chlortetracycline and Body-Weight

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Bentonite; Body Weight; Charcoal; Chlortetracycline; Diethylstilbestrol; Feces; Female; Food Additives; Male; Melengestrol Acetate; Methionine; Molasses; Poaceae; Pregnancy; Rumen; Sheep; Silage; Sodium Hydroxide; Sulfamethazine; Wood; Zea mays

Topics: Animal Diseases; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Anti-Bacterial Agents; Bacitracin; Body Weight; Cattle; Chlortetracycline; Food Additives; Meat; Oxytetracycline; Penicillin G Procaine; Poultry; Sheep; Swine

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Anti-Bacterial Agents; Body Composition; Body Weight; Chlortetracycline; Growth; Oxytetracycline; Swine; Time Factors

Topics: Animal Diseases; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Anti-Bacterial Agents; Bacitracin; Body Weight; Cattle; Chlortetracycline

The pleuromutilin antibiotic tiamulin (TIA) is known to produce a negative interaction in broilers when administered in combination with several ionophore anticoccidials such as salinomycin (SAL). Chlortetracycline (CTC), when administered simultaneously with TIA, has demonstrated a synergistic antimicrobial effect. A 35-d feeding study was conducted in cages to evaluate the interaction effect of a combination of TIA plus CTC at increasing inclusion levels when administered concurrently with SAL. A total of 200 one-day-old broiler chicks were distributed into 4 groups, and each group consisted of 5 cages containing 10 birds in each. Replicate cages were distributed randomly. Feed for all groups contained 60 ppm SAL, but additionally, 0, 20, 30, and 50 ppm TIA and 0, 60, 90, and 150 ppm CTC were included, respectively. Several enzymes (creatine phosphokinase, lactate dehydrogenase, and aspartate aminotransferase) were determined from blood samples taken at the end of the trial. Blood samples were also collected during d 0, 19, and 35 and were analyzed for antibody titers against Mycoplasma gallisepticum and Mycoplasma synoviae. Necropsy of a few birds (20, 8, 20, 12, and 12 on d 7, 14, 21, 28, and 35, respectively) was conducted at weekly intervals. Results indicated that there was a significant depression of weight gain (P < 0.05) in group 4 (TIA 50 + CTC 150) only. The final weights were 1,809 +/- 130, 1,859 +/- 52, 1,703 +/- 47, and 1,617 +/- 98 g for groups 1 (TIA 0 + CTC 0), 2 (TIA 20 + CTC 60), 3 (TIA 30 + CTC 90), and 4 (TIA 50 + CTC 150), respectively. However, feed intake and feed conversion efficiency (g of weight gain/kg of feed intake) were not significantly affected in any of the groups. There was no dose-related adverse effect on mortality or clinical signs exhibited during the trial, and this was supported by necropsy. Maternally derived antibodies against M. gallisepticum were present at the beginning of the trial but disappeared within 19 d. Otherwise, there was no apparent infection by M. gallisepticum or M. synoviae throughout the trial. The results demonstrate that 50 ppm TIA plus 150 ppm CTC along with 60 ppm SAL caused only a depression of growth, but no adverse signs of interaction were detected. Taking into consideration all the aspects of the cost of production, the 20 ppm TIA plus 60 ppm CTC was the most cost-effective level to administer continuously with 60 ppm SAL via the feed, but it would be important to do an additional stud

Topics: Animals; Anti-Bacterial Agents; Aspartate Aminotransferases; Body Weight; Chickens; Chlortetracycline; Coccidiostats; Creatine Kinase; Diterpenes; Drug Synergism; Female; L-Lactate Dehydrogenase; Male; Poultry Diseases; Pyrans

The effectiveness of a feed-additive antimicrobial combination for improving feedlot performance and health was tested using 4325 high-risk feeder calves randomly allocated to a control group or an experimental group. The experimental group received the conventional ration plus a feed additive containing 700 mg per head/day of chlortetracycline and sulfamethazine from arrival at the feedlot to day 56 of the feeding period. The inclusion of the feed additive to the ration significantly improved average daily gain for days 0-28 (P = 0.0163) and 0-56 (P = 0.0001), and the feed conversion for days 0-28 (P = 0.0061) and 0-56 (P = 0.0004). Additionally, the use of the feed additive significantly reduced the rate of bovine respiratory disease morbidity for days 0-28 (P = 0.0014) and 0-56 (P = 0.0001), the rate of relapses and mortality for days 0-56 (P = 0.0151 and P = 0.0209, respectively), and the rate of animals diagnosed with chronic respiratory disease for days 0-28 and 0-56 (P = 0.0009 and P = 0.0002, respectively). Performance and health improvements produced by the use of the feed additive were cost-effective.

Topics: Animal Feed; Animals; Body Weight; Cattle; Cattle Diseases; Chlortetracycline; Energy Metabolism; Female; Male; Respiratory Tract Infections; Sulfamethazine; Time Factors

