oxytetracycline--anhydrous and Weight-Gain

Oral treatment with antimicrobials is widely used in pig production for the control of gastrointestinal infections. Lawsonia intracellularis (LI) causes enteritis in pigs older than six weeks of age and is commonly treated with antimicrobials. The objective of this study was to evaluate the efficacy of three oral dosage regimens (5, 10 and 20mg/kg body weight) of oxytetracycline (OTC) in drinking water over a five-day period on diarrhoea, faecal shedding of LI and average daily weight gain (ADG). A randomised clinical trial was carried out in four Danish pig herds. In total, 539 animals from 37 batches of nursery pigs were included in the study. The dosage regimens were randomly allocated to each batch and initiated at presence of assumed LI-related diarrhoea. In general, all OTC doses used for the treatment of LI infection resulted in reduced diarrhoea and LI shedding after treatment. Treatment with a low dose of 5mg/kg OTC per kg body weight, however, tended to cause more watery faeces and resulted in higher odds of pigs shedding LI above detection level when compared to medium and high doses (with odds ratios of 5.5 and 8.4, respectively). No association was found between the dose of OTC and the ADG. In conclusion, a dose of 5mg OTC per kg body weight was adequate for reducing the high-level LI shedding associated with enteropathy, but a dose of 10mg OTC per kg body weight was necessary to obtain a maximum reduction in LI shedding.

Topics: Administration, Oral; Animals; Anti-Bacterial Agents; Bacterial Shedding; Desulfovibrionaceae Infections; Diarrhea; Dose-Response Relationship, Drug; Feces; Female; Lawsonia Bacteria; Male; Oxytetracycline; Swine; Swine Diseases; Weight Gain

Antimicrobial consumption in animal husbandry is of great scientific and political concern due to the risk of selection of resistant bacteria. Whilst a reduction in the use of antimicrobials is therefore preferable, the efficacy of treatment must be maintained in order to ensure animal welfare and profitability of pig production. The objective of this study was to evaluate the efficacy of three treatment strategies under field conditions against Lawsonia intracellularis (LI)-related diarrhoea. A randomised clinical trial was carried out in four Danish pig herds, including a total of 520 pigs from 36 nursery batches. A high prevalence of LI was demonstrated in all herds prior to the initiation of the study. Treatment efficacy was assessed by faecal shedding of LI, the occurrence of diarrhoea and average daily weight gain (ADG) after treatment. All strategies were implemented at batch level at presence of LI-related diarrhoea and included daily treatment with 10mg oxytetracycline (OTC) per kilogram of bodyweight for 5 days, though the OTC was administered differently: either by oral treatment of all pigs in a batch, by oral treatment of pigs in diarrhoeic pens only, or by intramuscular treatment of individual diarrhoeic pigs only. The treatment strategies were randomly allocated to batches and were initiated at the presence of diarrhoea. From the included batches, 100% of the trial pigs were medicated in the batch treatment strategy, 87% in the pen treatment strategy and 55% in the individual treatment strategy. All strategies reduced the occurrence of diarrhoea and faecal shedding of LI after treatment. However, batch treatment was found to be most efficient in reducing both high-level LI shedding and diarrhoea when compared to the treatment of diarrhoeic pens or individual diarrhoeic pigs. There was no significant difference identified in ADG between the treatment strategies. In conclusion, batch treatment of all pigs in a section resulted in the highest efficacy for reducing diarrhoea and faecal shedding of LI.

