growth depression observed in chicks fed low protein diets was due to reduced feed intake. As expected, reducing the dietary CP from 24 to 16% resulted in a marked increase in the growth depression caused by 121 mg/kg monensin. Pair-feeding indicated that most of monensin's adverse effects in low protein diets could be attributed to its anorexic properties.

Topics: Animals; Body Weight; Chickens; Coccidiosis; Dietary Proteins; Feeding Behavior; Male; Monensin; Poultry Diseases

Five 7-day trials using 336, 24, 24, 40, and 40 Large White male turkeys when 7, 11, 15, 27, and 32 weeks of age, respectively, were conducted to determine the toxic effects of salinomycin. Salinomycin became more toxic as the age of the turkeys increased. When 7-week-old turkeys were fed diets containing 44 or 66 ppm salinomycin, only 1 of 84 died; when turkeys 27 or 32 weeks of age were fed those amounts, 13 of 20 died. Salinomycin at 22 ppm tended to depress rate of growth at young ages and to prevent or decrease growth and to increase mortality at older ages. Caution should be exercised to avoid salinomycin contamination of turkey diets.

Topics: Animals; Body Weight; Coccidiostats; Male; Monensin; Pyrans; Turkeys

Monensin in ruminant diets increases production of propionic acid. We have tested the hypothesis that propionic acid may be elevated to such an extent by monensin that it cannot be optimally metabolized by the methyl malonyl-CoA pathway requiring vitamin B12 (B12) in the liver. Thus, the effects of weekly B12 injections (10 mg X head-1 X wk-1, intramuscularly) with and without dietary monensin (25 mg/kg diet) on average daily gain (ADG), dry matter intake (DMI), feed to gain ration (F/G), liver and serum B12 concentrations and liver activity of propionate metabolizing enzymes were examined in an 84-d trial. Sixteen lambs (27.5 kg average initial wt) were assigned randomly to one of four treatments in a factorial arrangement: monensin plus B12, monensin without B12, no monensin plus B12 and no monensin without B12. Lambs were fed an 80% concentrate diet and slaughtered at the end of the trial. Liver samples were obtained by biopsy on d 0 and at slaughter on d 84 to determine activity of propionate metabolizing enzymes and B12 concentrations. Serum samples were taken on d 0, 28, 56 and 84 to determine serum B12 concentration. Neither monensin nor B12 affected (P greater than .10) ADG, DMI or F/G. Lambs receiving B12 had higher (P less than .01) serum B12 concentrations, but this was not reflected (P greater than .10) in higher liver B12 concentrations. No difference (P greater than .10) in liver propionate metabolizing activity among treatments was detected; however, monensin decreased (P less than .05) fumarate and malate formation by liver homogenates. Liver B12 concentrations were highly correlated with endogenous propionate metabolizing activity at d 0 (r = .73, P less than .01) and d 84 (r = .51, P less than .05). Results suggest no advantage to providing supplemental B12 to lambs fed monensin-supplemented, high-concentrate diets.

Topics: Animal Feed; Animals; Body Weight; Furans; Liver; Monensin; Propionates; Sheep; Vitamin B 12

Two, 7-week floor pen experiments were conducted consecutively with male broilers and then female broilers to determine the effects of feeding salinomycin (60 ppm), monensin (99 ppm), or lasalocid (125 ppm) at the following three levels of dietary protein: 1) that which meets National Research Council specifications (NRC, 1977), 2) that level deficient in sulfur amino acids (SAA), or 3) that deficient in protein. Group body weights, feed intake, and water consumption were noted at 28 and 49 days of age with feed efficiency and overall mortalities determined. Reducing SAA resulted in depressed (P less than .05) body weights at 7 weeks in both experiments, whereas deficient protein reduced (P less than .05) growth, feed efficiency, and water consumption. Generally, inclusion of coccidiostats in the diet did not significantly hinder growth or feed efficiency. Feeding of coccidiostats in combination with the low protein diet did not produce additional anorexigenic effects. Although a significant lasalocid SAA-sparing effect was not observed, diet X coccidiostat interactions (P less than .05) were apparent and attributable to an apparent "protein-sparing" effect upon body weight gain when salinomycin was fed in combination with the low protein diet. Lasalocid increased water consumption (P less than .05) relative to monensin in the female broilers.

Topics: Amino Acids, Sulfur; Animals; Body Weight; Chickens; Coccidiostats; Dietary Proteins; Drinking; Female; Food Additives; Lasalocid; Male; Monensin; Mortality; Pyrans; Sex Factors

Three experiments were conducted to examine the effect of monensin on growth performance, feed utilization and volatile fatty acids (VFA) in the forestomach and caecum of hamsters. In Expt 1, monensin was fed at levels of 0, 5, 10 and 20 mg/kg to the growing male and female hamsters given a commercial diet (major component: lucerne (Medicago sativa) meal). In Expt 2, monensin was fed at levels of 0, 5, 15, 45 and 135 mg/kg to the growing male hamsters given a semi-purified diet containing 10 g urea/kg (main components: maize starch, sucrose, casein and cellulose). In Expt 3, monensin was fed at levels of 0 and 40 mg/kg to the growing male hamsters given the commercial diet containing lucerne meal or a semi-purified diet. In Expt 1, monensin improved feed conversion efficiency and growth performances in the young growing hamsters, but monensin did not affect the hamsters at a later growing stage. In response to monensin the proportion of acetic acid increased and that of propionic acid decreased in the forestomach, whereas the proportion of acetic acid decreased and that of propionic acid increased in the caecum in Expt 2. The hamsters given 135 mg monensin/kg ate less, developed diarrhoea and died. The apparent digestibility of crude protein (nitrogen X 6.25) was improved by monensin but those of dry matter and neutral-detergent fibre (NDF) were decreased in hamsters given the semi-purified diet in Expt 3. Monensin did not appear to have a significant effect on the apparent digestibility of the diet containing lucerne meal. The responses to monensin in hamsters are compared with those in ruminants.

Topics: Animal Feed; Animals; Body Weight; Cricetinae; Digestion; Digestive System; Digestive System Physiological Phenomena; Fatty Acids, Volatile; Female; Fermentation; Furans; Male; Mesocricetus; Monensin

Fourteen trials were conducted to evaluate the effects of feeding monensin at 33 ppm alone, tylosin at 11 ppm alone and the two feed additives in combination on the average daily gain, average daily feed intake, feed:gain ratio and the incidence of liver abscesses in feedlot cattle. Monensin reduced feed intake and improved feed efficiency (P less than .05), and had no effect on average daily gain. Tylosin improved average daily gain (P less than .05) and had no effect on daily feed intake. The effect of tylosin on feed efficiency approached significance. The interaction of monensin and tylosin was nonsignificant for daily gain, daily feed intake and feed:gain ratio. Monensin had no effect on liver abscess incidence, while tylosin reduced abscess incidence from 27 to 9%.

Topics: Animal Feed; Animals; Body Weight; Cattle; Cattle Diseases; Feeding Behavior; Furans; Leucomycins; Liver Abscess; Monensin; Tylosin

Monensin was added at 0 or 23 mg/kg dry matter to low (8.3%) or high (17.5%) crude protein diets (2 X 2 factorial arrangement) that were fed to 28 growing wether goats for 194 to 256 d. Average daily gain increased 24% with monensin and 20% with higher crude protein (P less than .05). Feed conversion was improved by both monensin and higher crude protein (P less than .001). During the experiment, digestion and metabolism trials were conducted twice (Periods I and II) with each goat. Apparent dry matter and gross energy digestibility coefficients were not affected by monensin in either period. Digestibility of dietary N was enhanced 7% by monensin in Period II (P less than .01) and tended to be improved in Period I. Higher dietary protein increased all digestibility coefficients (P less than .001). Nitrogen retention was not affected by monensin but was greater (P less than .001) for high-protein-fed goats. Potential changes in empty body composition were assessed by comparative slaughter balance. No effects of dietary treatments on percentage composition of empty body were noted, except a trend for higher protein in monensin-fed goats compared with controls (P less than .1). Empty body protein gain as a percentage of protein intake improved 41% with monensin and decreased 37% with higher dietary protein content (P less than .05). Monensin increased conversion of dietary energy to body ether extract energy (12%, P less than .05), to protein energy (35%, P less than .001) and to total body energy (23%, P less than .001). Magnitude of improvement tended to be greater with low than high dietary protein treatments, suggesting a protein-sparing effect of monensin as determined by comparative slaughter method. However, N retention, measured by intake-excreta balances, was not affected by monensin, suggesting that these point estimates are less than adequate to evaluate true body protein gain.