Our objective was to determine the effects of preshipping (PRE) vs. arrival (ARR) medication with tilmicosin phosphate (MIC; Exp. 1 and 2) and feeding chlortetracycline (CTC; 22 mg/kg of BW from d 5 to 9; Exp. 2) on health and performance of beef calves received in the feedlot. Ninety-six steers (Exp. 1; pay weight 236 kg) and 240 (Exp. 2; average pay weight 188 kg) steer and bull calves were used. For Exp. 1, treatments included no MIC (CON), PRE, and ARR. For Exp. 2, treatments were arranged in a 3x2 factorial. Treatments included CON, PRE, and ARR, either with CTC or without CTC. For Exp. 2, serum concentrations of immunoglobulin (Ig)G and alpha-1-acid glycoprotein (AGP) were determined on samples collected on d 0, 5, 10, and 28 and d 0, 5, and 10, respectively. No MIC x CTC interactions were observed. No differences were noted among MIC or CTC treatments in any of the experiments for ADG, daily DMI, or gain:feed ratio for the overall receiving periods. For Exp. 1, percentage of steers treated for bovine respiratory disease (BRD) was decreased (P<.05) for MIC-treated animals vs CON (71.9, 45.2, and 46.9 for CON, PRE, and ARR, respectively), and the week that calves were treated for BRD differed (P<.10) among treatments. For Exp. 2, the number of calves treated for BRD was decreased (P<.01) for MIC-treated steers vs CON and decreased (P<.05) for ARR vs. PRE (40.0, 18.7, and 7.5% for CON, PRE, and ARR, respectively). Averaged across days, serum IgG was decreased (P<.05) for MIC-treated steers vs. CON, with no differences noted among treatments for AGP. Results suggest that preshipping medication programs are no more effective than arrival medication programs using tilmicosin phosphate.

Topics: Animals; Anti-Bacterial Agents; Body Weight; Cattle; Chlortetracycline; Immunoglobulin G; Macrolides; Male; Orosomucoid; Transportation; Tylosin

Thirty-two beef steers (285 +/- 3 kg BW) were used to determine the effects of chlortetracycline and dietary protein level on visceral tissue mass, chemical composition, intestinal morphology, and proliferation rate indices. Steers were allotted randomly by weight to a factorial arrangement of dietary treatments consisting of either 10 or 13% CP diets top-dressed with a corn meal carrier (500 g/d) containing either 0 or 350 mg of chlortetracycline. After 84 d, steers were slaughtered and visceral organs removed and separated. Rinsed wet tissue mass was recorded; total RNA, total DNA, tissue DM, and tissue N content were determined; and tissue sections were prepared for immunohistochemical analysis. Thin tissue sections were evaluated to determine crypt depth and villus height as well as proliferation rate by immunohistochemical detection of the nuclear antigen Ki67. Rumen and abomasum weights and small intestinal length were greater (P < 0.04) in steers fed the 13% CP diet than in those fed the 10% CP diet on both an absolute weight basis and a percentage of empty BW. Chemical composition of the small intestinal and ruminal segments were largely unaffected by increased dietary protein. Increasing the dietary CP also increased the villus height in duodenal (P = 0.02) and the crypt depth of jejunal (P = 0.03) sections. Dietary administration of chlortetracycline decreased (P < 0.01) small intestinal weight both on absolute and empty BW bases. Nitrogen and RNA concentrations of the small intestinal segments were unaffected (P > 0.1) by dietary administration of subtherapeutic levels of chlortetracycline; however, because of increases (P < 0.05), or tendencies for an increase (P < 0.1), in the tissue content of DNA, the ratio of N to DNA was decreased (P < 0.05) or tended to be decreased (P < 0.1) in the small intestinal segments of the chlortetracycline-treated animals. The observed decrease in small intestinal epithelial mass does not appear to be due to alterations in cell proliferation rate but rather cell size. Consistent with this finding, cell proliferation, as determined by Ki67 antigen staining, was not affected by dietary treatment. Chlortetracycline administration decreased small intestinal mass that may be a result of decreased cell size.

Topics: Administration, Oral; Animals; Body Weight; Cattle; Cell Division; Chlortetracycline; Dietary Proteins; Enterocytes; Male; Random Allocation; Viscera

The effects of continuous oral administration of antibiotics in mice were investigated. Sulfamerazine, ampicillin, and chlortetracycline were tested at a rate of 500 mg/L of drinking water. Mice were infected by intranasal inoculation with 10(6) bacilli of the SMR strain of cilia-associated respiratory (CAR) bacillus. The mice were treated with the antibiotics starting 1 week before, 1 week after, or 4 weeks after the inoculation, for 5, 3, or 4 weeks respectively, then were examined. The infected mice lost body weight, and this loss was prevented or regained by all of the antibiotic treatments. Serologically no antibodies were detectable in the mice administered sulfamerazine starting 1 week before the inoculation. Mice administered sulfamerazine starting 1 week after the inoculation and ampicillin or chlortetracycline starting 1 week before or after the inoculation yielded a low titer of antibodies compared with nontreated infected mice. Mice administered antibiotics starting 4 weeks after the inoculation yielded the same titer of antibodies as nontreated infected mice. No pathologic respiratory tract lesions were observed in mice administered sulfamerazine starting 1 week before the inoculation. Mice administered sulfamerazine starting 1 week after the inoculation or ampicillin starting 1 week before or after the inoculation had slight peribronchitis without CAR bacillus colonization. Mice administered chlortetracycline, starting either 1 week before or after inoculation, developed peribronchitis, with colonization of the bacillus on the airway mucosa. In mice medicated starting 4 weeks after the inoculation, respiratory tract lesions developed, but their severity was reduced. The airway mucosa in mice treated with chlortetracycline was associated with the CAR bacillus but not in mice treated with sulfamerazine and ampicillin. These findings suggest that prevention and eradication of CAR bacillus infection is possible by treatment with sulfamerazine.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Antibodies, Bacterial; Body Weight; Bronchi; Chlortetracycline; Drug Administration Schedule; Female; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Mice; Mice, Inbred BALB C; Respiratory System; Respiratory Tract Infections; Rodent Diseases; Specific Pathogen-Free Organisms; Sulfamethazine; Time Factors