Topics: Administration, Oral; Animals; Anti-Infective Agents; Bacterial Shedding; Desulfovibrionaceae Infections; Diarrhea; Feces; Female; Injections, Intramuscular; Lawsonia Bacteria; Male; Oxytetracycline; Swine; Swine Diseases; Treatment Outcome; Weight Gain

In-feed antibiotics have been commonly used to promote the growth performance of piglets. The antibiotics can increase protein utilization, but the underlying mechanism is largely unknown. The present study investigated the effects of in-feed antibiotics on intestinal AA transporters and receptors to test the hypothesis that the alteration of circulating AA profiles may be concomitant with the change of intestinal AA transporters and receptors. Sixteen litters of piglets at day 7 started to receive creep feed with (Antibiotic) or without (Control) antibiotic. Piglets were weaned at day 23 after birth, and fed the same diets until day 42. In-feed antibiotics did not affect the BW of 23-day-old (P = 0.248), or 42-day-old piglets (P = 0.089), but increased the weight gain to feed ratio from day 23 to 42 (P = 0.020). At day 42 after birth, antibiotic treatment increased the concentrations of most AAs in serum (P < 0.05), and decreased the concentrations of most AAs in jejunal and ileal digesta. Antibiotics upregulated (P < 0.05) the mRNA expression levels for jejunal AAs transporters (CAT1, EAAC1, ASCT2, y

Topics: Amino Acid Transport System ASC; Amino Acids; Animal Feed; Animals; Animals, Newborn; Anti-Bacterial Agents; Biological Transport; Excitatory Amino Acid Transporter 3; Gene Expression Regulation; Kitasamycin; Large Neutral Amino Acid-Transporter 1; Oxytetracycline; Peptide Transporter 1; Quinoxalines; Receptors, Calcium-Sensing; Receptors, G-Protein-Coupled; RNA, Messenger; Sodium-Potassium-Exchanging ATPase; Swine; TRPV Cation Channels; Weaning; Weight Gain

The non-antibiotic anti-inflammatory theory of antimicrobial growth promoters (AGP) predicts that alternatives can be selected by simple in vitro tests. In vitro, the known AGP oxytetracycline (OTC) and a Macleaya cordata extract (MCE) had an anti-inflammatory effect with a half-maximal inhibitory concentration of 88 and 132 mg/l, respectively. In vivo, chickens received three different concentrations of MCE in drinking-water, OTC in feed and a control. Body weight (BW), feed intake (FI) and gain:feed (G:F) ratio were determined on days 14, 21 and 35. On day 35, body composition was determined. Plasma α1-acid glycoprotein (α1-AG) concentration was measured on days 21 and 35, and the expression of several jejunal inflammatory genes was determined on day 35. OTC-fed chickens showed a significantly higher BW, FI and G:F ratio compared with the control group at all time points. MCE had a significant linear effect on BW on days 21 and 35, and the G:F ratio was improved only over the whole period, whereas FI was not different. Only MCE but not OTC decreased the percentage of abdominal fat. Plasma α1-AG concentration increased from day 21 to 35, with the values being lower in the treatment groups. Both OTC and MCE significantly reduced the jejunal mucosal expression of inducible NO synthase. For most parameters measured, there was a clear linear dose-response to treatment with MCE. In conclusion, the results are consistent with the anti-inflammatory theory of growth promotion in production animals.

Topics: Animals; Anti-Inflammatory Agents; Body Composition; Body Weight; Chickens; Gene Expression; Inflammation; Interleukin-10; Interleukin-1beta; Intestinal Mucosa; Jejunum; Male; Nitric Oxide Synthase Type II; Orosomucoid; Oxytetracycline; Papaveraceae; Phytotherapy; Plant Extracts; Weight Gain