Topics: Animals; Body Weight; Dietary Proteins; Furans; Goats; Male; Monensin

The rate of feather growth was measured in Hubbard X Hubbard broilers given monensin, salinomycin, or lasalocid for 8 weeks in floor pens. Chicks were given a nutritionally adequate diet. Feathers on male chicks were shorter at 10 days of age but grew faster than those on female chicks. Male chicks had longer feathers than female chicks after 31 days of age. Back feather scores were similar in male and female chicks at 52 days of age. Dietary ionophores had no effect on the rate of feather growth or the back feather coverage under the condition of this study.

Topics: Animals; Body Weight; Chickens; Coccidiostats; Feathers; Female; Food Additives; Lasalocid; Male; Monensin; Pyrans; Sex Factors

Three floor-pen trials have confirmed the high anticoccidial activity of CL 259,971 as first reported in batteries. The optimal dosage level was shown to be 5 ppm in the diet. At this level, excellent anticoccidial activity was observed with no adverse effect on weight or performance. The results indicated that 5 ppm of CL 259,971 provided efficacy and performance comparable to arprinocid or monensin, which were used for comparison in these trials.

Topics: Adenine; Animal Feed; Animals; Body Weight; Chickens; Coccidiosis; Coccidiostats; Energy Metabolism; Ethers; Female; Food Additives; Male; Monensin; Poultry Diseases

Newborn Holstein male calves were purchased within 3 days after birth and were removed from the local farms to the Dixon Springs Agricultural Research Center. They were hand-fed for 7 weeks and then weaned to a prepared feed. Eight groups, each of 4 calves, were housed in separate pens. In each of 4 pens (pens 2 to 5), 1 calf was inoculated with sporulated oocysts of Eimeria bovis (and was not medicated); 1 calf was inoculated and given feed with added monensin at the dosage level of 10 g/906 kg of feed; and 2 calves were inoculated and given medicated feed with added monensin at the dosage level of 20 g/906 kg or 30 g/906 kg. In the 4 other pens (6 to 9), the calves were inoculated with E zuernii and otherwise were given feed without or with added monensin as in pens 2 through 5. Another group of 5 calves (all kept in 1 pen), served as noninoculated, nonmedicated controls. At 14 days after inoculations with E bovis, the single calves in each of the 4 pens that were given the nonmedicated feed began to show clinical signs of coccidiosis and discharged increasing numbers of oocysts. The other inoculated calves (given monensin) had fewer clinical signs and discharged fewer oocysts in the feces as the level of medication in the feed increased. The calves inoculated with E zuernii developed only moderately severe infections when compared with those inoculated with E bovis. Inoculated (with E bovis) nonmedicated calves had severe reductions in feed consumption and weight, and 3 of 4 died.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Coccidiosis; Eating; Eimeria; Feces; Food Additives; Furans; Male; Monensin

In an individual feeding experiment (150-500 kg live weight) the influence of the polyether antibiotic Monensin on the fattening, slaughtering and retention performances of crossbreeding dairy bulls (genotype 31) and fattening hybrids (genotype 61) was ascertained. The supplementation of the polyether antibiotic on average resulted in a decrease by approximately equal to 11% of the dry matter and energy expenditure per kg weight gain due to a lower feed intake and a higher live weight gain. The slaughtering parameter investigated and the chemical composition of the empty body remained uninfluenced. The daily nutrient retention values were positively influenced by the Monensin supplementation since the fattening bulls of the test group required 30 days less to achieve the attempted fattening weight. The additional retention of protein, fat and energy per animal and day in the dairy bulls approximately equal to 10.9; 13.5 and 16.4% and in the fattening hybrids 1.9; 3.2 and 2.6%. Due to a higher energy retention at a lower level of feed and energy intake after Monensin supplementation an average of approximately equal to 11.3 and 15.4% resp. more of the consumed digestible protein and the digestible energy resp. were retained in the empty bodies. One can conclude that Monensin improved the utilisation of feed energy; obviously the effect of the polyether antibiotic is due to its influence on processes in the rumen or directly or indirectly on metabolism.

Topics: Animals; Body Weight; Cattle; Crosses, Genetic; Eating; Energy Metabolism; Food Additives; Furans; Male; Monensin; Proteins

Two short-term experiments were carried out with the polyether antibiotic monensin in East Ethiopia during the dry season. Monensin was given to 10 Boran Zebu bulls (84 days) and 15 female Ogaden sheep (112 days). All animals were grazing all day long on very poor rangeland. In the barn during the night, the animals were fed low concentrates, supplemented with 100 mg monensin per animal and day for bulls and 15 mg for sheep. The animals of the control croup did not receive any supplements. Monensin addition increased the daily weight gain of bulls from 15 to 89 g/animal (alpha greater than 0.05) and decreased the weight losses of the Ogaden sheep from 22 to 12 g/animal per day. The feed intake of grazing animals was not registered. Further experiments are recommended including more animals and longer experimental periods with antibiotics influencing the rumen fermentation to be carried out under tropical rangeland conditions.

Topics: Animal Feed; Animals; Body Weight; Cattle; Ethiopia; Female; Food Additives; Furans; Male; Monensin; Poaceae; Seasons; Sheep

The effects of several dietary factors on the anorexigenic response to monensin in chicks fed corn-soybean meal diets varying in crude protein (CP) were investigated. In Trial 1, crossbred chicks (New Hampshire X Columbia) were fed a 16% CP diet with or without 160 mg/kg monensin and/or .53% potassium carbonate in a 2 X 2 factorial design. Monensin supplementation caused a 24.5% growth depression, and potassium carbonate had no effect on the monensin-induced depression. Trials 2 and 3 were designed to evaluate the effects of dietary energy level on the monensin response in commercial broiler chicks fed diets containing 24, 20, or 16% CP. As CP level was decreased, the depression in performance from 121 mg/kg monensin increased. Increasing the energy concentration of the 24 and 20% CP diets to that of the 16% CP diet had no consistent effect on the response of chicks to monensin. Trial 4 was conducted to determine the influence of amino acid (AA) supplementation on the monensin response in broiler chicks fed a low-protein diet. Supplementation of a 16% CP diet with an AA mixture (3% glutamic acid plus essential AA equal to the 24% CP diet) improved growth performance markedly. Deletion of methionine, arginine, and lysine from the AA mixture yielded performance well below that of chicks fed the unsupplemented 16% CP diet, indicating a severe AA imbalance. Monensin supplementation at 121 mg/kg caused a much greater growth depression in chicks fed 16% CP or 16% CP plus the complete AA mixture than in those fed 24% CP or the AA-imbalanced 16% protein diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Amino Acids; Animals; Body Weight; Carbonates; Chickens; Dietary Proteins; Energy Intake; Food, Fortified; Furans; Male; Monensin; Potassium

