chlortetracycline and Poultry-Diseases

Mycoplasma gallisepticum (M. gallisepticum) remains one of the most important diseases in poultry production. Controlling the impact of the disease is done by eradication of positive breeder flocks or by vaccination and medication. A widely used molecule in medication programs is tiamulin, a pleuromutilin antibiotic. Since recent data on the in vivo efficacy of this molecule are scarce, 2 challenge studies were conducted using a recently isolated M. gallisepticum strain belonging to the wildtype population with regard to its tiamulin and tetracycline minimum inhibitory concentration (MIC). In the first challenge study, the dose rate of tiamulin was tested. For this, broilers were infected with M. gallisepticum and treated with 10 mg or 25 mg tiamulin hydrogen fumarate (hf)/kg body weight (BW) for 5 successive days. In a second challenge study, the dose rate of tiamulin combined with chlortetracycline was tested. For this, broilers were infected with M. gallisepticum and treated with 6.25 mg tiamulin hf/18.75 mg chlortetracycline hydrochloride (hcl)/kg BW or 12.5 mg tiamulin hf/37.5 mg chlortetracycline hcl/kg BW for 5 successive days. Clinical scoring of respiratory signs, macroscopic scoring of respiratory tract lesions, M. gallisepticum isolation from the respiratory organs, weight gain, and mortality were the monitored efficacy parameters. The first study demonstrated that a 5-day 10 mg/kg BW tiamulin hf treatment provided significant protection against the M. gallisepticum infection. However, since the 5-day 25 mg/kg BW group was significantly better than the 10 mg/kg BW for reducing the post-treatment clinical signs and the M. gallisepticum numbers in the respiratory organs, the 25 mg/kg BW treatment is recommended for clinical M. gallisepticum infections. In the second study, the combined 12.5 mg tiamulin hf/37.5 mg chlortetracycline hcl/kg BW resulted in a significant reduction of the severity of clinical respiratory disease post treatment and a significant reduction of the M. gallisepticum numbers in the respiratory tract.

Topics: Animals; Anti-Bacterial Agents; Chickens; Chlortetracycline; Diterpenes; Dose-Response Relationship, Drug; Drug Combinations; Drug Therapy, Combination; Mycoplasma gallisepticum; Mycoplasma Infections; Poultry Diseases

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

One hundred seventy-eight mycoplasma strains isolated from South African poultry flocks between 2003 and 2015 were identified by full-genome sequencing and phylogenetic analysis of the 16S rRNA gene and were classified as follows:

Topics: Animals; Anti-Bacterial Agents; Chickens; Chlortetracycline; Diterpenes; Drug Resistance, Multiple, Bacterial; Microbial Sensitivity Tests; Mycoplasma; Mycoplasma Infections; Phylogeny; Poultry Diseases; South Africa; Tylosin

Avian cholera is a significant disease of domestic and wild birds caused by the bacterium Pasteurella multocida (PM). In poultry, a major source of PM infection is chronic carriers, domestic birds that have become infected and recovered or had subclinical infections. Although outbreaks of avian cholera in ring-necked pheasants (Phasianus colchicus) have been reported, the potential for chronic carriers is unknown. To address this, we conducted surveillance for PM in a flock of captive ring-necked pheasants after an outbreak of avian cholera that responded positively to antibiotic treatment based on resolution of morbidity and mortality. At approximately 1 mo after antibiotic treatment, oropharyngeal swabs were collected from 300 pheasants (out of a total population of ~2300) in a single winter holding pen. All samples were tested for PM through routine aerobic bacterial culture, but none of the samples were positive. In addition, there were no additional outbreaks within this infected pen over the subsequent months. These data provide preliminary evidence to suggest that pheasants that respond to antibiotic therapy may be less likely to become chronic carriers of PM than other poultry species, such as chickens (Gallus domesticus). However, due to marked phenotypic and biologic differences between PM strains, additional studies are needed to further support or refute these findings and better understand avian cholera in this species.