To characterize the impact of Mannheimia haemolytica infection on feed intake and weight gain in feedlot heifers and to evaluate the clinical efficacy of isoflupredone acetate administered in combination with oxytetracycline.. 96 weanling heifers in a research feedlot facility.. Bronchopneumonia was induced by intrabronchial infusion of M haemolytica. Control heifers underwent a sham procedure. Infected heifers were treated with oxytetracycline alone or in combination with isoflupredone acetate (OXY-ISO) or with nothing. Clinical variables were recorded daily for 7 days following disease induction, and feedlot performance indices were measured over a 12-week period.. Infection caused a reduction in dry-matter intake and average daily gain (ADG) in heifers that received no treatment. Oxytetracycline treatment alone did not prevent reductions in feed intake and ADG during the first week after infection was induced, whereas OXY-ISO treatment did prevent these reductions. Treatment with OXY-ISO also resulted in faster clinical improvement. No significant differences were evident between the oxytetracycline and OXY-ISO groups with respect to dry-matter intake or ADG throughout the study period.. Isoflupredone acetate appeared to be a useful clinical adjunct to treatment with oxytetracycline in cattle with acute M haemolytica bronchopneumonia.

Topics: Animals; Antibodies, Bacterial; Bronchopneumonia; Cattle; Dairying; Drug Therapy, Combination; Feeding Behavior; Female; Fluprednisolone; Glucocorticoids; Hydrocortisone; Mannheimia haemolytica; Ontario; Oxytetracycline; Pasteurellosis, Pneumonic; Random Allocation; Weight Gain

The purpose of this study was to determine the efficacy and cost-effectiveness of tulathromycin (DRAX) versus tilmicosin (MIC) or oxytetracycline (TET) as a metaphylactic antimicrobial in feedlot calves. Calves that received DRAX had significantly (P<.05) lower initial undifferentiated fever (UF) treatment and relapse rates; lower overall chronicity, overall mortality, and cause-specific mortality rates; higher average daily gains; and improved quality grades. However, calves that received DRAX also had poorer (P<.05) yield grades compared with calves that received MIC or TET and worse feed conversion compared with calves that received MIC. Net advantages in the DRAX group were 3.79CanDollars/animal and 16.96CanDollars/animal compared with the MIC and TET groups, respectively. Based on these results, DRAX is a more efficacious and cost-effective metaphylactic antimicrobial than MIC or TET in feedlot calves at ultra-high risk of developing UF. In addition, this study presents a comparison between two methods ("deads out" and "deads in") of calculating feedlot performance variables.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Canada; Cattle; Cattle Diseases; Cost-Benefit Analysis; Disaccharides; Eating; Female; Fever; Heterocyclic Compounds; Macrolides; Meat; Oxytetracycline; Random Allocation; Recurrence; Treatment Outcome; Tylosin; Weight Gain

Eighty steers with a mean body weight of 319 kg were used in a study to evaluate the effect of a growth-promoting implant (trenbolone acetate plus estradiol benzoate), monensin, and oxytetracycline on the steer performance and shedding of some foodborne pathogens. The steers were allotted to one of eight treatment combinations according to a randomized complete block design with 16 pens of five animals. Rectal fecal samples were collected before treatment commenced and over a period of more than 24 weeks to study the influence of treatments on the intestinal microbiology of the animals. Results supported the beneficial effect of the hormonal implant on the performance of feedlot steers (average daily gain, feed efficiency, and fat thickness), on carcass characteristics (hot carcass weight, lean yield), and economic value of the carcasses (P < 0.01). The levels of Escherichia coli in feces were not affected by treatments but remained high throughout the study period. Antibiotic-resistant isolates of E. coli were more frequently found as the study progressed but were not associated with any specific treatment. Also independently of treatment, we observed a reduction over time in the shedding of Campylobacter and Yersinia during the feeding period, whereas the shedding of Enterococcus was increased. The results of this study confirmed the beneficial economic effect of growth-promoting agents in beef production and showed that the agents tested did not specifically affect the overall microbial evolution of the animal gut. However, the study also showed, independently of the growth promoter used, the shedding of Campylobacter, Yersinia, and antibiotic-resistant E. coli in the feedlot environment. These bacteria also may be found in the colonic tissue of steers at slaughter and might be a source of carcasses contamination.