Of 1,994 yearling and 2-year-old cattle in a winter feeding program, 117 died within 42 days of being fed toxic amounts of monensin sodium in a liquid protein supplement. Death losses commenced on the third day after ingestion of a toxic amount in the feed. Clinical signs in cattle that died in less than 9 days included anorexia, pica, diarrhea, depression, mild hindlimb ataxia, and dyspnea. Gross necropsy findings in cattle dying in the acute phase of the illness included hydrothorax, ascites, and pulmonary edema, as well as petechial hemorrhages, edema, and yellow streaking in skeletal and cardiac muscle. Cattle dying after 9 days had gray streaks in heart and skeletal muscle, generalized ventral edema, enlarged, firm, bluish discolored liver, and enlarged heart. Microscopic changes in cattle dying in the acute phase (less than 9 days) consisted of pulmonary edema, congestion, and hemorrhage. Cardiac and skeletal muscle had localized areas of edema, hemorrhage, and coagulative necrosis. In cattle dying after 9 days of illness, the changes included lymphocytic infiltration, sarcolemmal nuclear proliferation, and fibrosis in skeletal and cardiac muscle. Lungs contained increased alveolar macrophages and a few neutrophils. Centrilobular necrosis and mild fibrosis were found in the liver. Changes varied somewhat according to the area of heart or skeletal muscle that was affected. Active muscles, eg, those in the heart ventricles and diaphragm, were altered most severely. Intoxication appeared to be a result of sedimentation of monensin in the molasses carrier to give remarkable concentrations of the substance at the bottom of the holding tank.

Topics: Abortion, Veterinary; Animal Feed; Animals; Body Weight; Cattle; Cattle Diseases; Female; Furans; Liver; Lung; Male; Monensin; Muscles; Myocardium; Pregnancy

Five trials in five locations in the United States involving 512 steers were conducted to evaluate the effect of monensin [200 mg/d in .9 kg of supplement (Ru mensin )] and estradiol-controlled release implants ( Compudose ) administered alone and in combination on average daily gain (ADG) in steers on pasture. The effect of energy supplementation on rate of gain was also evaluated in these same trials. The initial weight of steers averaged 250 kg and the average duration of the five trials was 124 d. Estradiol-controlled release implants increased ADG by 15.6% (.095 kg/d; P less than .0001) and monensin increased ADG by 8.1% (.054 kg/d; P less than .05). The combination of estradiol-controlled release implant and monensin increased ADG by 27.4% (.168 kg/d). Treatment responses were additive relative to ADG response, with no interaction observed between the treatments. Nine-tenths kilograms of an energy supplement/d increased ADG by 12.4% (.073 kg/d; P less than .01).

Topics: Animals; Body Weight; Cattle; Drug Implants; Estradiol; Food Additives; Furans; Male; Monensin

Topics: Animals; Body Weight; Cattle; Digestion; Food Additives; Furans; Meat; Monensin

One hundred sixty-eight Angus X Hereford crossbred beef steers were utilized to evaluate the influence of two levels of monensin (0 or 33 ppm) on three levels of dietary protein (9, 11 or 13% on a dry matter basis). The study was divided into a growing phase when steers received ad libitum corn silage and the needed protein supplement to supply the appropriate protein level. The finishing diet consisted of 85% dry corn and 15% corn silage plus a protein supplement to yield an 11% protein diet fed to all steers. Estimates of carcass composition were made at the beginning, at the end of the growing phase and at completion of the study. During the growing phase, growth rate (GR), dry matter intake (DMI) and efficiency of gain (F/G) were all improved (P less than .01) with increasing protein level, while monensin reduced (P less than .01) DMI and improved (P less than .01) F/G, with the greatest improvement coming on the 9% protein diet. The rate of protein deposition was increased (P less than .05) with increasing protein level and was increased (P less than .01) on the 9% protein diet while being reduced on the 13% protein diet when monensin was included in the diet. Previous protein level influenced steer performance during the finishing phase, with the steers previously receiving the 13% protein diet having the poorest GR and F/G while those having received the 11% protein diet having the highest GR.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Composition; Body Weight; Cattle; Dietary Proteins; Food Additives; Furans; Male; Monensin

The polyether ionophore, laidlomycin, and several acyl derivatives were tested for their ability to favorably alter fermentation in two types of in vitro rumen fluid incubations. Dose response data were used to estimate the concentration (microgram/ml) of each ionophore required for either 50% maximal enhancement of propionic acid production (EC50) or 50% maximal inhibition of lactic acid production (IC50). Acylation of laidlomycin with straight-chain acyl groups from two to 12 carbon atoms tended to improve the potency of laidlomycin, especially for inhibiting lactic acid production. Comparative incubations using laidlomycin butyrate, laidlomycin and monensin indicated that both laidlomycin butyrate (EC50 = .3) and monensin (EC50 = .7) were more potent enhancers of propionic acid production than laidlomycin (EC50 = 2.0; P less than .05). Laidlomycin butyrate (IC50 = .3) was a more potent inhibitor of lactic acid production than either laidlomycin (IC50 = 1.8) or monensin (IC50 = 1.3; P less than .05). In a continuous culture experiment, three chemostats each received laidlomycin butyrate or monensin at the rate of .5 micrograms/ml of effluent/d while two flasks remained as control. Propionic acid production was increased (P less than .01) from 22.9 mmol/d in control flasks to 30.5 and 33.7 mmol/d in flasks treated with monensin and laidlomycin butyrate, respectively. Concomitant decreases in production rates of acetic, butyric and isovaleric acids also were observed (P less than .01). Thirty-six steers were used in a 56-d trial to evaluate effects of laidlomycin butyrate and monensin, at 33 mg/kg of diet, on feedlot performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Anti-Bacterial Agents; Body Weight; Cattle; Chemical Phenomena; Chemistry; Fatty Acids, Volatile; Female; Fermentation; Furans; Lactates; Lactic Acid; Male; Models, Biological; Monensin; Rumen

The effects of dietary protein source and monensin on growth performance of chicks fed diets containing 121 or 160 mg/kg monensin were investigated. Crossbred chicks (New Hampshire X Columbian) were fed a corn soybean meal diet (24% crude protein) containing 0, 5.0, or 13.0% animal-source protein supplied by various combinations of fish meal and meat and bone meal. Growth rate and gain/feed ratio were measured from 8 to 22 days posthatching. Growth performance was depressed by both 121 and 160 mg/kg monensin with the depression being greater at 160 mg/kg. The type or level of animal-source protein had no effect on the magnitude of growth depression caused by monensin. Growth performance was improved by addition of fish meal and meat and bone meal to the corn-soybean meal diet.

Topics: Animals; Body Weight; Chickens; Dietary Proteins; Food Additives; Furans; Male; Monensin

Six 300-kg steers were each fed a 70% cracked corn plus corn silage diet at two levels of intake above maintenance with and without 3 mg monensin/kg.75 body weight (W.75). A changeover design was used. Dietary energy and nitrogen were partitioned by duplicate, 22-h indirect respiration calorimetry measurements of heat and methane production on each animal concurrent with 7-d total feces and urine collection trials. Feed and feces were analyzed for energy, N, starch and neutral detergent fiber (NDF). The partial efficiency and(or) heat increment of metabolizable energy (ME) used for gain and maintenance was partitioned by regression of energy storage vs intake. At equalized gross energy intakes (adjustments made by covariance), monensin improved (P less than .01) the apparent digestibilities of energy, from 71.8 to 74.8%; NDF, from 50.5 to 57.5%, and crude protein, from 61.6 to 65.8%. Methane production averaged 5.7% of the control gross energy (GE), but was reduced by 26% (P less than .01) by monensin additions. Metabolizable energy was increased (P less than .01) from 63.3 to 66.8% of gross energy intake by monensin, resulting in an increase (P less than .01) in retained energy (64.7 to 72.3 kcal/W.75). Heat production was increased (P less than .05) by monensin, but only in proportion to the increased ME. Daily energy retentions adjusted to equal ME intake were similar with or without monensin (69.9 vs 67.1 kcal/W.75). No significant effects of monensin on the heat increment of ME use for maintenance or gain were observed. Both NEm and NEg were improved by approximately 7% by monensin; however, the relative effect on NEm vs NEg depends on method of calculation. At equalized GE intakes, approximately one-third of the improved energy utilization was explained by the reduced methanogenesis caused by monensin and two-thirds by reduced fecal losses.

