virginiamycin and Body-Weight

We evaluated the effect of feed additives on the risk of ruminal acidosis in Holstein heifers (n = 40) fed starch and fructose in a challenge study. Heifers were randomly allocated to feed additive groups (n = 8 heifers/group): (1) control (no additives); (2) virginiamycin (VM); (3) monensin + tylosin (MT); (4) monensin + live yeast (MLY); and (5) sodium bicarbonate + magnesium oxide (BUF). Heifers were fed 2.5% of body weight (BW) dry matter intake (DMI) per day of a total mixed ration (62:38 forage:concentrate) and feed additives for a 20-d adaptation period. Fructose (0.1% of BW/d) was included for the last 10d of the adaptation period. On d 21, heifers were fed to target a DMI of 1.0% of BW of wheat, fructose at 0.2% of BW, and their feed additives. Rumen fluid samples obtained by stomach tube and blood samples were collected weekly as well as during a 3.6-h period on challenge day (d 21). Virginiamycin and BUF groups maintained a consistently high DMI across the 20-d adaptation period. The MLY heifers had low DMI of the challenge ration. Average daily gain and feed conversion ratio were not affected by feed additives. All rumen and plasma measures changed weekly over adaptation and over the challenge sampling period with the exception of rumen total lactate and histamine concentrations, plasma oxidative stress index, and ceruloplasmin. Substantial within- and between-group variation was observed in rumen and plasma profiles at challenge sampling. No significant group changes were observed in rumen total volatile fatty acids, propionate, acetate-to-propionate ratio, isobutyrate, caproate, isovalerate, total lactate, d- and l-lactate, and pH measures on challenge day. Acetate concentration was increased in the BUF and control groups on challenge day. Butyrate concentration was lower in the MLY and MT groups compared with other groups at challenge. Valerate concentrations were lowest in the control, VM, and BUF groups and lactate concentrations were numerically lower in the MLY, VM, and BUF groups. Total lactate concentrations were >10mM for each group throughout the challenge. Ammonia concentrations were lower in the MLY and MT groups. Histamine concentrations were decreased in MLY and increased in the VM and BUF groups. Plasma oxidative stress measures were not influenced by feed additives weekly or on challenge day, except for an increase in biological antioxidant potential in the control, VM, and MT groups on challenge day. Despite the large within-

Topics: Ammonia; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Body Weight; Cattle; Diet; Fatty Acids, Volatile; Female; Fermentation; Fructose; Hydrogen-Ion Concentration; Lactic Acid; Rumen; Starch; Virginiamycin

1. A total of 720 female broiler chicks was used to test the effects of 4 dietary concentrations of a Chinese herbal medicine (CHM) formulation (0.25, 0.5, 1 and 2g/kg), as an alternative for virginiamycin (VRG), on growth performance in broilers. 2. A total of 72 birds from non-supplemented, VRG and 0.5 g/kg CHM groups was selected and killed and the relative weights of the intestinal segments were assessed. 3. The CHM dietary treatments produced increased body weight gain at 7 to 21 d of age but not at 21 to 28 d of age compared with the non-supplemented and VRG groups. The CHM groups had a higher feed intake and a higher feed conversion ratio (FCR) than the VRG group between 21 and 28 d. 4. The dissection results showed that the liver colour of the birds in the CHM group varied less between animals than that of the VRG and the non-supplemented groups. Neither CHM nor VRG had any significant effects on either liver or intestinal tract weights. 5. It was concluded that the birds of the CHM group had better growth performance from d 7 to 21 but not thereafter. Further experiments are needed to elucidate the mechanisms underlying enhanced growth performance by CHM in broilers.