Topics: Anabolic Agents; Animals; Anti-Bacterial Agents; Campylobacter; Cattle; Colon; Colony Count, Microbial; Cost-Benefit Analysis; Eating; Escherichia coli; Escherichia coli O157; Estradiol; Feces; Male; Microbial Sensitivity Tests; Monensin; Oxytetracycline; Random Allocation; Trenbolone Acetate; Weight Gain; Yersinia

Forty-five Holstein calves were fed milk replacers containing either antibiotics [MRA (oxytetracycline at 138 mg/kg and neomycin at 276 mg/kg), n = 22)] or Enteroguard [MRE, a blend of fructooligosaccharides, allicin, and gut-active microbes at (129 mg/kg, n = 23)] from birth to 5 wk of age to compare effects on average daily gain and on incidence of scours. Performance was evaluated by measuring weight gain, feed efficiency, and fecal scores. The overall body weight gains and severity of scours were not different between treatments, nor were there differences in starter intake or mean body weight gain. During wk 2, the average gain of calves fed MRA was less than that of calves fed MRE (0.07 vs. 0.09 kg/d, P = 0.09), and greater during wk 5 (0.62 vs. 0.51 kg/d, P < 0.01); however, total gain for calves fed MRE was not different from calves fed MRA. Likewise, average feed efficiencies (gain/dry matter intake) were not different. Severity of scours, as measured by fecal scores, and concentrations of serum proteins, an indirect measure of immunoglobulins, were similar for calves fed MRA and MRE. The results suggest that antibiotics in milk replacers can be replaced with compounds such as fructooligosaccharides, probiotics, and allicin to obtain similar calf performance.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Animals, Newborn; Anti-Bacterial Agents; Anti-Infective Agents; Cattle; Diarrhea; Disulfides; Feces; Female; Food, Formulated; Incidence; Male; Neomycin; Oligosaccharides; Oxytetracycline; Probiotics; Random Allocation; Sulfinic Acids; Weight Gain

Spring-calving multiparous Angus x Hereford cows were used to determine the efficacy of intramuscular treatment with oxytetracycline to reduce the incidence of mastitis-causing bacteria, decrease milk somatic cell counts (SCC), and increase calf growth. During 2 yr, milk samples were collected from each quarter from a total of 319 cows at 8 to 14 d after calving and at weaning, to determine the presence of bacteria and SCC. A California mastitis test (CMT) was performed on milk from each quarter of each cow at the initial sample collection. Cows with a CMT score of 1, 2, or 3 in at least one quarter, were randomly assigned to receive either an intramuscular injection of oxytetracycline (n = 63) or the control vehicle (n = 60), and cows with a CMT score of 0 or trace in all four quarters were not treated (n = 196). Calf weights were determined at birth, early lactation, and weaning. The number of somatic cells in milk and the percentage of quarters that were infected increased as CMT score increased (P < 0.01). The presence of mastitis-causing bacteria at calving increased (P < 0.05) the incidence of infection at weaning. The presence of mastitis-causing bacteria at weaning was associated with increased SCC for quarters and average SCC for cows (P < 0.01). Average SCC per cow at weaning increased (P < 0.05) as the number of infected quarters per cow increased. Treatment did not alter (P > 0.10) the percentage of cows or quarters infected with mastitis-causing bacteria or SCC of cows or quarters at weaning. Average SCC per cow was negatively correlated (P < 0.05) with calf weights at early lactation, but not with weaning weights of calves. Treatment did not influence (P > 0.10) calf weights at early lactation or at weaning. Cows with one or more dry quarters after calving had calves that weighed less at early lactation and weaning than cows with four functional quarters (P < 0.01). Intramuscular oxytetracycline treatment of beef cows that had CMT scores of 1 or greater after calving did not reduce intramammary infection rates or increase calf weights at weaning.