Topics: Animals; Body Weight; Cattle; Diet; Digestion; Energy Metabolism; Food Additives; Furans; Male; Methane; Monensin; Silage; Zea mays

1. A procedure for measuring methane production by rumen contents incubated anaerobically in vitro is described. Assessments of methane production in vivo, in both sheep and cattle, were made by withdrawal of rumen contents and measuring their capacity to produce methane in vitro. 2. Many members of a series of 6-substituted 2,4-bis (trichloromethyl)-benzo[1,3]dioxins were potent inhibitors of methanogenesis by rumen contents in vitro. The most potent compound inhibited methane production by 70% or more at a concentration of 1 microgram/ml (approximately 2.5 mumol/l). 3. Two compounds, namely the 6-carboxylic acid (ICI 13409) and the 6-carboxamide (ICI 43586), caused a large inhibition of methanogenesis sustained for many hours, following a single intrarumen injection in sheep or cattle. Inhibition was maintained for long periods by single daily dosing directly into the rumen or by dietary administration. 4. In a 28-week growth trial in beef cattle inclusion of ICI 13409 in the concentrate element of the diet, at a level of 6 mg/kg body-weight, improved live-weight gain by 8.0% (P less than 0.05) with respect to untreated animals whilst reducing food intake by 5.0% (P less than 0.05). Smaller and not statistically-significant effects were seen with this compound at 3 mg/kg body-weight and with the antibiotic monensin (Romensin; Elanco PLC). All treatments significantly improved the retention of dietary energy into the carcass, offal and intestinal tracts of the trial animals and significantly reduced the quantity of methane eructed into expired gases.

Topics: Animals; Body Weight; Cattle; Diet; Dioxins; Male; Methane; Monensin; Rumen; Sheep; Time Factors

Five experiments were conducted with young, male, crossbred chicks to investigate the effects of experimental Eimeria acervulina infection on the efficacy of supplemental Cu and (or) methionine when added to a corn-soybean meal diet. Duodenal coccidiosis (due to E. acervulina) and supplemental Cu (500 and 750 mg/kg) depressed weight gain and efficiency of feed utilization. Supplemental Cu increased concentrations of Cu in liver and gallbladder; experimental coccidiosis resulted in a two- to fourfold increase in Cu deposition in these tissues compared with the respective controls. Excess supplemental methionine (.5%) had little effect on Cu toxicity in either healthy or infected chicks. Monensin, an ionophorous coccidiostat, alleviated the coccidiosis-induced Cu deposition.

Topics: Animal Feed; Animals; Body Weight; Chickens; Coccidiosis; Copper; Drug Interactions; Gallbladder; Liver; Male; Methionine; Monensin; Organ Size; Poultry Diseases

Monensin, lasalocid, salinomycin, nicarbazin, halofuginone, or arprinocid were fed to 1-week-old male broiler chicks at recommended levels and 1.5, 2, 2.5, and 3 times the recommended level, for 3 weeks. Pair-feeding experiments also were conducted to investigate the extent that growth depression with medicated diets could be attributed to the drop in feed consumption. At the recommended level of drugs, growth and feed conversion were not significantly affected. At elevated drug levels, performance was impaired; the adverse effects of drugs became more pronounced with increasing the concentrations in the diets. Weight gain was significantly depressed at 1.5X with arprinocid, halofuginone, and salinomycin, at 1 to 2X with monensin, at 2X with lasalocid, and at 2.5X with nicarbazin. Feed conversion, however, was adversely affected by 2X with halofuginone or 2.5X with salinomycin, nicarbazin, arprinocid, monensin, or lasalocid. The results of the pair-feeding experiments with 2 to 3 times drug levels indicated that most of the growth depression with medicated diets could be attributed to reduced feed consumption, but all drugs except arprinocid caused some additional growth depression.

Topics: Adenine; Animal Feed; Animals; Body Weight; Chickens; Coccidiostats; Growth; Lasalocid; Male; Monensin; Nicarbazin; Piperidines; Quinazolines; Quinazolinones

1. Diets containing 80, 100, 125, 150, 175 or 200 mg monensin/kg were fed to broiler chickens from 0 to 28 d in cages that prevented access to excreta. 2. Growth was depressed with 125 mg monensin or more/kg and food intake tended to decrease. Feathering was adversely affected with 175 mg or more/kg. 3. In a similar experiment, diets containing 8.8, 9.1, 9.4, 9.7 and 10.1 g total sulphur amino acids (SAA)/kg were supplemented with 125 or 80 mg monensin/kg and compared with a diet containing 8.8 g SAA and 33 mg robenidie/kg. 4. With 125 mg monensin/kg, body-weight gain was significantly less than that of birds receiving robenidine if dietary SAA content was 9.4 g or less/kg. With 9.7 g SAA or more/kg, gain in birds receiving monensin was similar to that of birds receiving robenidine. 5. Monensin at 125 mg/kg therefore appears to increase SAA requirement.

Topics: Amino Acids, Sulfur; Animals; Body Weight; Chickens; Feathers; Female; Food Additives; Furans; Male; Monensin; Nutritional Requirements; Robenidine

Chickens were given concentrations of monensin in the feed which increased at weekly intervals (60 to 121 ppm). This resulted in a fairly constant intake of drug (mg/k body weight). Such chickens consumed less drug than those given monensin at 121 ppm. Chickens given variable concentrations of drug in the food were well protected against coccidiosis judged by the parameters of lesion scores and mortality. Total body weight of these chickens was greater and lesion scores at 28 days were lower compared with chickens given constant levels of monensin, but the differences were not significant. These results suggest that adequate control of coccidiosis in broilers could be achieved by administering a relatively low concentration of an anticoccidial 0 to 3 weeks followed by a high concentration.

Topics: Administration, Oral; Animal Feed; Animals; Body Weight; Chickens; Coccidiosis; Furans; Male; Monensin; Poultry Diseases

A 23 factorial arrangement of treatments was utilized to determine the effect of breed, creep feeding and monensin on subsequent reproductive performance and lactation of 32 primiparous heifers. One-half of each breed (Angus and Hereford) group had access to creep feed (2.67 Mcal metabolizable energy/kg) while nursing their dams. Approximately 40 d before breeding through 120 d of lactation, all heifers were fed a suboptimal energy diet and 50% of each breed and creep group received 200 mg monensin/head daily. Estrus was synchronized with a progestogen. Volatile fatty acids (VFA) were determined periodically throughout the monensin-feeding portion of the experiment. Twenty-four hour milk production, percentage butterfat and percentage solids-not-fat were determined at 60 and 120 d postpartum. Weaning weights (adjusted to 205 d and for age of dam) of the original heifers were heavier (P less than .05) for those that were creep fed compared with those not creep fed (219 vs 202 kg). Monensin-supplemented females gained significantly more weight from the initiation of treatment to immediately postcalving and gave birth to heavier calves (P less than .05) even though they received comparable amounts of dietary energy as those that did not receive monensin. The energy stressed, monensin-supplemented first-calf heifers exhibited a shorter postpartum interval (P less than .05) to first estrus than did those that did not receive monensin (55.7 vs 69.1 d, respectively). First-calf heifers that had been creep fed while nursing their dams had a lower (P less than .05) daily milk yield at 120 d post-partum than those that did not have access to creep feed. No detrimental effects were observed due to long-term monensin supplementation.