Topics: Animals; Anti-Bacterial Agents; Body Weight; Chickens; Drugs, Chinese Herbal; Eating; Female; Intestines; Liver; Organ Size; Virginiamycin

Male broiler chicks were fed diets containing 0 or 3.5 mg aflatoxin (AF)/kg from 1 to 28 d of age. The diets were amended with either .5% hydrated sodium calcium aluminosilicate (HSCAS), 16.5 mg virginiamycin (VM)/kg of diet, or .5% HSCAS + 16.5 mg VM/kg of diet to determine the effects of these compounds during aflatoxicosis. When compared with controls (814 g), BW gains were significantly lower for broilers fed the AF (731 g) or AF+VM (716 g) diets. No differences were found between the BW gains of chicks fed diets without aflatoxin (814 g) and those of chicks fed AF+HSCAS (793 g) or AF+HSCAS+VM (803 g), indicating approximately 75% protection against decreased BW gain by HSCAS and 87% protection by the HSCAS+VM combination. Relative weights of the liver and kidney and creatine kinase activity were significantly increased and albumin, total protein, cholesterol, uric acid, and inorganic phosphorus concentrations were decreased in chicks fed the diet containing AF alone. With the exception of albumin, HSCAS was effective in restoring these values to control values. The findings of this research suggest that HSCAS and HSCAS+VM can counteract some of the toxic effects of AF in growing broiler chicks.

Topics: Aluminum Silicates; Animals; Body Weight; Chickens; Drug Therapy, Combination; Male; Mycotoxicosis; Organ Size; Poultry Diseases; Treatment Outcome; Virginiamycin

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

A study was conducted to evaluate the effects of mannanoligosaccharides (MOS), bambermycins (BAM), and virginiamycin (VIR) on the growth performance of male turkeys. Hybrid Large White male poults were assigned to six dietary treatments: control, MOS, BAM, VIR, MOS+BAM (MB), and MOS+VIR (MV). All diets were formulated to meet NRC (1994) nutrient requirements. There were eight replicate floor pens per treatment with 20 birds per pen reared from 1 to 140 d. Body weight and feed conversion (FC) were collected at 3-wk intervals and at 20 wk of age. Mortality and culled birds were recorded daily. All treatments except MV significantly (P < 0.05) increased 20 wk BW. Body weight was increased at 12 wk by BAM, whereas VIR increased BW at Weeks 12 and 15. All treatments improved FC for Weeks 0 to 3, whereas VIR, MB, and MV improved FC for Weeks 0 to 12 and 0 to 18. There were no treatment effects on cumulative mortality or cull rate. Dietary supplemental MOS, BAM, and VIR resulted in improved growth performance of Large White turkeys. These results indicate that MOS may be utilized as an alternative to antibiotic growth promotants to improve turkey performance.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Bambermycins; Body Weight; Dietary Supplements; Energy Metabolism; Male; Mannose; Oligosaccharides; Random Allocation; Turkeys; Virginiamycin; Weight Gain

Two experiments were conducted to evaluate the effect of virginiamycin (VM, 22 mg/kg of diet) on performance of uninfected (CON) turkey poults and those infected (INO) with stunting syndrome and reared on used woodshavings (Experiment 1) or on clean or used woodshavings (Experiment 2). Virginiamycin improved BW (P less than .001) and feed efficiency (FE) (P less than .05) from 1 to 29 days of age, irrespective of type of litter or disease condition. The increase in BW induced by VM, however, was greatest when poults were kept on used litter, resulting in significant (P less than .05) VM by litter interaction. Induced stunting syndrome depressed BW (P less than .01) to 29 days of age and impaired FE from 1 to 9 days of age (P less than .05) and from 5 to 9 days of age (P less than .01) in Experiments 1 and 2, respectively. Virginiamycin did not prevent early adverse effects of INO on BW and FE, but facilitated notable recovery of INO poults relative to INO poults not fed VM. Virginiamycin increased specific activities of maltase and sucrase of the jejunum of CON poults in Experiments 1 and 2; in Experiment 2, this VM effect was evident irrespective of type of litter. Maltase-specific activity and sucrase were reduced by INO (P less than or equal to .05 and P less than or equal to .01 in Experiments 1 and 2, respectively) and VM did not modify this effect. The maltase and sucrase data suggest that VM improved BW and FE of CON poults, in part, by helping to maintain digestive and absorptive functions of the small intestine during the early growth period, but, in the instance of INO poults, VM was not effective in this regard.