Topics: Animals; Animals, Suckling; Anti-Bacterial Agents; Cattle; Cell Count; Female; Injections, Intramuscular; Mastitis, Bovine; Milk; Oxytetracycline; Treatment Outcome; Weaning; Weight Gain

Holstein bull calves (n = 96) were purchased at approximately 7 d of age and were assigned to receive 400, 450, 500, and 550 g/d of milk replacer solids during wk 1 to 4, respectively. Treatments were nonmedicated milk replacer plus dried whey, medicated milk replacer (138 mg/kg of oxytetracycline and 276 mg/kg of neomycin) plus dried whey, or nonmedicated milk replacer plus whey processed with beta-galactosidase to contain 15% galactosyl-lactose. Processed whey was added to provide 1% of dry matter as galactosyl-lactose; an equivalent amount of dried whey was added to the other treatments to provide 6.3% of dry matter daily. Intake of milk replacer and fecal scores were measured daily. No calf starter or hay was fed. Body weights were measured weekly from arrival to 26 d. Serum immunoglobulin G, measured 1 d after arrival, averaged 18.3 g/L. Intake of milk replacer plus additive during the 26-d study was 445 g/d and did not vary with treatment. Body weight and body weight gain were increased by 52 and 72 g/d in response to antibiotics and galactosyl-lactose, respectively. Severity of scours and number of days scouring tended to be reduced when calves were fed milk replacer containing galactosyl-lactose or antibiotics.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Anti-Bacterial Agents; Cattle; Feces; Female; Food, Formulated; Galactose; Lactose; Male; Milk; Neomycin; Oxytetracycline; Trisaccharides; Weight Gain

Clinical and hematological changes of six Anaplasma marginale (isolated Zulia) inoculated calves (experimental group) and four healthy calves (control group) were studied during twenty and eighty days before and after infection, respectively. The behavior of the four calves used as control group was stable and no significant changes in the parameters analyzed was observed. The experimental group developed the three typical phases of illness. During the prepatent phase, which lasted a mean of 21.2 +/- 2.56 days, the animals were asymptomatic and no significant changes in the hematological values occurred, but a remarkable transitory decrease in number of lymphocytes from 6.5 x 10(6) to 3.3 x 10(6) cells/ml. The infection during the acute phase produced a highly severe effect in two animals, a severe effect in three animals and a mild effect in one. The effects observed were the following: 1) a fast decrease in haematocrite, ranging from 6 to 10%; 2) values of parasitaemia varied from 15 to 48%; 3) a greater body temperature than the control animals (40.5 vs. 38.5 degrees C); 4) a elevated heart frequency, from 60 to 110 beats/min; 5) an increase in the concentration of neotrophiles from 10 x 10(6) to 13 x 10(6) cells/ml; 6) The number of monocytes also augmented from 3 x 10(6) to 6 x 10(6) cells/ml; and 7) an important decrease of weight gain. The natural course of infection was interrupted with oxytetracycline when the haematocrite of the animal lowered to values less or equal to 10%. Then, the animals showed a rapid recovery with an undetectable parasitaemia and concomitant return to basal line of the rest of the parameters.

Topics: Anaplasmosis; Animals; Blood Cell Count; Body Temperature; Cattle; Heart Rate; Oxytetracycline; Parasitemia; Respiration; Weight Gain