To determine if feed contaminants and feed additives interact, day-old chicks from lines bred for high and low antibody response to sheep erythrocytes were fed aflatoxin at a level of 3,000 ppb, chlortetracycline at a level of 550 ppm, or a combination of aflatoxin and chlortetracycline for a period of 6 wk. Weight gain in both lines of chicks was adversely affected by the aflatoxin treatment. There was a synergistic adverse effect in chicks of the low antibody response line when given chlortetracycline as well as aflatoxin, an effect not noted in chicks of the high antibody response line. Chlortetracycline alone had no effect on weight gain of low antibody response birds but increased the weight gain of chicks from the high antibody response line. Bursa to body weight ratios were adversely affected by aflatoxin in both lines of chicks, but chlortetracycline further adversely affected this parameter only in the low antibody response line. These results indicate that adverse effects of aflatoxin may be enhanced by addition of antibiotics to feed.

Topics: Aflatoxins; Animal Feed; Animals; Body Weight; Chickens; Chlortetracycline; Drug Interactions; Food Additives

In two experiments the effects of unhulled sunflower seeds (USFS) were evaluated at levels of 19 and 38% in corn-based diets for pullets between 10 and 19 wk of age. As an additional treatment a .09%-lysine monohydrochloride supplement was added to the 38% USFS-containing diet in Experiment 2. Isonitrogenous grower diets made up of corn and soybean meal or largely oats served as control diets. During the productive phase, layers were fed a high oats diet as mash (both experiments) or in pelleted form (Experiment 2). One half of the hens in each study were fed layer diets containing Aureomycin at 100 g per ton for 1 wk during each 28-day period to monitor the effect on egg production. Treatments during the laying phase were superimposed on the previous growing phase treatments. Pullets fed the 38% USFS diet in Experiment 1 were significantly lighter (P less than .01) at 19 wk of age and reached 50% egg production 2 days later than those on the control corn-soy diet. However, subsequent overall laying performance for 14 28-day periods was not significantly affected by the growing treatments. Neither growth nor laying performance was influenced by the treatments imposed during the rearing period of the second experiment. The two supplies of USFS varied considerably in crude fiber (14.6 vs 25.8%) and ether extract components (42.4 vs. 29.0%, respectively). The discrepancy in growth response to USFS of the two experiments was possibly related to the difference in the ether extract portions of the oil seeds. Egg production rate was significantly increased by Aureomycin only when the diet was pelleted.

Topics: Animals; Body Weight; Chickens; Chlortetracycline; Dietary Proteins; Female; Helianthus; Oviposition; Plant Proteins; Seeds

Two 56-d shipping fever trials of similar design were conducted the same season (fall) at Kansas State University (KSU) and at Purdue University (PU) to compare various levels of chlortetracycline (0 or 350 mg X head-1 X d-1 continuously or 1, 2 or 4 g X head-1 X d-1 for the first 14 d). Weanling crossbred steer calves were utilized (210 head of Angus X Simmental, averaging 197 kg, at KSU; 268 head of Angus X Hereford, averaging 192 kg, at PU). For the first 28 d in the KSU trial (October 13 to December 8), cattle that received 4 g X head-1 X d-1 the first 14 d gained more rapidly (P less than .05) than cattle fed 350 mg X head-1 X d-1 continuously or than the controls that received no chlortetracycline (CTC; 1.05 vs .92 or .93 kg/d, respectively). Cattle that received 4 g CTC X head-1 X d-1 for the first 14 d required less (P less than .05) dry matter per kg gain than steers that received 350 mg X head-1 X d-1 continuously over the 56-d period. In the PU trial (October 6 through December 1), all CTC treatments resulted in increased feed efficiency (P less than .05) over the controls through 28 d, and the 4 g X head-1 d-1 for 14 d and 350 mg X head-1 X d-1 continuously, improved feed efficiency over the other groups for the 56-d period.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Chlortetracycline; Male; Pasteurella Infections; Pasteurellosis, Pneumonic

Three levels of sodium diacetate (.625, 1.25, and 3.75 g/kg diet) were incorporated into the diets of day-old broiler chicks. A control ration and a 20 mg/kg aureomycin ration were fed to additional groups of chicks. Each treatment contained 40 chickens at 3 weeks; the number was reduced to 20 chickens at 5 and 8 weeks. At 3 and 8 weeks of age, the large and small intestines of 5 chickens from each treatment were examined for selected microorganisms. Chick growth and feed efficiency were also recorded. The entire experiment was run twice, but in Trial 2 the lowest level of sodium diacetate treatment was replaced by a combination of sodium diacetate (.625 g/kg diet) and aureomycin (20 mg/kg diet). No improvement in the rate of growth was found in the sodium diacetate-treated groups, although additional weight gain was detected in aureomycin-fed groups at 2 weeks of age. Improved feed efficiency in the treated groups (sodium diacetate and aureomycin) was observed in both trials at 2 weeks and at 3 weeks of age in Trial 1. No feed efficiency effects were observed after that time. The sodium diacetate-fed groups showed an increased lactobacilli population in the small intestine along with a concurrent decrease in streptococci. The effect of sodium diacetate in reducing total coliforms in the large intestine was more obvious at 3 weeks than at 8 weeks. Aureomycin appeared to suppress the population of lactobacilli and total coliforms in this study. A combination of sodium diacetate and aureomycin failed to exhibit a synergistic effect either on the growth rate or on the intestinal microflora.