Topics: alpha-Glucosidases; Animals; Body Weight; Digestion; Enteritis; Growth Disorders; Jejunum; Male; Poultry Diseases; Sucrase; Syndrome; Turkeys; Virginiamycin

Two replicate trials, each involving 400 Arbor Acre male broiler chicks, were conducted to determine the effect of virginiamycin as a growth promoter when added to either the feed or drinking water. A control group received no growth promoter while one treatment group was provided a diet containing 11 mg of virginiamycin/kg. Another treatment group was provided drinking water containing virginiamycin in amounts calculated to ensure equivalent or one-half equivalent intake of the antibiotic. Virginiamycin supplementation had no significant (P greater than .05) effect on mortality or feed conversion ratios, regardless of the mode of administration. Body weights at 21 days of age but not at 42 days of age were significantly (P less than .05) heavier for broilers receiving virginiamycin via the drinking water. The inclusion of virginiamycin in the feed failed to improve body weights at either 21 or 42 days of age.

Topics: Animal Feed; Animals; Body Weight; Chickens; Drinking; Drug Residues; Food Additives; Growth Substances; Male; Random Allocation; Virginiamycin

Broilers were grown to 49 days of age on diets supplemented with bambermycins (BAM, 2.2 ppm), bacitracin methylene disalicylate (BMD, 27.5 ppm), virginiamycin (VM, 11 ppm), or an unmedicated control. Samples of birds were processed for dressing percentage and parts yield. There were no significant (P greater than .05) effects of antibiotics on final body weight, feed conversion, or mortality. In male broilers, BMD and VM significantly (P less than or equal to .05) increased dressing percentage and percentage yield and reduced the skeletal rack as a percentage of postchill weight compared to those fed the nonmedicated control. All antibiotics significantly increased breast skin weight and breast skin as a percentage of postchill weight of as compared with those fed the unmedicated control. In female broilers, BAM and BMD significantly increased dressing percentage and percentage yield and increased breast weight and breast as percentage of postchill weight as compared with those fed the unmedicated control diet. Females fed BMD also had significantly heavier leg quarters and breast skin than those fed the unmediated control. Females fed VM had increased breast skin weight and breast skin as a percentage of postchill weight than those fed the unmedicated control. The results of the present study indicate that antibiotics may influence dressing percentage and parts yield in the absence of improvements in body weight gain or feed utilization.

Topics: Analysis of Variance; Animals; Bacitracin; Bambermycins; Body Weight; Chickens; Female; Male; Organ Size; Virginiamycin

Two trials were conducted with 32 and 39 finishing Belgian white-red bulls, treated with anabolic agents during 55 to 60 days prior to slaughter. Xenobiotic androgens and estrogens, together with (Exp. I) or without progesterone (Exp. II) were injected at three-week intervals. Diets consisted of maize silage and 7.5 g concentrate daily per kg liveweight. Half of the animals within each experiment received an antibiotic for the entire fattening period lasting about 285 days. Lasalocid-sodium (Exp. I) and virginiamycin (Exp. II) were incorporated at 65 mg per kg concentrate. Anabolic agents improved average daily gain from 1.06 to 1.20 kg (P less than 0.10) and from 1.24 to 1.42 kg (P less than 0.05) respectively. In both trials steroidal growth promoters stimulated intake and improved feed efficiency (P less than 0.10). Feed antibiotics did not significantly affect daily gain during this short term finishing period. A reduced feed intake (P less than 0.05) and improved feed conversion were observed for lasalocid, while there was no difference for virginiamycin. Dry matter intake amounted to 80.5 and 76.3 g per kg metabolic weight and 9.02 and 8.41 kg per kg gain, respectively for control and lasalocid treated animals. The data were 79.6 and 80.3 g and 7.30 and 7.34 kg, respectively, for the experiment with virginiamycin. No significant interaction between anabolics and antibiotics was obtained with respect to gain and feed efficiency. Dressing percentage, carcass composition, carcass grading and meat traits were not affected by anabolic treatment or antibiotic supplementation.