Topics: Animals; Anti-Bacterial Agents; Asymptomatic Infections; Chlortetracycline; Epidemiological Monitoring; Galliformes; Oropharynx; Pasteurella Infections; Pasteurella multocida; Pennsylvania; Poultry Diseases; Treatment Outcome

The influence of specific and non-specific antibiotic pressure on in vivo spread of macrolide-lincosamide-streptogramin B (MLSB) resistance was evaluated in this study. Chickens repeatedly inoculated with Enterococcus faecalis harbouring the plasmid pAMβ1 carrying the erm(B) gene were perorally treated for one week with tylosin, lincomycin (both specific antibiotic pressure) and chlortetracycline (non-specific antibiotic pressure). Antibiotic non-treated but E. faecalis inoculated chickens served as a control. To quantify the erm(B) gene and characterise intestinal microflora, faecal DNA was analysed by qPCR and 454-pyrosequencing. Under the pressure of antibiotics, a significant increase in erm(B) was observed by qPCR. However, at the final stage of the experiment, an increase in erm(B) was also observed in two out of five non-treated chickens. In chickens treated with tylosin and chlortetracycline, the increase in erm(B) was accompanied by an increase in enterococci. However, E. faecalis was at the limit of detection in all animals. This suggests that the erm(B) gene spread among the gut microbiota other than E. faecalis. Pyrosequencing results indicated that, depending on the particular antibiotic pressure, different bacteria could be responsible for the spread of MLSB resistance. Different species of MLSB-resistant enterococci and streptococci were isolated from cloacal swabs during and after the treatment. PFGE analysis of MLSB-resistant enterococci revealed four clones, all differing from the challenge strain. All of the MLSB-resistant isolates harboured a plasmid of the same size as pAMβ1. This study has shown that MLSB resistance may spread within the gut microbiota under specific and non-specific pressure and even in the absence of any antimicrobial pressure. Finally, depending on the particular antibiotic pressure, different bacterial species seems to be involved in the spread of MLSB resistance.

Topics: Animals; Anti-Bacterial Agents; Base Sequence; Chickens; Chlortetracycline; DNA Primers; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Enterococcus faecalis; Feces; Gene Transfer, Horizontal; Gram-Positive Bacterial Infections; Lincosamides; Macrolides; Methyltransferases; Microbial Sensitivity Tests; Molecular Sequence Data; Plasmids; Polymerase Chain Reaction; Poultry Diseases; Sequence Analysis, DNA; Species Specificity; Statistics, Nonparametric; Streptogramin B; Tylosin

The efficacy of doxycycline was investigated in two sets of experiments. In the first experiment 40, in the second experiment 60, hence altogether 100 five-week-old Ross broilers of both sexes were used. The birds were randomly allocated into groups (A and B in experiment 1; A, B and C in experiment 2) of 20 birds in each. All birds were infected intramuscularly with approx. 2 x 10(3) colony forming units of Pasteurella multocida strain X-73 (serotype A:1). Birds in groups A were non-medicated controls. Chickens in groups B were given doxycycline via the drinking water at a dose of 10 mg/kg body weight for 5 days, while group C was treated with chlortetracycline at a dose of 20 mg/kg body weight for 5 days. The trial lasted for 9 days, then the surviving chickens were sacrificed. Clinical symptoms, number of deaths, post mortem lesions and bacteriological findings were recorded using a special score system. Acute fowl cholera developed in broilers within a few hours after infection, as evidenced by the clinical symptoms, the high mortality rate (90% of the birds died within 4 days after infection), the pathological lesions and the recovery of P. multocida from the challenged birds. Doxycycline reduced the number of deaths (30% and 5% of birds died in experiments 1 and 2, respectively) and the severity of the clinical symptoms, and P. multocida could be re-isolated only from one of the survivors. In contrast, chlortetracycline slightly influenced the mortality; however, it delayed death and reduced the severity of clinical symptoms. These data indicate that doxycycline is highly effective for the treatment of experimental pasteurellosis in chickens.