Topics: Acetates; Acetic Acid; Animal Feed; Animals; Bacteria; Body Weight; Chickens; Chlortetracycline; Energy Metabolism; Enterobacteriaceae; Food Additives; Intestines; Lactobacillus; Species Specificity; Streptococcus

Three experiments were conducted to determine the effect of receiving diets containing alfalfa meal and certain feed additives on performance of comingled feeder pigs transported 900 to 1,100 km. In Exp. 1, the inclusion of 9.4% dehydrated alfalfa meal in receiving diets for 2 wk resulted in no difference (P greater than .1) in gain or feed conversion from purchase to market compared with pigs fed a basal corn-soybean meal (CS) diet or a diet containing 20% ground whole oats (O). In Exp. 2, pigs fed receiving diets containing 10% dehydrated alfalfa meal had no improvement (P greater than .1) in gain (.60 vs .61 kg/d) or conversion (3.25 vs 3.17) compared with CS-fed pigs. In Exp. 3, pigs fed a receiving diet for 2 wk containing 10% mid-bloom alfalfa ate more (P less than .002) feed daily for 2 wk (.82 vs .76 kg) and overall (P less than .04; 1.92 vs 1.85 kg) and had an improved (P less than .03) daily gain from purchase to market (.61 vs .59 kg) compared with CS-fed pigs. In Exp. 2, pigs fed diets containing 44 mg/kg tylosin (T) gained similar to pigs fed no additive (O) and slower (P less than .01) than pigs fed 110 mg/kg chlortetracycline (CTC; .59, .60 and .63 kg/d), with no significant differences in feed to gain conversion (3.12, 3.23 and 3.18).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animal Feed; Animals; Bacitracin; Body Weight; Chlortetracycline; Diarrhea; Female; Food Additives; Leucomycins; Male; Medicago sativa; Salicylates; Swine; Swine Diseases; Transportation; Tylosin

Day-old broiler chicks were fed 0, 1.25, 2.5, and 5.0 micrograms aflatoxin/g of feed for 3 weeks. Chlortetracycline (CTC) was administered in the drinking water at a concentration of 50 mg/liter for 27 hr starting on Day 21. Three hours after initiation of the CTC treatment, birds receiving 2.5 and 5.0 micrograms/g dietary aflatoxin had significantly lower CTC in blood compared with the controls. At 12 and 27 hr after the initiation of CTC treatment, birds receiving any level of aflatoxin had significantly decreased blood levels of CTC compared with the controls. Intravenous injection of CTC of control birds and birds receiving 2.5 micrograms/g aflatoxin revealed a significant decrease in the elimination half-life of CTC and a significant increase in the total systemic clearance of CTC in the birds receiving dietary aflatoxin. Birds receiving 2.5 micrograms/g dietary aflatoxin also had a significant increase in the volume of gall bladder bile; however, this did not result in a greater amount of CTC being eliminated via bile. Studies on protein binding of CTC in the plasma of control birds and the plasma of birds receiving 2.5 micrograms/g dietary aflatoxin demonstrated that 60% more CTC is "free", or unbound, in the plasma of birds receiving no aflatoxin. These results suggest that aflatoxicosis lowers the plasma concentrations of CTC as a result of a decreased binding of CTC to plasma protein. This allows more unbound CTC to be available for elimination from the plasma by a means other than the liver, most likely via the kidney.

Topics: Aflatoxins; Animals; Blood Proteins; Body Weight; Chickens; Chlortetracycline; Diet; Kinetics; Lipids; Liver; Male; Meat; Metabolic Clearance Rate; Organ Size

Enteric bacteria isolated from feedlot heifers treated with tetracyclines (TET) were examined for resistance to TET and ampicillin. The effects of feeding (45 days) therapeutic and subtherapeutic quantities of chlortetracycline (CTC) and the injection of therapeutic doses of oxytetracycline (3 daily doses) were compared. Performance data from the 45-day trial did not identify an antibiotic effect on average daily gain, although cattle fed subtherapeutic quantities of CTC showed improved feed efficiency. Bacterial resistance to TET was increased in the heifers given the therapeutic and subtherapeutic quantities of CTC in the ration. However, an increase in resistance to ampicillin did not occur. Oxytetracycline injections had a short-term effect, increasing the number of resistant organisms only during the week of drug administration.

Topics: Ampicillin; Animals; Body Weight; Cattle; Chlortetracycline; Enterobacteriaceae; Feces; Female; Oxytetracycline; Penicillin Resistance; Tetracyclines

Plasma and tissue concentration and pharmacokinetics of chlortetracycline (CTC) was determined in milk-fed and conventionally fed Holstein calves. A two-compartment open model was used after a single intravenous dose (11 mg CTC/kg body weight). There were no significant differences between dietary treatments. The drug was rapidly distributed from plasma into the peripheral compartment but was slowly eliminated, with detectable concentration of CTC continuing for 72 h after dosing. A single-compartment model was used after a single oral dose (22 mg CTC/kg body weight). All but four of the kinetic parameters were significantly different for the two dietary treatments. Milk-fed calves had a larger area under the plasma level curve, a larger fraction of the dose absorbed, a smaller volume of distribution and a smaller overall body clearance rate. Estimated recovery of CTC in the urine of the milk-fed calves was greater, regardless of route of administration. The concentration of CTC in tissues following an oral dose was greatest in kidney, followed by liver, heart, skeletal muscle, spleen and brain. Tissue depletion of CTC closely paralleled the decline in plasma concentration.