Topics: Anabolic Agents; Androgens; Animal Feed; Animals; Body Weight; Cattle; Eating; Estrogens; Lasalocid; Male; Meat; Medroxyprogesterone; Medroxyprogesterone Acetate; Virginiamycin

An experiment was conducted to determine the effect of dietary Virginiamycin on processing yields of broilers fed four levels of energy. Body weights (catch, slaughter) and carcass weights (dry shell and ready-to-cook) were recorded. Shrink (holding weight loss), water uptake, shell yield, and ready-to-cook yield of the carcasses were calculated. Body weights were higher at higher energy levels and with addition of Virginiamycin to the diets. Weight loss due to shrink declined from 5.39 to 3.89% at higher dietary energy levels, but shrink was not affected by Virginiamycin. Water uptake was significantly higher for carcasses of birds fed the lowest dietary energy level (3.49%) than for carcasses of birds fed the two highest energy levels (2.89 and 3.03%); but differences among water uptake of carcasses of birds fed the three highest energy levels were not significant. Water uptake was unaffected by Virginiamycin. Increasing the dietary energy level resulted in higher ready-to-cook yields, from 61.7% yield at 2,271 kcal ME/kg to 65.4% yield at 2,953 kcal ME/kg. Yield was increased from 63.3 to 64.0% (P less than .01) by dietary Virginiamycin.

Topics: Animals; Body Weight; Chickens; Diet; Energy Metabolism; Virginiamycin

An experiment was conducted with broiler chicks to determine the influence of Virginiamycin on chicks fed diets with four levels of energy. Addition of the Virginiamycin to the diet resulted in significantly improved body weight and feed efficiency at all levels of energy. The greatest improvement was obtained at the lowest level of energy. Addition of Virginiamycin to the diet decreased the energy required to produce a unit of body weight.

Topics: Animals; Body Weight; Chickens; Diet; Energy Metabolism; Virginiamycin

Two experiments, each consisting of two trials, were conducted with day-old Nicholas Large White turkey poults to compare the effectiveness of four antibiotics for growth promotion and the utilization of sulfur amino acids. A corn-soybean meal basal diet that contained no supplemental methionine, choline, or inorganic sulfate was used in order to furnish nutritional stress. The diet was calculated to contain 25.4% protein, .448% methionine, .403% cystine, 1014 mg/kg choline, and 2990 kcal metabolizable energy/kg. In Experiment 1, a 2 X 4 factorial arrangement of treatments was used. This included two levels, (0% (control) and .18%), of supplemental DL-methionine and no antibiotic or bacitracin MD, flavomycin, or virginiamycin; antibiotics were fed at 50, 2, and 20 g/ton, respectively. In Experiment 2, lincomycin also was included as a treatment (at 4 g per ton) resulting in a 2 X 5 factorial arrangement of treatments. Only the addition of Virginiamycin to the control diet in Experiment 1 resulted in significantly increased body weights. Supplementation by .18% methionine increased body weights and feed efficiency. In addition, all three antibiotics increased body weights significantly when added to the .18% methionine diets. Feed efficiency values were improved by all four antibiotics at both methionine levels. In Experiment 2, increases in body weights similar to those in Experiment 1 were obtained with the addition of .18% methionine to the basal diets. Addition of lincomycin and virginiamycin improved body weights and feed efficiencies in the presence and absence of supplemental methionine.

Topics: Animals; Anti-Bacterial Agents; Bacitracin; Bambermycins; Body Weight; Lincomycin; Methionine; Turkeys; Virginiamycin

Two experiments were conducted for five 28-day periods each. In Experiments 1 and 2, Hyline W-36 hens, 36 and 26 weeks of age, respectively, were used. Experiment 1 was designed to measure the effect of virginiamycin on hen performance and egg characteristics when supplementing a diet having low pigmentation potential. In Experiment 2, the diet contained 3% added fat with 0, 10, and 20 ppm virginiamycin. In Experiment 1, virginiamycin-supplemented hens showed increased (P less than or equal to .05) egg production, body weight, and improved feed efficiency. When egg production and feed efficiency were ranked by quartiles within the control and virginiamycin-supplemented groups, virginiamycin was shown to benefit only the poorer producing hens. In Experiment 2, added fat improved feed efficiency; however, the response to virginiamycin, as observed in Experiment 1, did not occur.