Topics: Animals; Birth Weight; Body Weight; Cattle; Diet; Female; Furans; Lactation; Monensin; Pregnancy; Pregnancy, Animal; Reproduction

An experiment was designed to determine the effects of dietary monensin on age and weight at puberty in Bos taurus crossbred beef heifers. One hundred and forty heifers were allotted to two weight classes: heavy (H) and light (L) groups, consisting of heifers above and below the average weaning weight, respectively. Heifers within each weight class were assigned to one of three diets during a 203-d winter feeding period: (1) R, 80% roughage: 20% concentrate; (2) M1, R diet plus monensin (200 mg/head daily) with feed intake restricted to produce average daily gains (ADG) similar to R and (3) M2, R diet plus monensin (200 mg/head daily). ADG was higher (P less than .001) for M2 heifers than for R and M1 heifers, which performed similarly. Age and weight at puberty were similar across treatments in L heifers. However, in the H group, HM1 and HM2 heifers were younger (P less than .07) at puberty than HR heifers and this difference was not removed by covariate adjustment of either ADG or body weight. Weigh at puberty was greater (P less than .01) for HM2 heifers than for HM1 or HR heifers; however, this difference was removed by covariate adjustment of either ADG or body weight. Ninety-one percent of LM2 heifers and 100% of all other groups had reached puberty before the breeding season. Pregnancy rates did not differ significantly between treatment groups. Supplementation of a high roughage diet with monensin decreased age at puberty of heifers in the heavy weight class and this decrease was not due to increased body weight or ADG. Perhaps heifers with above average weaning weight possess a greater inherent growth potential than heifers below the average weaning weight and hence are more capable of utilizing monensin to an advantage.

Topics: Acetates; Acetic Acid; Aging; Analysis of Variance; Animals; Body Weight; Butyrates; Butyric Acid; Cattle; Fatty Acids, Volatile; Female; Fertility; Furans; Monensin; Propionates; Rumen; Sexual Maturation

Sixty Holstein heifers initially weighing 196 kg were assigned by weight to treatments of 0, 200, and 600 mg of monensin. These treatments were fed daily until calving to determine effects of monensin on growth rate, feed consumption, feed efficiency, reproductive performance, and subsequent lactation. Throughout the feeding period the control (0 mg) heifers received sufficient feed to allow a calculated growth rate of .68 kg/day. Monensin treatment groups were fed the same amount of the identical ration over the 448-day experiment. Daily gain, feed intake, and feed efficiency for the 0, 200, and 600 mg treatments were .60, .69, .69 kg, 7.47, 7.46, 7.43 kg, and 12.41, 10.81, 10.81. Although days on trial to first estrus were not different among treatment groups, heifers fed monensin at 200 and 600 mg/day conceived 38 and 34 days sooner than 0 mg heifers. Percent conception, number of calves born, calf birth weight, and calving difficulty were not affected by treatment. Milk production was measured for 120 days subsequent to the experimental feeding of monensin. During this period heifers were fed a common ration ad libitum. Milk production of 17.1, 16.9, and 17.0 kg/day for 0, 200, and 600 mg was not affected by prior treatment.

Topics: Animals; Body Weight; Cattle; Diet; Estrus; Female; Furans; Lactation; Monensin; Pregnancy; Pregnancy, Animal; Reproduction; Time Factors

Four experiments were conducted to investigate a possible interaction between dietary protein level and monensin on growth performance of young chicks. Crossbred chicks (New Hampshire X Columbian) or commercial broiler chicks (Hubbard X Hubbard) were fed corn-soybean meal diets containing various protein levels with or without added monensin (160 or 121 mg/kg). Monensin had little or no effect on growth performance of crossbred chicks fed diets containing 24 or 20% protein. However, growth performance of chicks fed 16% protein diets was depressed 15 and 8% by 160 and 121 mg/kg monensin, respectively. With commercial broiler chicks a marked interaction was observed between dietary protein level and monensin. As dietary protein level decreased, the depression in performance from monensin increased. At 24.0, 21.5, 19.0, and 16.5% protein, weight gains at 4 weeks of age were depressed 20, 29, 35, and 45% by 160 mg/kg monensin and 7, 14, 19, and 28% by 121 mg/kg monensin, respectively. Linear regression analysis indicated that 121 mg/kg monensin depressed growth rate an additional 2.7% for each 1% reduction in dietary protein level. A large portion of the growth depression from monensin could be explained by reduced feed intake. The results of this study indicate that level of dietary protein has a profound effect on the magnitude of growth depression caused by addition of monensin to chick diets. Thus, deficient levels of dietary protein should be avoided when using this anticoccidial drug in broiler feeds.

Topics: Animal Feed; Animals; Body Weight; Chickens; Dietary Proteins; Drug Interactions; Food Additives; Furans; Male; Monensin

Topics: Animals; Anti-Bacterial Agents; Body Weight; Chickens; Diterpenes; Drug Interactions; Drug Tolerance; Electrolytes; Feeding Behavior; Furans; Monensin

The effects of monensin or ruminal fermentation, forage intake and weight gains of stocker cattle grazed on wheat pasture were studied. In the first of two ruminal fermentation studies, ruminal fluid pH was increased and total volatile fatty acid (VFA) concentrations at 4 (p less than .01) and 24 hr postfeeding were decreased in steers fed 200 mg monensin/day. However, no such changes in ruminal fluid pH and total VFA concentrations in monensin-fed steers were observed in trial 2. The ruminal fluid acetic to propionic acid ratio of steers that received monensin was decreased (P less than 0.5) by about 40 and 20% of trials 1 and 2, respectively. Results of two forage intake trials, in which steers received 0 or 200 mg monensin daily, were not consistent, precluding conclusions about the effect of monensin, per se, on stocking rate adjustments when the additive is used in wheat pasture stocker programs. In each of two growth trials, conducted over 2 years, about 125 heifers per year were divided into three groups: one group grazed wheat pasture and received no supplement, and the other two grazed wheat pasture and were fed a pelleted supplement that contained 0 or 100 mg monesin. Daily gains of heifers fed monensin were .08 kg greater (p less than .01) than those fed supplement without monensin. The data indicate that monesin does have potential for use in wheat pasture stocker programs.

Topics: Animal Feed; Animals; Body Weight; Cattle; Eating; Fermentation; Furans; Male; Monensin; Rumen; Triticum

Early weaned male crossbred lambs (n = 90) with an average weight of 14 kg were used in 6 groups to evaluate the efficacy of monensin (22 mg/g of feed) and lasalocid (12.5, 25, 50, and 100 mg/kg of feed) on naturally occurring coccidiosis. Average 24-hour oocyst output at the start of the experiment ranged from 5.7 x 10(6) to 156.7 x 10(6) for monensin-treated and 100-mg lasalocid-treated groups, respectively. Monensin and lasalocid were effective against Eimeria ninakohlyakimovae of E ahsata. To day 103, body weight gains were similar for the 4 groups fed lasalocid (336 g/day) and averaged 6% higher (P greater than 0.05) than did gains in control and monensin-treated lambs. Feed efficacy averaged 9% higher (P less than 0.05) for lambs fed 25, 50, and 100 mg of lasalocid/kg of feed and 7% higher (P greater than 0.05) for lambs fed monensin and 12.5 mg of lasalocid/kg of feed. There were no treatment effects on digestibility, although lasalocid tended to increase (P greater than 0.05) crude protein digestibility (values were higher on day 76 than on day 28). Lasalocid and monensin were potent manipulators of rumen fermentation. Increasing the amount of lasalocid in the feed was associated with successive increases (P less than 0.05) in molar proportions of propionic acid and decreases (P less than 0.05) in acetic acid. Lasalocid and monensin controlled naturally occurring coccidiosis and improved performance in early weaned lambs (45 days old) under feedlot conditions.