Topics: Administration, Oral; Animal Feed; Animals; Body Weight; Cattle; Chlortetracycline; Diet; Food, Formulated; Injections, Intravenous; Male; Milk; Tissue Distribution

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

Holstein calves were maintained on a subtherapeutic dose of chlortetracycline to determine if an oxytetracycline therapy, given after a Salmonella typhimurium challenge, would be compromised by the previous subtherapy. Two of the four groups of seven calves were maintained on a subtherapeutic amount of chlortetracycline. All calves then were challenged with Salmonella typhimurium, and with the onset of clinical symptoms one group with and one group without subtherapy were given a therapeutic dose of oxytetracycline. The two groups receiving a therapeutic dosage of oxytetracycline had the most quickly declining body temperatures and the highest average body weights post-challenge. Two calves died in the group receiving no antibiotic treatments, and one calf died in the group receiving only the subtherapeutic treatment. There were no differences in postchallenge body temperatures or body weight changes between subtherapeutic and nonsubtherapeutic groups of calves. The conclusion was that the subtherapeutic dosing of chlortetracycline did not affect the therapeutic treatment effects of oxytetracycline after a Salmonella typhimurium challenge.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Chlortetracycline; Female; Oxytetracycline; Salmonella Infections, Animal; Salmonella typhimurium

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

Experiments were conducted to determine the sequence and reliability of appearance of key signs of vitamin A deficiency. Rapid and essentially synchronous vitamin A deficiency was induced by the withdrawal of retinoic acid from mature (190--210 g) stringently vitamin A-deficient male rats reared by feeding early growth plateau (60--70 g) vitamin A-deprived rats diets first supplemented with and then lacking in 2 micrograms retinoic acid per gram diet in repeating 18 day:10 day supplementation:deprivation cycles. Growth was depressed within 1 to 2 days of the withdrawal of retinoic aicid whether animals were force-fed or were fed ad libitum. Similar patterns were obtained when animals were fed 5 or 10 micrograms retinoic acid per gram diet. Appetite was depressed (1--2 days) whether animals were fed 18% casein diets, or were given 10% dextrose drinking solutions only. Decreased food intake was not due to impaired taste function or to poor palatability of the deficient diet. Bilateral electrolytic lesions in the ventromedial nucleus of the hypothalamus or anterior prepyriform cortex failed to prevent or to delay loss of appetite. Supplementation with antibiotics decreased body weight losses in the late stages of deficiency and increased survival time. Other signs of deficiency (days until onset following retinoate withdrawal; percent incidence) were: decreased intestinal goblet cell numbers (2--3; 80), decreased pilocarpine induced salivation (6--8; 80), tracheal metaplasia (6--8; 80), transient periocular porphyria (6--8; 60), altered salivary gland morphology (9--10; 80), decreased stomach emptying in force-fed animals (12; 70), twisting (12; 5) and leg crippling (12; 5). We conclude that the sequence of appearance of individual signs of deficiency following the induction of synchronous vitamin A deficiency is highly reproducible, and that the more general use of synchronously deficient animals would materially assist studies of cause-effect relationships in vitamin A deficiency.

Topics: Animals; Appetite; Body Weight; Chlortetracycline; Hypothalamus; Male; Rats; Taste; Tretinoin; Vitamin A Deficiency

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Body Weight; Chlortetracycline; Cyclic N-Oxides; Quinoxalines; Swine

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

Six groups of swine (85 animals) were fed a combination of antimicrobial drugs (sulfamethazine 100 g/ton, chlortetracycline 100 g/ton and penicillin 50 g/ton). After two weeks the antimicronial drugs were removed from the diet of two groups (28 animals). These swine were compared to four groups fed the medicated diet to determine the effect of duration of treatment and degree of animal isolation on the persistence of resistance in lactose-fermenting enteric organisms. The degree of resistance to penicillin, oxytetracycline, dihydrostreptomycin and neomycin as determined by minimum inhibitory concentrations and the incidence of resistant organisms were examined during and after antibiotic feedings. Ninety-two percent or greater of all isolates tested during and after treatment had minimum inhibitory concentrations for oxytetracycline of greater than 100 mug/ml. Thirty-two weeks after cessation of dietary antibiotic, resistance to oxytetracycline and dihydrostreptomycin remained at 100% and 89% respectively. Variation in degree of contact between swine receiving medicated feed and those receiving nonmedicated feed was not sufficient to reduce the incidence of resistance to oxytetracycline or dihydrostreptomycin in all animals. Factors influencing persistence of resistant enteric organisms are discussed. Addition of the antimicrobials to the ration resulted in significantly greater weight gains for treated animals than for the controls but did not alter feed conversion.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Bacteria; Body Weight; Chlortetracycline; Dihydrostreptomycin Sulfate; Fermentation; Intestines; Lactose; Neomycin; Oxytetracycline; Penicillin Resistance; Penicillins; Sulfamethazine; Swine

Two experiments were performed to study the effect of dietary antibiotics on percent daily weight change, mortality and gross cecal pathology in chickens during the critical phase of Eimeria tenella infection. In the first experiment, chickens were continuously fed ration containing thiopeptin, 2 mg/kg.; bacitracin, 20 mg./kg.; penicillin, 12 mg./kg.; or chlortetracycline, 22 mg./kg. One day after antibiotic fed was given, each bird received an oral inoculation of 30,000 sporulated oocyts. In the second experiment, chickens were consecutively fed ration containing amprolium plus ethopabate, 125 plus 8 mg./kg., and a combination of the coccidiostat and one of 4 antibiotics; thiopeptin, bacitracin, penicillin, or chloretracycline. One day after medicated feed was given, birds were each given an oral inoculation of 30,000 amprolium plus ethopabate-resistant E. tenella oocysts. The experiments were terminated 7 days after coccidia exposure. In both experiments, E. tenella infection resulted in depression in all birds of infected groups. Average percent weight change of infected birds was significantly lower than that of uninfected unmedicated control between 4 and 5 days after infection. Significantly greater number of birds died of cecal coccidiosis in group fed dietary bacitracin than that of other infected groups. Dietary antibiotics did not reduce gross cecal lesions.