Topics: Animals; Body Weight; Chickens; Egg Yolk; Female; Food Additives; Mortality; Oviposition; Pigmentation; Virginiamycin

The effect of growth-stimulating agents (15 ppm of virginiamycin, 10 ppm of avoparcin and 12 ppm of nitrovin) and that of seven days' treatment with 300 ppm of furazolidone on the performance of broilers was studied in an experimental study of 9,600 animals. Furazolidone was fed in either the fourth or the fifth week of life and combined with virginiamycin or nitrovin. Non-significant improvements in growth were observed when virginiamycin (1.5 per cent), avoparcin (0.7 per cent) and nitrovin (0.7 per cent) were administered. Treatment with furazolidone for seven days resulted in substantial retardation of growth. When broilers were treated during the fourth week of life, the retardation of growth was largely compensated for during the other two weeks. Treatment in the fifth week of life resulted in lower weights prior to slaughter. Therefore, care should be taken in recommending treatment with furazolidone at the end of the fattening period of broilers.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Body Weight; Chickens; Food Additives; Furazolidone; Glycopeptides; Growth Substances; Nitrovin; Virginiamycin

An experiment was conducted with day-old Cobb feather-sexed chicks to determine the influence of virginiamycin on phosphorus. When the average of the three levels of phosphorus were combined, utilization, body weights, and bone ash at 21-days of age were improved by the addition of virginiamycin to the diet. Also the amount of phosphorus required to produce a gram of body weight was decreased by the addition of virginiamycin to the diet.

Topics: Animals; Body Weight; Calcium Phosphates; Chickens; Female; Food Additives; Food, Fortified; Male; Phosphorus; Virginiamycin

An experiment was conducted with day-old turkey poults to study the influence of virginiamycin on energy utilization. A 2 X 2 factorial arrangement of treatments was used, which included ad libitum or a 25% feed restriction and 0 or 22 ppm of virginiamycin. Virginiamycin in the diet significantly improved body weight, feed efficiency, and dietary energy utilization when poults were fed ad libitum or when feed was restricted. These data indicate that virginiamycin enhances the utilization of dietary energy by turkey poults.

Topics: Animals; Body Weight; Eating; Energy Metabolism; Female; Food Additives; Male; Turkeys; Virginiamycin

Five hundred forty crossbred pigs were utilized in four trials (10 replications) at two stations to determine the separate and interacting effects of decreasing floor space allowance with or without the addition of virginiamycin to the diet on performance of growing-finishing pigs. Pigs were allowed .37, .33 or .28 m2/pig during the growing phase (23 to 55 kg) and .74, .66, .56 m2/pig during the finishing phase (55 to 100 kg) and fed either a corn-soybean meal control diet or the control diet plus 11 mg of virginiamycin/kg of diet. Floor space allowances were achieved by varying pen size, so the number of pigs and feeder space per pig were constant for all pens. During the growing phase, daily gain (P less than .01) daily feed intake (P less than .05) and feed conversion ratio (P less than .05) decreased as floor space allowance decreased. During the finishing phase and for the total test period, daily gain (P less than .01) and feed conversion ratio (P less than .05) were reduced but daily feed intake was not affected (P greater than .05) by restricted floor space allowance. The addition of virginiamycin to the diet had no effect on pig performance. The virginiamycin X floor space allowance interaction was not significant, suggesting that pigs fed a diet with or without virginiamycin responded similarly to restricted floor space allowance. The data suggest that the addition of virginiamycin to the diet was ineffective in overcoming the decrease in performance of growing-finishing pigs caused by crowded conditions.