Topics: Animals; Anti-Bacterial Agents; Chickens; Chlortetracycline; Colony Count, Microbial; Doxycycline; Female; Male; Microbial Sensitivity Tests; Pasteurella Infections; Pasteurella multocida; Poultry Diseases; Random Allocation

Using different variations of challenge, three trials were conducted to evaluate the efficacy of chlortetracycline in the control of chronic respiratory disease (CRD) caused by Escherichia coli and Mycoplasma gallisepticum. Experimentally infected birds were offered either food containing chlortetracycline at 300 ppm or water containing the drug at 120 mg litre-1. In each trial, medicated food and water were effective in the control of CRD as assessed by reduction in clinical signs, lower mortality and reduced severity of air sacculitis and other post mortem lesions. Weight gain was also improved by both forms of medication. M gallisepticum antibodies were demonstrated in surviving birds.

Topics: Air Sacs; Animals; Chickens; Chlortetracycline; Chronic Disease; Escherichia coli Infections; Mycoplasma Infections; Poultry Diseases; Respiratory Tract Infections; Specific Pathogen-Free Organisms; Weight Gain

Seven experiments were conducted to test the influence of dietary supplementary ascorbic acid on the development of tibial dyschondroplasia in broiler chickens. Ascorbic acid supplementation significantly reduced the incidence and number of birds with a large mass of cartilage in the tibia in the first experiment but not in the two subsequent experiments. Because environmental temperature, microbial infection, and vitamin D3 status had been reported in the literature to influence ascorbic acid metabolism in the chicken, experiments were conducted to see if these variables could influence supplemental ascorbic acid effects on development of tibial dyschondroplasia. Results of the experiments indicated that none of these factors influenced the effect of ascorbic acid on the development of tibial dyschondroplasia. The presence of vitamin D3 in the diet significantly influences the incidence of this disorder.

Topics: Animals; Ascorbic Acid; Chickens; Chlortetracycline; Cholecalciferol; Male; Osteochondrodysplasias; Poultry Diseases; Temperature; Vitamin D Deficiency; Weight Gain

A commercially available antibiotic and nutrient solution was prefed by gavage into the crops of newly hatched poults, which were then brooded under standard conditions of continuous lighting, 35-C temperatures, and ad libitum feed. Treated poults exhibited higher feed consumption, hematocrits, and total red blood cells during the week following the prefeeding regime. Prefeeding partially ameliorated the typically low hematological parameters that have been associated previously with early poult mortality. The results of this study suggest that prefeeding an antibiotic and nutrient solution significantly improves the welfare of poults during the 1st week after hatching.

Topics: Animals; Chlortetracycline; Erythrocyte Count; Erythrocyte Indices; Hematocrit; Intubation, Gastrointestinal; Male; Poultry Diseases; Turkeys; Vitamins

A physiologically based pharmacokinetic model was developed to describe the absorption and disposition of chlortetracyline (CTC) in the healthy and diseased (fowl cholera) turkey. The CTC was given (with and without citric acid) as an oral (15 mg/kg) or i.v. (1 mg/kg) dose. When minerals (0.3 g/L Ca2+, 0.1 g/L Mg2+) were dissolved in the bird's drinking water, the model indicated that the addition of citric acid (mass ratio of 10 citrate: 1 CTC) increased the fraction of dose absorbed from 0.06 to 0.16; once absorbed, the fractions of drug eliminated by renal excretion, biliary secretion, and chemical decomposition were 50, 46, and 4%, respectively. The presence of fowl cholera appeared to increase plasma levels by increasing the intestinal permeability and lowering the hepatic and/or renal clearance.

Topics: Administration, Oral; Animals; Chlortetracycline; Citrates; Citric Acid; Feces; Injections, Intravenous; Kinetics; Liver; Models, Biological; Pasteurella Infections; Phenolsulfonphthalein; Poultry Diseases; Turkeys