Topics: Administration, Oral; Aminobenzoates; Amprolium; Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Bacitracin; Body Weight; Chickens; Chlortetracycline; Coccidiosis; Drug Resistance; Eimeria; Male; Penicillin G Procaine; Peptides; Poultry Diseases

1. Conventional or gnotobiotic chicks, when injected from 1 d to 3 weeks of age with adrenocorticotrophic hormone (120IU/kg, three times weekly), showed a depressed growth rate, adrenal hypertrophy and depletion of cholesterol form the adrenal glands. 2. Feeding a diet supplemented with aureomycin (10 mg/kg) did not have any consistent ameliorating effect on the response of the stressed bird as judged by the above parameters. 3. It was found that treating germfree chicks with five daily injections of sterile milk on days 3 to 7 did not depress growth rate at any time, nor could differences in adrenal size or cholesterol stores be detected at the end of the 21-d experimental period. The responses were not modified by feeding an aureomycin-supplemented diet.

Topics: Administration, Oral; Adrenal Glands; Adrenocorticotropic Hormone; Animal Feed; Animals; Body Weight; Chickens; Chlortetracycline; Cholesterol; Germ-Free Life; Milk; Organ Size; Stress, Physiological

Topics: Animals; Body Weight; Chlortetracycline; Cholesterol; Coleoptera; Diet; Larva; Metamorphosis, Biological; Rickettsiaceae; Time Factors; Triglycerides; Vitamins; Zea mays

The effect of tylosine and sulphadimidine, chlortetracycline, and bacitracin in feed was studied in 1275 piglets from 120 litters; the values obtained were compared with the control group given no antibiotics. Three Tylan injections were applied to a half of the animals on the 2nd, 5th, and 28th day after birth. The Tylan program did not lead to any significant reduction of piglet mortality before the 50th day of life. In neither of the groups did Tylan injections reduce mortality at the level of statistical significance. From the age of 56 days, the Tylan-application program provides statistically significant weight gains, as compared with other groups. The group with Czechoslovak antibiotics had the same weight as the group fed without antibiotics. The occurrence of pathological and anatomic findings on lungs showed no statistically significant differences in the two groups. The presence of tylosine in blood could not be ascertained after the oral application of even much higher doses than those used in the Tylan-application program. Small incidence of rhinitis does not allow for drawing any conclusions concerning the effects of Tylan.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Bacitracin; Body Weight; Chlortetracycline; Leucomycins; Regression Analysis; Sulfonamides; Swine

Topics: Aminoglycosides; Animal Feed; Animals; Anti-Bacterial Agents; Body Weight; Cattle; Cattle Diseases; Chlortetracycline; Edible Grain; Lactones; Liver Abscess; Male; Zea mays

Six experiments were carried out to study the effect of feed additive antibiotics on body weight, mortality and oocyst production in chickens infected with coccidiostat-susceptible or -resistant strain of E. tenella. Levels of antibiotic and coccidiostat in fed (mg./kg.) were: thiopeptin, 2; zinc bacitracin, 20; penicillin, 12; chlortetracycline, 22; amprolium plus ethopabate, 125 plus 8; clopidol, 125. All experiments included 7 groups; 2 of these groups were uninfected and infected controls, and the 5 remaining groups were all infected and given diet containing antibiotic, amprolium plus ethopabate, antibiotic and amprolium plus ethopabate, clopidol, or antibiotic and clopidol. Chickens in each group were fed respective diet beginning one day prior to coccidia exposure. In two experiments, infection with a coccidiostat-susceptible strain resulted in severe clinical coccidiosis in chickens on the basal ration and on thiopeptin-diet, but dietary thiopeptin prompted recovery of body weight. In one experiment where chickens were infected with a strain resistant to amprolium plus ethopabate and clopidol, birds on dietary thiopeptin attained higher body weight than birds on the basal ration. In three experiments when a strain resistant to amprolium plus ethopabate was inoculated, birds given the basal ration, bacitracin, penicillin, chlortetracycline, or amprolium plus ethopabate diet developed cecal coccidiosis. Chickens on ration containing antibiotic alone attained higher body weight than chickens on the basal ration. Combination of antibiotic and amprolium plus ethopabate resulted in higher weight attained than amprolium plus ethopabate alone. Clopidol suppressed development of coccidiosis, and the combination of antibiotic and clopidol resulted in higher gains than in clopidol alone.