Topics: Animal Feed; Animals; Body Weight; Crowding; Eating; Energy Metabolism; Food Additives; Housing, Animal; Swine; Virginiamycin

Three balance trials, each involving 12 crossbred gilts averaging 35.2 kg body weight, were conducted to determine the effects of dietary fiber and virginiamycin on nutrient digestibility, mineral absorption and retention, and digesta rate of passage (RP). Two levels of fiber (13.5 and 20.2% neutral detergent fiber) and two levels of virginiamycin (0 and 11 ppm) were used in a 2 X 2 factorial arrangement of treatments. All diets were isonitrogenous and isocaloric. The RP was determined by observing the time required for a change in feces color after the addition of .5% chromic oxide to the diet. The high fiber diet had a faster (P less than .01) RP, which was associated with depressions (P less than .001) in the digestibility of dry matter (DM), energy (E), cell contents, neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HC), cellulose, permanganate lignin and ash. Virginiamycin supplementation slowed (P less than .004) the RP of both low and high fiber diets, but improved (P less than .05) the DM, E, NDF, ADF, HC and cellulose digestibility of the high fiber diet only. Fiber increased (P less than .06) fecal N excretion, whereas virginiamycin supplementation decreased (P less than .08) fecal N excretion. The addition of virginiamycin improved the absorption and retention of P, Ca, Mg, Cu, Fe, Zn and Mn when added to the high fiber diet, but had little or no effect when added to the low fiber diet even though absorption and retention values for most minerals were similar or slightly higher for the unsupplemented high fiber diet compared with the unsupplemented low fiber diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Weight; Dietary Fiber; Digestion; Energy Metabolism; Feces; Female; Food Additives; Intestinal Absorption; Minerals; Nitrogen; Swine; Virginiamycin

Topics: Animals; Anti-Bacterial Agents; Body Weight; Female; Food Additives; Male; Pyrans; Swine; Virginiamycin

Two experiments were conducted with broilers to determine the effect of Virginiamycin supplementation on performance and shank pigmentation. Virginiamycin supplementation at 10 ppm resulted in significantly increased body weights in both experiments. Feed efficiency was significantly improved in Experiment 1 by the supplementation of 5 and 10 ppm Virginiamycin. In Experiment 2, 20 ppm Virginiamycin was included and resulted in no greater response than that observed at 10 ppm. Pigmentation values as measured by a reflectance colorimeter and Roche color fan favored (P less than or equal to .05) Virginiamycin supplementation in both experiments. Data indicated that when the diet was supplemented with Virginiamycin an increase in the utilization of xanthophyll resulted. Mortality was not influenced by dietary treatment.

Topics: Animals; Anti-Bacterial Agents; Body Weight; Chickens; Female; Food Additives; Lutein; Male; Pigmentation; Virginiamycin

Two experiments were conducted with day-old Nicholas Large White turkey poults. A 2 x 3 factorial arrangement of treatments was used in Experiment 1 (0 and 22 ppm of virginiamycin and 0, .06, and .12% supplemental DL-methionine). A 2 x 4 factorial arrangement of treatments was used in Experiment 2 (0 and 22 ppm of virginiamycin and 0, .04, .08, and .12% DL-methionine). A corn-soybean meal diet was used that contained no supplemental choline and a sulfate-free trace mineral mix. The experiments were conducted for 21 days. Body weight was increased by virginiamycin and by all levels of supplemental methionine. However, feed efficiency was not influenced.