Swine from two herds with different histories of antibiotic exposure were fed diets containing 0 or 55 mg of chlortetracycline (CTC)/kg. One of five pigs in each herd-diet treatment group was infected orally with Escherichia coli strain BEL15R that was resistant to nalidixic acid (NA), chloramphenicol (C), streptomycin (S), sulfamethizole (TH) and tetracycline (TE). Effects of CTC on the quantity and duration of fecal shedding of E. coli BEL15R and on the transmission of strain BEL15R and its R-100 plasmid from infected pigs to uninfected pigs and chicks were determined. Quantity and duration of shedding were greater in infected antibiotic-herd pigs than in infected nonantibiotic-herd pigs. Feeding on CTC increased the duration of shedding in infected pigs from both herds. Strain BEL15R colonized and was shed in one uninfected antibiotic pig in each treatment group, but it did not colonize in any of the uninfected nonantibiotic-herd pigs or in the uninfected chicks. In vivo transfer of resistance to C, S, TH and TE occurred in the infected antibiotic-herd pigs but not in the infected nonantibiotic-herd pigs. Transfer of the R-100 plasmid occurred from the infected to the uninfected antibiotic-herd pigs and to the uninfected chicks housed near the antibiotic-herd pigs fed CTC, but not to the chicks housed with the antibiotic-herd pigs fed the control diet. No transfer of resistance occurred from the infected nonantibiotic-herd pigs fed either CTC or control diet.

Topics: Animals; Anti-Bacterial Agents; Chickens; Chlortetracycline; Escherichia coli; Escherichia coli Infections; Food Additives; Poultry Diseases; R Factors; Swine; Swine Diseases; Transformation, Bacterial

Plasma and tissue concentrations, following the oral administration of the antibiotic chlortetracycline (CTC) alone or with citric acid, were determined in healthy and infected (Pasteurella multocida) turkeys. The principal results were: 1) The dose (of CTC) versus plasma level relationship was nearly linear. 2) Addition of citric acid to an oral preparation produced significantly higher plasma levels when divalent cations Ca2+ (.3 g/liter) and Mg2+ (.1 g/liter) were present in the drinking water and dosage solution than when citric acid was omitted. 3) The concentration of CTC was considerably higher in the liver and kidney than in the muscle and brain. 4) Birds infected with P. multocida had significantly higher plasma levels than healthy birds. 5) Oral administration of CTC increased the survival rate of the birds infected with P. multocida.

Topics: Administration, Oral; Animals; Antacids; Chlortetracycline; Citrates; Citric Acid; Intestinal Absorption; Pasteurella Infections; Poultry Diseases; Turkeys

Topics: Ampicillin; Animal Feed; Animals; Anti-Bacterial Agents; Chickens; Chloramphenicol; Chlortetracycline; Escherichia coli; Escherichia coli Infections; Feces; Food Additives; Lactobacillus; Penicillin Resistance; Poultry Diseases

Three replicate trials were conducted with broiler male chicks to test the therapeutic efficacy of doxycycline, chlortetracycline and lincomycin-spectinomycin in water against an artifically induced Escherichia coli infection. Mortality, lesion scores (heart, liver and air sac), and performance data were the criteria in evaluating therapeutic efficacy of these drugs. Results indicated the therapeutic efficacy of doxycycline was greater than chlortetracycline and lincomycin-spectinomycin.

Topics: Administration, Oral; Animals; Chickens; Chlortetracycline; Doxycycline; Escherichia coli Infections; Lincomycin; Male; Poultry Diseases; Spectinomycin; Water

A six-week trial was conducted to determine if therapeutic use of chlortetracycline (CTC) would be affected by previous use of the same antibiotics at subtherapeutic levels in the feed. Results indicated therapeutic effect of CTC on mortality was not compromised by the previous use of the low level antibiotic.

Topics: Administration, Oral; Animal Feed; Animals; Chickens; Chlortetracycline; Poultry Diseases; Salmonella Infections, Animal; Salmonella typhimurium

Aureomycin fed at concentrations of 55, 110, and 220 mg./kg. of feed significantly (P less than 0.05) increased livability as compared to that of the nonmedicated exposed and increased average body wieght gained per turkey as compared to that of both the nonmedicated exposed and nonmedicated nonexposed turkeys. The increase in survival was proportional to the increase in concentration of Aureomycin in the feed. Turkeys were exposed, in the drinking water, to three isolates of Pasteurella multocida which had inclinations for localizing in the joints, lungs, and air spaces of the head. There were no carriers of P. multocida in either the medicated or nonmedicated turkeys three weeks after exposure.