Topics: Administration, Oral; Animal Feed; Animals; Body Weight; Coccidiosis; Fatty Acids, Volatile; Fermentation; Furans; Lasalocid; Monensin; Rumen; Sheep; Sheep Diseases

The influence of the polyether antibiotic Monensin on the rumen fermentation and the fattening results of fattening hybrids (genotype 61) and crossbreeding bulls of dairy cattle (genotype 19) was ascertained in two feeding experiments (E1 and E2). Caused by the supplementation of the antibiotic, the molar acetate quota decreased (1.9 to 4.8 Mol %) and the molar propionate concentration increased (0.2 to 2.9 Mol %) in the rumen fluid of crossbreeding bulls of dairy cattle and of fattening hybrids, it is, however, below the range described in literature. With the exception of the fattening hybrids in E1, the supplementation of Monensin resulted in the diminished intake of dry matter, the daily increase of the live weight of all groups of fattening bulls was higher (E1: fattening hybrids: 1106 resp. 1199g; crossbreeding bulls of dairy cattle: 1037 resp. 1058 g; E2: 997 resp. 1024 g; 895 resp. 981 g without resp. with Monensin). After the Monensin supplementation the crossbreeding bulls of dairy cattle showed a distinctly bigger decrease of the feed intake and a rise of the live weight increase than the fattening hybrids. For this reason the genotypes of dairy cattle showed in both experiments after the Monensin supplementation a bigger decrease of expenditure (0.8 resp. 7.1% and 5.6 resp. 11.3% in experiments 1 and 2) than the fattening hybrids.

Topics: Animals; Body Weight; Cattle; Crosses, Genetic; Female; Fermentation; Furans; Genotype; Male; Monensin; Rumen

One growth and two finishing trials were conducted with beef steers to compare lasalocid sodium and monensin sodium. Pure lasalocid, mycelia-cake lasalocid and monensin, each added individually to commercial protein supplement blocks at 880 mg/kg, depressed (P greater than .05) block intake so that approximately 100 mg of each additive were consumed daily by each animal. Daily gain, feed intake and feed efficiency for steers receiving blocks containing additives did not differ from the corresponding measures for steers receiving control blocks. No differences were observed in diet dry matter digestibility, as determined with acid-insoluble ash as an internal marker. Both forms of lasalocid and monensin reduced (P greater than .05) the incidence and concentration of coccidia oocysts. By day 40, only one steer on each of the additive treatments was shedding oocysts (4.2% of additive-supplemented animals), compared with 41.5% of the control steers. During trial 2, steers fed pure lasalocid gained faster and more efficiently (P greater than .05) than those fed the mycelia-cake lasalocid, monensin or control diets. The improvement in feed efficiency over the control value was 10.0, 3.4 and 4.0% with pure lasalocid, mycelia-cake lasalocid and monensin, respectively (P greater than .05). Steers fed mycelia-cake lasalocid had higher (P greater than .05) dressing percentages than those fed pure lasalocid or monensin. Dressing percentage was the only carcass measurement affected. In trial 3, lasalocid at 30 and 45 g/ton and monensin at 30 g/ton improved (P greater than .05) feed efficiency by 7.5, 11.0 and 8.2%, respectively. No significant differences in incidence or concentration of oocysts were observed between treatment groups in trial 3, probably because steers were in slatted floor pens.

Topics: Animal Feed; Animals; Body Weight; Cattle; Cattle Diseases; Coccidia; Coccidiosis; Feces; Food Additives; Furans; Lasalocid; Male; Monensin; Parasite Egg Count

A study on mineral metabolism and conversion of nutrients by applying sodium monensinate, 125 mg per head and day, in cattle fattening was performed. This experiment was realized under production conditions in the fattening station of pavillion type for 367 days and included 985 bulls of Bohemian Spotted cattle. The feed ration consisted of maize silage with addition of dried poultry bedding and concentrates. At the beginning of the experiment the appetite antipathy was observed, the adaptation period lasted 4 weeks. During the adaptation period the weight gains decreased; after adaptation of animals to monensin the weight gain not only counter-poised, but in comparison with the control it increased. Throughout the experiment no health disorders connected with the applied additive were observed. In the rumen fluid the content of calcium, magnesium, phosphorus, zinc, copper and iron was followed. In the blood plasma the levels of sodium, potassium, calcium, magnesium, phosphorus, zinc, copper and iron were followed. The application of sodium monensinate did not affect the followed parameters of mineral metabolism. The experiment was aimed at the evaluation of production and operational parameters with a view to the weight gain and feed conversion. In the experimental group the weight gain was higher by 3.85%. The saving of maize silage in the experimental group amounted to 5.8%, by using of this additive the saving of concentrates amounted to 1.35%. In the experimental group the feed conversion converted to dry matter increased by 7.12%. Sodium monensinate at the dose of 125 mg per head and day had positive effect on the followed production and economic parameters.

Topics: Animals; Body Weight; Cattle; Food Additives; Furans; Minerals; Monensin; Rumen

Monensin fed to beef cows at levels of 50, 200 or 300 mg daily during late gestation and early lactation induced feed savings of 3.2, 10.5 and 13.5%, respectively, when feed intakes were regulated to produce similar changes in cow weights, condition scores and weight to height ratios during the 168-day feeding period. Feed dry matter intakes were different (P < .05) for the orthogonal single degree of freedom comparisons that were made. The monensin treatments and the adjustments in feed intake associated with them had no apparent effect on (1) calf birth weights, (2) adjusted 205-day weaning weights or (3) first-service conception rates for the cows. Monensin increased (P < .05) the proportion of propionate and the ratio of acetate to propionate in rumen samples taken prepartum, but not in samples taken postpartum. Blood samples obtained at the same time that rumen samples were obtained showed no treatment effects on serum creatinine, lactic dehydrogenase, alkaline phosphatase, inorganic phosphorus, calcium, creatine phosphokinase, glutamic-pyruvic transaminase or total protein.

Topics: Animals; Body Weight; Cattle; Eating; Female; Furans; Monensin; Pregnancy; Pregnancy, Animal; Reproduction

Three polyether, ionophorous anticoccidial drugs were fed to broiler chickens in floor pens for 5 or 6 weeks, then withdrawn for 2 weeks or 1 week, respectively. With monensin and salinomycin there was evidence of increased feed consumption and compensatory growth during the first week, but not the second week, after drug withdrawal. There was no evidence of compensatory growth in birds fed lasalocid. Final weights were best in birds fed lasalocid and salinomycin in comparison with unmedicated controls and birds fed monensin. There was evidence of increased feed consumption and compensatory growth in some treatments in which birds weighed more than controls prior to drug withdrawal.

Topics: Animals; Antibodies; Body Weight; Chickens; Eating; Furans; Ionophores; Lasalocid; Monensin; Pyrans

A corn-soybean (CS) diet and diets containing medium or high levels of animal protein (AP) calculated to contain the same concentrations of the main nutrients promoted essentially the same growth rate and feed utilization in 20-day-old chicks. Supplementation with monensin sodium (100 or 120 mg/kg) depressed growth rate of the chicks fed all three diets. However, effect of the drug was much more severe in chicks fed the diets containing AP. This interaction resulted in significant (P < .05) differences in body weights between chicks fed the CS diet and PA diets. Moreover, feed-to-gain ratio was significantly (P < .05) adversely affected by monensin only in chicks fed the AP diets. Supplementation of the high AP diet with extra vitamin E, a mixture of arginine and tryptophan, or a mixture of silicon, chromium, and molybdenum failed to prevent the growth depression caused by monensin. These studies demonstrate that ingredient composition of diets for broiler chicks affects the magnitude of growth depression caused by monensin supplementation.