Topics: Animals; Body Weight; Diet; Food Additives; Methionine; Stereoisomerism; Turkeys; Virginiamycin

Topics: Animals; Body Weight; Carbadox; Feeding Behavior; Food Additives; Pyrans; Swine; Virginiamycin

Three trials were conducted with 252 pigs to determine the effects of the dietary additions of Cu (250 ppm as copper sulfate), with and without sulfide (500 ppm as ferrous sulfide), and antibiotics (55 ppm chlortetracycline or 27.5 ppm virginiamycin) on the performance and liver Cu stores of growing-finishing pigs. Single additions of Cu, chlortetracycline or virginiamycin to a 16% protein, corn-soybean meal-based diet improved daily gains by 4.0, 4.2 and 3.4% and feed to gain ratios by .3, 2.9, and 1.3%, respectively, in comparison with those of pigs fed the control diet. The addition of ferrous sulfide to the high Cu diets reduced liver Cu stores from 278 to 21 ppm, a level approaching that of the control pigs, and increased the growth response to supplemental Cu by 4.0%. The inclusion of both Cu and an antibiotic in the diet in the in the absence or presence of sulfide resulted in daily gains in feed to gain ratios similar to those of pigs receiving a single antimicrobial agent. These data suggest that the growth-promoting effects of Cu and chlortetracycline or Cu and virginiamycin are not additive in the growing-finishing pig allowed to consume feed ad libitum.

Topics: Animals; Body Weight; Chlortetracycline; Copper; Ferrous Compounds; Iron; Sulfides; Swine; Virginiamycin

Topics: Animals; Body Weight; Diet; Dysentery; Swine; Swine Diseases; Virginiamycin

Topics: Animals; Body Weight; Diet; Female; Lysine; Male; Swine; Virginiamycin

Five trials involving 518 pigs were conducted to determine the effects of the dietary addition of copper (0 or 250 ppm as copper sulfate) with and without antibiotics (55 ppm chlortetracycline, CTC, or 27.5 ppm virginiamycin VIR) on the rate and efficiency of gain and survival of early-weaned pigs. The experimental animals consisted of all pigs weaned from each of 67 litters at 28 +/- 2 days of age, regardless of weight or condition. In trials 1 through 4, single additions of copper, CTC or VIR to the corn-soybean meal-based diet improved (P less than .05) daily gains by 22, 22 and 17%, respectively, and feed to gain ratios by 5.1, 8.9 and 8.2% compared with those of pigs fed the unsupplemented diet during the 28-day trials. However, only the addition of copper to the diet increased (P less than .05) postweaning pig survival. Dietary inclusion of both copper and an antibiotic (CTC or VIR) further improved daily gains (P less than .05) by 10 to 11% and feed to gain ratios by 2 to 5% compared with the single addition of each antimicrobial agent. In trial 5, 125 ppm of copper were found to optimize daily gain and feed intake, whereas 250 ppm were required to maximize pig survival. These data demonstrate that high levels (125 to 250 ppm) of dietary copper increase the growth rate and reduce the incidence of mortality among weanling pigs. The data also indicate that the growth-promoting effects of copper and CTC, a broad spectrum antibiotic, or VIR, a gram-positive antibiotic, are additive in nature.

Topics: Animals; Animals, Newborn; Body Weight; Chlortetracycline; Copper; Eating; Swine; Virginiamycin

Topics: Animals; Body Weight; Diet; Female; Fertility; Fetus; Growth; Organ Size; Ovary; Ovulation; Placenta; Pregnancy; Rabbits; Uterus; Virginiamycin

Topics: Animal Feed; Animals; Body Weight; Female; Growth; Intestine, Small; Liver; Male; Organ Size; Rabbits; Virginiamycin

Topics: Aniline Compounds; Animal Feed; Animals; Anti-Bacterial Agents; Arsenicals; Bacitracin; Body Weight; Chickens; Food Additives; Intestine, Small; Nitrofurans; Nitrophenols; Organ Size; Seasons; Virginiamycin

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Body Weight; Cecum; Diet; Intestine, Small; Liver; Organ Size; Rabbits; Stomach; Virginiamycin

Topics: Animals; Anti-Bacterial Agents; Arginine; Bacitracin; Body Weight; Cecum; Dose-Response Relationship, Drug; Feeding Behavior; Female; Galactose; Glucose; Histidine; In Vitro Techniques; Intestinal Absorption; Intestinal Mucosa; Intestine, Small; Male; Mice; Mice, Inbred Strains; Organ Size; Virginiamycin