Topics: Aminobenzoates; Amprolium; Animal Feed; Animals; Anti-Bacterial Agents; Bacitracin; Body Weight; Chickens; Chlortetracycline; Clopidol; Coccidiosis; Feces; Female; Food Additives; Male; Penicillin G Procaine; Peptides; Poultry Diseases

A series of 3 experiments was conducted on 3-day-old, single combed, white Leghorn cockerels for the purpose of studying the mechanism of aureomycin-promoting effects in body weight gain of chicks. In each experiment, 3 groups of chicks were fed for 4 weeks respectively on 1) basal ration, 2) basal ration supplemented with 25 ppm aureomycin and 3) basal ration with different amounts of alkali-decomposed aureomycin. At the end of each experimentation, 131I was injected intraperitoneally into the chicks. One hour later, the chicks were sacrificed by decapitation. The thyroid glands were removed immediately and weighed. The glands were prepared for radioactivity determination by the TraceLab multi/matic 501 counting system. The percentage of 131I uptake of the injected dose per mg thyroid gland was ascertained. The results indicated a significant increase of thyroid indices (mg thyroid gland per 100 gm body weight) after feeding aureomycin or decomposed aureomycin. The radioactivity determinations showed that the thyroid 131I uptake of the experimentals, especially those fed aureomycin, was significantly smaller than that of the controls. The present results, therefore, are in accord with the hypothesis of antithyroid effect of aureomycin propsed by Calesnick et al. in 1954. Furthermore, it suggests that such goitrogenic action might have resulted from aureomycin degraded under the influences of alkaline medium of the intestines and high body temperature of the chick. In addition to the functional change of the thyroid gland, aureomycin or decomposed aureomycin also promoted body weight gain and an increase in fat content in the chicks. These results suggest that body weight-promoting effect of aureomycin in animals may be attributable to an alteration of thyroid function which, in some way, is related to the products resulting from the degradation of the antibiotic in vivo.

Topics: Adipose Tissue; Animals; Body Weight; Bone Development; Chickens; Chlortetracycline; Iodine; Male; Organ Size; Thyroid Gland

Topics: Adenine; Amino Acids; Animal Nutritional Physiological Phenomena; Animals; Body Water; Body Weight; Chickens; Chlortetracycline; Deficiency Diseases; Diet; Glutamates; Male; Nitrogen; Proteins; Purines; Uracil; Urea; Uric Acid; Xanthines

Topics: Administration, Oral; Animal Feed; Animals; Anti-Bacterial Agents; Body Temperature; Body Weight; California; Chlortetracycline; Female; Lung; Male; Pneumonia; Sheep; Sheep Diseases; Sulfamethazine; Weaning

Topics: Administration, Oral; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Animals, Newborn; Body Weight; Chlortetracycline; Diet; Dietary Proteins; Edible Grain; Female; Glycine max; Lactation; Penicillins; Pregnancy; Reproduction; Sulfamethazine; Swine; Weaning

Topics: Animals; Anti-Bacterial Agents; Bacitracin; Body Weight; Chloramphenicol; Chlortetracycline; Embryo, Nonmammalian; Enteritis; Intestines; Microbial Sensitivity Tests; Neomycin; Oxytetracycline; Penicillins; Poultry Diseases; Staining and Labeling; Streptomycin; Turkeys; Viruses

Antimicrobial agents were added to the feed of swine for three weeks to determine the interrelationships of potentially pathogenic agents in the nasal tract, turbinate atrophy and weight gains. Bordetella bronchiseptica was not isolated from the groups fed the combination of chlortetracycline, penicillin and sulfamethazine. B. bronchiseptica was found in some pigs after the feeding trail, but this organism was not significantly associated with turbinate atrophy at the time of slaughter.Mycoplasma hyorhinis was not found in the nasal passages of the pigs that received feed containing high concentration chlortetracycline but was found in pigs that received other diets. Hemophilus suis was not significantly reduced by any of the treatments used. The organisms studied in the pigs were not isolated from the personnel handling the pigs.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Body Weight; Bordetella; Chlortetracycline; Diet; Food Additives; Haemophilus; Mycoplasma; Nose; Oleandomycin; Oxytetracycline; Pasteurella; Penicillin G Procaine; Streptococcus; Streptomycin; Sulfamethazine; Swine

Topics: Administration, Oral; Animal Feed; Animals; Body Weight; Cattle; Chlortetracycline; Food Additives; Time Factors

Topics: Animals; Body Weight; Cattle; Chlortetracycline; Choline; Dietary Fats; Drug Combinations; Fatty Liver; Folic Acid; Inositol; Lipids; Lipotropic Agents; Liver; Liver Extracts; Male; Organ Size; Rats; Vitamin B 12

Topics: Animals; Anti-Bacterial Agents; Body Weight; Chlortetracycline; Clostridium Infections; Drug Synergism; Enterotoxemia; Feeding Behavior; Food Additives; Sheep; Sheep Diseases; Sulfamethazine

Topics: Animals; Basal Metabolism; Body Weight; Chickens; Chlortetracycline; Feeding Behavior; Food Additives; Male; Time Factors

Topics: Administration, Oral; Agriculture; Analysis of Variance; Animals; Body Weight; Cattle; Cattle Diseases; Chlortetracycline; Diethylstilbestrol; Respiratory Tract Infections; Sulfamethazine

Topics: Amino Acids; Animals; Body Weight; Chlortetracycline; Cholesterol; Diet; Insecta; Larva; Lipid Metabolism; Time Factors

Topics: Analysis of Variance; Animal Feed; Animals; Body Weight; Carrier State; Chlortetracycline; Chronic Disease; Lung; Penicillins; Pneumonia; Sex Factors; Sulfamethazine; Swine; Swine Diseases

Topics: Anemia; Body Weight; Chloramphenicol; Chlortetracycline; Cough; Cystic Fibrosis; Diabetes Mellitus, Type 1; Diet Therapy; Feces; Humans; Hunger; Hypoproteinemia; Infant; Infant, Newborn; Intestinal Obstruction; Meconium; Pancreatic Juice; Pancreatin; Physical Therapy Modalities; Prognosis; Rectal Prolapse; Sweat; Tooth Discoloration; Vomiting