Topics: Animals; Body Weight; Chickens; Diet; Furans; Monensin

Two trials were conducted to determine the influence of monensin on live weight gain and efficiency of forage utilization of calves grazing Bermudagrass. In trial 1, 32 calves, weaned at an average age of 238 days and 250 kg, were grazed on "Coastcross I" Bermudagrass from July 20 to October 13. Eight steers and eight heifers were randomly assigned to one of two treatments: 200 mg monensin/head/day or 0 mg monensin/head/day fed in a .01 kg/head/day diet of pelletized 14% protein feed. Both groups were stocked at 15.3 head/ha. Monensin-fed calves gained .52 kg/head/day, while the control-fed calves gained .42 kg/head/day (P < .10). Average daily gains (ADG) of steers (.54 kg) were greater (P < .05) than those of heifers (.40 kg). Forage to gain ratio estimates were 15:1 and 19:1 for calves on monensin and control paddocks, respectively. In trial 2, 48 steer calves, averaging 265 days of age and 260 kg, were randomly assigned to each of two replicates of the following grazing treatments: common Bermudagrass only (P), Bermudagrass + .91 kg/head/day 14% protein feed (PF) or Bermudagrass + .91 kg/head/day feed + 200 mg monensin/head/day (PFM). ADG were .45, .47 and .68 kg for steers fed P, PF and PFM, respectively. The monensin-fed calves showed a 45% improvement in ADG (P < .05). Estimated forage to gain ratios for calves fed P, PF and PFM were 20:5:1, 19:1 and 13:1, respectively. The use of 200 mg monensin/head/day improved calf gains by 23 to 45% and increased estimated feed efficiencies by 21 to 36% on Bermudagrass pastures. The improvement in gain for heifers fed monensin was 28.6%, while steers gained 18.4% more when fed monensin.

Topics: Animal Feed; Animals; Body Weight; Cattle; Female; Furans; Male; Monensin; Poaceae

One-hundred and fifty crossbred yearling-heifers, averaging 264 +/- 17 kg were fed a 77% barley diet for 140 days to evaluate the effect of 0, 33, 49.5 and 66 ppm avoparcin and 33 ppm monensin on growth rate, feed efficiency, carcass quality and ruminal volatile fatty acid (VFA) concentration. Heifers were allotted by weight to 25 pens (six head per pen) in a randomized complete block design of five treatments and five replicates per treatment. On day 140, rumen fluid was obtained from a randomly selected replicate of six heifers from each treatment for VFA analysis. Carcass data and liver samples were obtained at slaughter on day 147. All avoparcin-fed cattle consumed less feed per unit gain (P less than .05) than did those in the control group. Feed intakes of the monensin-fed heifers and the heifers fed 49.5 ppm avoparcin were lower (P less than .05) than those of the control group. There were no differences (P greater than .05) between treatments for measured carcass, liver or rumen parameters.

Topics: Animals; Anti-Bacterial Agents; Body Weight; Cattle; Fatty Acids, Volatile; Female; Furans; Glycopeptides; Monensin

Lasalocid and monensin were incorporated into pelleted feed and evaluated as anticoccidials in confinement-reared lambs from weaning to market weight. A total of 69 lambs were allotted to 3 equal groups that received unmedicated feed (100 mg/kg of food) or monensin-medicated feed (17 to 33 mg/kg). Each lamb was inoculated orally with a suspension of 24,000 oocysts (Eimeria spp) 24 and 52 days after the start of the experiment. Lasalocid and monensin were highly effective (greater than 99%) in eliminating oocysts of 5 species of ovine coccidia used in the inoculum. Treated lambs gained an average of 6 kg more weight (P less than 0.05) per animal than the untreated control lambs and consumed significantly (P less than 0.05) less feed for each kilogram gained. No statistical differences existed between treated groups (P greater than 0.05).

Topics: Animals; Anti-Bacterial Agents; Body Weight; Coccidiosis; Feces; Lasalocid; Monensin; Sheep; Sheep Diseases

Topics: Ammonia; Amprolium; Animal Feed; Animals; Body Weight; Coccidiosis; Digestion; Fatty Acids, Volatile; Feces; Female; Furans; Male; Monensin; Picolines; Rumen; Sheep; Sheep Diseases

Lasalocid was tested at graded feed concentrations in controlled battery experiments against single and mixed Eimeria species infections in 2-week-old turykey poults. Eimeria meleagrimitis, E. gallopavonis, E. adenoeides, and E. dispersa infected poults medicated with lasalocid at concentrations of 0.15, .0125, .01, .0075, and .005% were heavier, converted feed more efficiently, showed lower lesion scores (ADI), shed fewer oocysts, and showed reduced or no mortality as compared to the infected, unmedicated controls. Lasalocid activity was similar against the few field isolates tested. Lasalocid responses were dose related, the higher the concentration, the greater the effect. The optimum dose level in these battery studies was approximately .0125%. Lasalocid fed at two times the optimum dose level to poults for a four week period did not have any adverse effect on growth or feed conversion performance.

Topics: Animals; Body Weight; Coccidiosis; Lasalocid; Monensin; Poultry Diseases; Turkeys

Lambs naturally infected with mixed species of Eimeria were fed monensin (30 mg/kg of feed) and aureomycin (10 mg/kg of feed) separately and in combination. An evaluation was made of the efficacy of the treatments in the suppression of oocyst production. Comparisons were made of the parasitic damage to the intestinal surface. Performance of the lambs was measured by weight gains and feed efficiency. Monensin given separately or in combination with aureomycin produced decreases in oocyst counts that were not significantly different from those in the lambs given only aureomycin. Body weight gains and feed efficiency were best in the aureomycin-treated group, and less so in the monensin-treated and the control groups. Animals fed the monensin-aureomycin combination had the poorest weight gains and feed efficiency. Scanning electron microscopy indicated that the groups fed monensin or aureomycin separately had morphologically normal intestinal surfaces. This was in contrast to the control group and the group fed the monensin-aureomycin combination, wherein there was disrupted intestinal surface morphology.

Topics: Animals; Body Weight; Chlortetracycline; Coccidiosis; Coccidiostats; Drug Combinations; Furans; Monensin; Sheep; Sheep Diseases

Topics: Animal Nutritional Physiological Phenomena; Animals; Body Weight; Cattle; Diet; Fatty Acids, Volatile; Female; Fermentation; Monensin; Rumen; Sexual Maturation

Sixteen female and 16 male lambs were used in 4 groups to determine the effect of monensin on naturally occurring and experimentally induced coccidiosis. Determinations of numbers of oocysts discharged, quantities of feces discharged, feed consumption, and weight gain were made for female and male lambs in each group. The effect of experimentally induced and naturally occurring coccidiosis on the performance of each group was compared. Nonmedicated lambs, experimentally inoculated with Eimeria ninakohlyakimovae, gained the least weight. Lambs naturally infected with coccidia gained next best and inoculated lambs, in 2 groups medicated with 10 or 20 ppm of monensin in the feed, gained best. The average net gain for the 4 groups was 7.8, 9.7, 13.7, and 13.7 kg. The medicated lambs required less feed/kilogram of weight gain than did the nonmedicated lambs. In general, female lambs were more severely affected by the coccidia, consumed more feed, produced more fecal material, and gained less weight than did male lambs.

Topics: Animal Feed; Animals; Body Weight; Coccidiosis; Feces; Female; Furans; Male; Monensin; Sheep; Sheep Diseases

Including 120 to 250 mg./kg. additional copper in practical broiler rations significantly affected the cecal appearance. The ceca were distended and the contents were darker in color and more pasty in consistency, compared to controls. Adding monensin sodium, gentian violet, or ferrous sulfate alone or in combination with copper to the ration did not significantly change the appearance of the ceca. Copper concentrations in the cecal contents reached levels above 5000 mg./kg., suggesting that the mechanism of action of copper in changing the appearance of the ceca may be related to an inhibition of normal fermentation that occurs in this part of the gastrointestinal tract. Sulfate, chloride and carbonate forms of copper all significantly changed cecal appearance, but the oxide did not, nor did a non-copper containing sulfate source. Macroscopic appearance of the gizzard lining and the proventriculus was also significantly changed by adding 240 mg./kg. copper to the diet, and liver weight and lipid content of liver dry matter were significantly increased.