The effects of supplemental chromium (Cr) from high-Cr yeast were investigated with steer calves fed corn silage diets. One hundred eight Charolais-crossed calves, weighing 245 kg after marketing and transport, were allotted to one of four treatments during the initial 28-d stress period: control, .4 ppm of Cr in the diet, long-acting injectable oxytetracycline (LAOTC), and Cr + LAOTC. Those fed Cr received 4 mg of Cr/d for the first 3 d sprinkled onto a small amount of hay over the silage. Chromium without LAOTC increased (P less than .05) ADG by 30% (.61 vs .79 kg/d) and ADG/DMI by 27% (.123 vs .156). Oxytetracycline alone increased (P less than .05) ADG by 30% and DMI by 15%. Chromium had no effect on morbidity. However, LAOTC tended (P less than .14) to reduce morbidity (26.0 vs 14.0%) after its administration. After d 28, steers were processed. Two weeks later, they were rerandomized within Cr groups to urea-corn vs soybean meal supplementation of corn silage during a 70-d growing period. Level of Cr was reduced to .2 ppm. Jugular blood was collected from eight steers on each treatment on two occasions. Chromium had no effect on ADG or ADG/DMI. However, Cr decreased (P less than .05) serum cortisol (75.0 vs 55.6 nmol/L). Furthermore, Cr increased (P less than .05) serum immunoglobulin M and total immunoglobulins in calves fed diets with soybean meal but had no effect in calves with urea-corn supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Blood Glucose; Blood Proteins; Cattle; Cattle Diseases; Chromium; Eating; Hydrocortisone; Immunoglobulins; Male; Morbidity; Oxytetracycline; Silage; Stress, Physiological; Urea; Weight Gain; Zea mays

An experiment was conducted to determine the effects of 1) long-acting oxytetracycline injection at market arrival, 2) feed or water access at the auction market and 3) receiving diet management on commingled feeder pig performance. A total of 288 commingled feeder pigs transported over 1,000 km after market management treatments were used in two trials. Pigs given access to feed and water (FW) at the market weighed more (P less than .001) following marketing and transport than pigs given water only (W). Pigs given neither feed nor water (N) were intermediate in arrival weight (19.7, 18.7 and 18.9 kg). There was no effect (P greater than .1) of feed and water offering at the market on final weight (96.6, 95.9 and 96.6 kg), overall average daily gain (.70, .69 and .70 kg/d), overall gain/feed (.31, .31, .32) or percentage death loss (1.0, 2.1 and 4.2%). Injection of long-acting oxytetracycline upon arrival at auction market had no effect (P greater than .1) on pig weight following marketing and transport (19.0 vs 19.2 kg), final weight (96.1 vs 97.0 kg), percentage death loss (3.4 vs 1.4%) or percentage of pigs treated (3.4 vs 4.9%). Compared to providing ad libitum access to feed, restricting feed intake by floor feeding for the first 7 d post-arrival reduced (P less than .01) rate of gain for the first 9 d (-.04 vs. .08 kg/d), but overall there was no effect (P greater than .1) on daily gain (.70 vs .69 kg/d) or gain/feed (.31 vs .31).

Topics: Animal Feed; Animals; Diet; Food Deprivation; Oxytetracycline; Random Allocation; Swine; Water Deprivation; Weight Gain; Weight Loss

Prophylactic efficacy of 100 mg of long-acting oxytetracycline (OTC) given IM to neonatal pigs within 12 hours of birth was evaluated in a swine herd. The herd had a history of increased neonatal mortality, diarrhea, foot abscess, and arthritis in nursing pigs. Two trials were conducted in which liters and individual pigs were the treatment groups of interest. In both trials, OTC treatment failed to reduce mortality, diarrhea, or arthritis or the need for subsequent antimicrobial therapy (P greater than 0.05). Preweaning weight gains were not increased (P greater than 0.05) in treated pigs. However, in the individual pig trial, foot abscess rates were significantly (P = 0.01) lower in treated pigs (3.7%) than in nontreated pigs (8%). Aerobic bacteria isolated from pigs with diarrhea, arthritis, or foot abscess had minimum inhibitory concentrations for OTC greater than or equal to 64 micrograms/ml or were classed as resistant on the basis of disk-diffusion tests.

Topics: Abscess; Animals; Animals, Newborn; Arthritis, Infectious; Bacterial Infections; Diarrhea; Female; Foot Diseases; Male; Oxytetracycline; Prognosis; Random Allocation; Swine; Swine Diseases; Weight Gain

Topics: Animals; Chickens; Meat; Oleandomycin; Oxytetracycline; Poultry; Weight Gain

Topics: Body Weight; Growth; Oxytetracycline; Weight Gain