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Body Weight; Cattle; Chlortetracycline; Consumer Behavior; Diethylstilbestrol

Topics: Albumins; Aminopyrine; Animals; Body Weight; Chlortetracycline; Cytochromes; Depression, Chemical; Hexobarbital; Injections, Intraperitoneal; Liver; Magnesium; Male; Microsomes; NADP; Organ Size; Phenobarbital; Proteins; Rats; Sleep

Topics: Animals; Antigens; Body Weight; Chickens; Chlortetracycline

Topics: Animals; Body Weight; Cecum; Cell Membrane Permeability; Chlortetracycline; Colorimetry; Fasting; Feces; Glucose; Guinea Pigs; Histidine; Intestinal Absorption; Intestinal Mucosa; Intestine, Small; Lipid Metabolism; Male; Organ Size; Penicillins

Topics: Acute Disease; Animals; Blood Urea Nitrogen; Body Weight; Chlortetracycline; Cholesterol; Choline Deficiency; Cystine; Diet; Feces; Germ-Free Life; Hematocrit; Kidney Diseases; Lipid Metabolism; Liver; Male; Neomycin; Rats; Stimulation, Chemical; Vitamin B 12

Topics: Animals; Body Weight; Chlortetracycline; Drug Antagonism; Flavins; Kidney; Liver; Male; Organ Size; Rats; Riboflavin Deficiency; Time Factors

Topics: Animals; Body Weight; Chlortetracycline; Female; Germ-Free Life; Histamine; Intestinal Mucosa; Intestines; Male; Mice; Organ Size; Serotonin; Tetracycline

Topics: Abortion, Spontaneous; Animals; Animals, Newborn; Body Weight; Chlortetracycline; Female; Mice; Oxytetracycline; Pregnancy; Pregnancy, Animal; Tetracycline

Topics: Animal Feed; Animals; Body Weight; Chlortetracycline; Diet; Seasons; Swine

Topics: Alanine Transaminase; Animals; Arginase; Aspartate Aminotransferases; Blood Urea Nitrogen; Body Weight; Chlortetracycline; Cholesterol; Fasting; Fatty Liver; Female; Germ-Free Life; Glutamate Dehydrogenase; Glycerides; Lipids; Liver; Male; Mice; Organ Size; Phospholipids; Proteins; Urease; Water

Topics: Animals; Body Weight; Chlortetracycline; Esterases; Fasting; Fatty Liver; Liver; Male; Mice; Organ Size; Staining and Labeling; Subcellular Fractions

Topics: Ammonia; Animals; Body Weight; Chlortetracycline; Diet; Digestive System; Growth; Intestinal Absorption; Intestinal Mucosa; Ion Exchange Resins; Male; Rats; Urea

Topics: Animals; Bile Acids and Salts; Body Weight; Chlortetracycline; Diet; Growth; Rats; Urea

Topics: Body Weight; Chlortetracycline; Fertility; Growth; Pharmacology; Rats; Research

Topics: Body Weight; Chlortetracycline; Hydrolysis; Intestines; Isoniazid; Metabolism; Pharmacology; Rats; Research; Urea; Vitamin A; Weight Gain

Topics: Anemia; Animals; Blood Cell Count; Body Weight; Cattle; Chlortetracycline; Colostrum; Female; Hemoglobins; Iron; Metabolism; Milk; Nitrogen; Nutritional Physiological Phenomena; Nutritional Sciences; Pharmacology; Pregnancy; Research; Vitamin A

Topics: Alcohols; Animals; Blood; Body Temperature; Body Weight; Chloramphenicol; Chlortetracycline; Creatine; Creatinine; Dogs; Hematopoiesis; Iron; Leukopenia; Pathology; Peroxides; Pharmacology; Phosphates; Radiation Injuries; Radiation Injuries, Experimental; Radiation-Protective Agents; Research

Topics: Animals; Anti-Bacterial Agents; Body Weight; Chickens; Chlortetracycline; Cholesterol; Humans; Lipids; Neomycin; Oxytetracycline; Penicillins; Sulfathiazoles

Topics: Administration, Oral; Benzoates; Body Weight; Body Weights and Measures; Chlortetracycline; Rats; Research; Sodium Benzoate; Toxicology

Topics: Adrenalectomy; Animals; Biological Phenomena; Body Weight; Body Weights and Measures; Chlortetracycline; Growth; Physiological Phenomena; Rats

Topics: Amino Acids; Animals; Anti-Bacterial Agents; Antibiotics, Antitubercular; Body Composition; Body Weight; Body Weights and Measures; Chlortetracycline; Rats

Topics: Animals; Biological Phenomena; Body Weight; Body Weights and Measures; Chlortetracycline; Growth; Physiological Phenomena; Rats

Topics: Animals; Body Weight; Chlortetracycline; Growth; Proteins; Rats; Research

Topics: Animals; Body Composition; Body Weight; Chlortetracycline; Copper; Copper Sulfate; Lecithins; Phosphatidylcholines; Rats; Tannins; Weight Gain

Topics: Animals; Body Weight; Body Weights and Measures; Chlortetracycline; Diabetes Mellitus, Experimental; Rats

Topics: Animals; Body Weight; Body Weights and Measures; Chlortetracycline; Guinea Pigs

Topics: Animals; Anti-Bacterial Agents; Antibiotics, Antitubercular; Body Weight; Chloramphenicol; Chlortetracycline; Contrast Media; Dermatologic Agents; Liver; Mice; Penicillins; Spleen; Streptomycin; Thorium Dioxide