Topics: Animals; Body Weight; Carbonates; Cecum; Chickens; Chlorides; Copper; Gizzard, Avian; Iron; Monensin; Proventriculus; Sulfates

Lonomycin (TM-481, SQ 12,525) at various concentrations in the feed was tested in controlled battery experiments against laboratory strains of single and mixed Eimeria species infections. The experimental results indicated that lonomycin at doses of .003125, .00625, or .0125% demonstrated a high degree of anticoccidial activity by preventing or reducing mortality, reducing fecal dropping scores, and allowing for normal or near-normal weight gains against single and mixed infections of 5 major pathogenic species, E. acervulina, E. brunetti, E. maxima, E. necatrix, and E. tenella. Lonomycin, at these same dosages, was highly effective against a recent field isolate obtained from a flock previously fed monensin. These studies involving 7 trials totaling 1,680 broiler chicks, have demonstrated that lonomycin at levels of .003125 to .0125% (dependent on species of Eimeria) in the feed is an effective aid in the control of avian coccidiosis in broiler chickens.

Topics: Administration, Oral; Animal Feed; Animals; Anti-Bacterial Agents; Body Weight; Chickens; Coccidiosis; Coccidiostats; Ethers; Female; Lasalocid; Male; Monensin; Nigericin; Poultry Diseases

Infections with single species of Eimeria acervulina, E. mivati, E. maxima, E. tenella, E. necatrix, and E. brunetti, and the six species mixed, were utilized in three separate battery experiments to evaluate the anticoccidial efficacy of various levels of salinomycin (AHR-3096), a fermentation product of a strain of Streptomyces albus. At the 60 to 100 p.p.m. treatment levels, this compound showed significant anticoccidial activity for all parameters studied (mortality, weight gain, feed conversion, dropping scores, and lesion scores). The mortality due to coccidiosis was reduced to 0.1% in the medicated infected birds. Some activity, as measured by weight gain, was seen in the lower levels of salinomycin medication (12.5 to 50 p.p.m.), but other parameters, including mortality and lesion scores, indicated less activity than that seen with the higher treatment levels. At 100 p.p.m., there was no apparent effect on the compound on bird performance in uninfected control birds. Salinomycin at the 100 p.p.m. treatment level was statistically as effective as 121 p.p.m. monensin (reference anticoccidial) in controlling coccidiosis.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Body Weight; Chickens; Coccidiosis; Coccidiostats; Intestines; Monensin; Poultry Diseases; Pyrans

Three experiments determined if the methionine requirement of broiler chicks was affected by coccidial infection. Chicks were fed a corn-soy or a corn-soy-pea basal diet containing 0.73% and 0.62% total sulfur amino acids (TSAA), respectively. Levels of 0 to 0.45% DL-methionine were added, with and without 0.01% monensin sodium. In two experiments, the chicks were inoculated at two weeks of age with a mixture of oocysts of E. acervulina, E. maxima, E. tenella, E. necatrix and E. brunetti. Lesion scores on the intestines and ceca, and blood carotenoid levels were determined at three weeks. The experiments were terminated at four weeks. A level of methionine greater than 0.47% and of TSAA greater than 0.83% was necessary to obtain maximum growth rate in uninoculated chicks. No evidence of dermatitis was observed. Growth rate and feed efficiency of chicks infected with coccidiosis were more severly depressed when the diet was not supplemented with methionine. Infections of coccidia and low levels of methionine, which in themselves did not produce any significant change in weight gain, did give a significant weight depression in combination. Adding monensin to the diet prevented a reduction in growth rate and feed efficiency of inoculated chicks fed adequate methionine. Monensin did not completely prevent the adverse effects of a coccidial infection, based on feed efficiency, when chicks were fed diets inadequate in methionine. Blood carotenoid levels were not affected by methionine level, but were significantly lowered by coccidial infection in the absence of monensin. Intestinal and cecal lesions in inoculated chicks were significantly reduced by including monesin in the diet. Although the coccidial infection more severly affected the performance of chicks fed diets deficient in methionine, satistical analysis of pooled data indicated no difference in the quantitative requirement of chicks for methionine. Therefore, a level of methionine and cystine adequate for optimum growth under the coccidial-free conditions should be adequate for chicks when infected with coccidia.

Topics: Animals; Body Weight; Carotenoids; Chickens; Coccidiosis; Cystine; Methionine; Monensin; Poultry Diseases

The feed level of monensin which gave maximal protection from coccidial infection in broilers reared in floor pens depended on the severity of the coccidial exposure and the criteria of infection studied. With indirect seeding of pens with coccidia (light coccidial exposure), 40 ppm was as efficacious as 100 ppm in improving weight gain, lesion score, and feed conversion. Statistical analysis with direct seeding (seeder birds; severe coccidial exposure) showed that feed levels of 84 and 102 ppm gave maximal improvement of weight gain and 4-week feed conversion, respectively. Further increasing the monensin level from 100 to 121 ppm did not improve weight gain and feed conversion at 8 weeks. Conversely, the relationship of plasma pigmentation and total lesion scores to monensin feed levels indicated that increasing the dosage of monensin from 100 to 121 ppm improved the performance of the broilers on the basis of these 2 infection indicators.

Topics: Administration, Oral; Animal Feed; Animals; Body Weight; Carotenoids; Chickens; Coccidiosis; Female; Furans; Male; Monensin; Poultry Diseases; Skin Pigmentation

Monensin was effective within the range 60-100 p.p.m. in control of coccidiosis in turkey poults in a series of laboratory experiments. Under conditions of heavy infections with Eimeria meleagrimitis and E. adenoides, 100 p.p.m. of monesin was significantly more effective than 60 p.p.m. in protecting weight gains. When light or moderate infections with E. meleagrimitis, E. adenoides and E. gallopavonis were used, there were no significant differences among monesin-medicated treatments. In all instances the monensin-medicated treatments gained significantly more weight than noninfected, nonmedicated controls, when measured at 7 days post-inoculation. Similarly, oocyst, passage was reduced, feed conversion was protected and mortality was controlled in monensin-treated poults.

Topics: Animals; Body Weight; Coccidiosis; Feces; Furans; Monensin; Poultry Diseases; Turkeys

Thirty crossbred ewe lambs weighing an average of 37.3 kg were allotted to 6 groups of 5 lambs each so that group weights were nearly equal. Lambs were fed dehydrated alfalfa pellets, initially at 1.14 kg/day and subsequently increased after experimental day 15 and 42. Each lamb was artificially infected with 18,000 sporulated oocysts of Eimeria ninakohlyakimovae. Groups 1, 2, 3, and 4 were given monensin in the form of medicated alfalfa pellets at dose levels of 5, 10, 20, and 30 g/metric ton, respectively. Groups 5 and 6 were infected controls (infected, nonmedicated). Lambs in groups 5 and 6 developed severe clinical coccidiosis, having diarrhea and losing weight rapidly. Group 1 lambs did not have diarrhea, but the lambs did not gain well. All other medicated lambs gained weight during the experimental period of 84 days. Feed conversion was good in medicated groups 2, 3, and 4 and was poor in control groups 5 and 6. Statistically significant differences in feed conversion and body weight gains (5 and 1% level of confidence) were observed between control and medicated groups.

Topics: Animal Feed; Animals; Body Weight; Coccidiosis; Female; Furans; Monensin; Sheep; Sheep Diseases