Topics: Administration, Oral; Animal Feed; Animals; Arthritis, Infectious; Chlortetracycline; Drug Evaluation; Female; Head; Lung Diseases; Pasteurella Infections; Poultry Diseases; Turkeys

Two separate experiments were conducted to assess the shed rate and duration of shed of S . typhimurium organisms from turkey poults orally infected with chlortetracycline-sensitive S. typhimurium in relation to chloretetracycline (CTC) given in the feed at 0, growth promotant, subtherapeutic and therapeutic levels; the emergence of resistant S. typhimurium organisms in reference to the diet given; in vitro transfer of drug resistance from thses resistant S. typhimurium donor cultures to multiply-sensitive E. coli recipients; and phage type changes, is any, of these S. typhimurium isolates. The results showed that increasing CTC in the diet from 0 to the three levels of antibiotic supplementation, appeared to (a) reduce shed and duration of shed corresponding to each level used; (b) cause a minimal development of drug resistance and its transfer (usually at sub-therapeutic levels of CTC supplementation) for the duration of the experiment; and (c) induce phage type changes in some of the S. typhimurium isolates. These phage type changes question the validity of using phage typing as a tool in epidemiological investigations.

Topics: Administration, Oral; Animals; Cecum; Chlortetracycline; Cloaca; Drug Resistance, Microbial; Escherichia coli; Feces; Liver; Poultry Diseases; R Factors; Salmonella Infections, Animal; Salmonella typhimurium; Turkeys

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

Two experiments were performed ot investigate the effect of feed additive antibiotics on Clostridium perfringens and Enterobacteriaceae in the ceca of chickens infected with Eimeria tenella. In the first experiment, chickens were continuously fed rations containing thiopeptin, 2 mg./kg.; bacitracin, 20 mg./kg.; penicillin, 12 mg./kg.; or chlortetracycline, 22 mg./kg. One day after antibiotic feed was given, each bird received an oral inoculation of 30,000 E. tenella oocysts. The growth of C. perfringens was stimulated by the infection in unmedicated chickens. Dietary thiopeptin, bacitracin, penicillin, or chlortetracycline suppressed the number of C. perfringens recovered 5 and 7 days after infection. Enterobacteriaceae were increased by the infection, but dietary antibiotics did not reduce the increase. In the second experiment, chickens were given feed containing amprolium plus ethopabate, 125 plus 8 mg./kg., and a combination of the coccidiostat and one of 4 antibiotics: thiopeptin, bacitracin, penicillin, or chlortetracycline. Birds were each given an oral inoculation of 30,000 coccidiostat-resistant E. tenella oocysts. Infection resulted in an increase of C. perfringens in the unmedicated control and the coccidiostat-treated groups. Dietary thiopeptin, bacitracin, penicillin, or chlortetracycline reduced the number of C. perfringens found 5 and 7 days after infection. Counts of Enterobacteriaceae were increased by the infection, but dietary antibiotics did not suppress the increased counts. In both experiments, dietary administration of antibiotics did not reduce gross cecal lesions.

Topics: Aminobenzoates; Amprolium; Animal Feed; Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Bacitracin; Cecum; Chickens; Chlortetracycline; Clostridium perfringens; Coccidiosis; Enterobacteriaceae; Food Additives; Male; Penicillin G Procaine; Peptides; Poultry Diseases

Three avirulent and 5 slightly virulent for birds mutants of Salmonella enteritidis and Salmonella braenderup, resistant to streptomycin (S), chlorteracyclin (CT), and chloramphenicol (Ch) were used in the production of live vaccines. The latter were tested for immunogenicity on albino mice and birds. On the eighth and 15th day following vaccination the protein fractions in the blood serum of the birds were followed up through electrophoresis on agar gel, while the agglutinin titer was determined by means of test tube agglutination. The experimental results were mathematically processed with the use of statistical methods. All slightly virulent and resistant to antibiotics mutants showed strong immunogenic properties and gave protection (preventing death) to 76.2-81.82 per cent of the mice. Of the avirulent mutants one showed moderate virulence giving protection to 71.43 per cent of the animals. Tested on 110-day-old chickens the avirulent mutants gave protection to 80 per cent of them. The average titers of the blood serum antibodies of birds vaccinated with immunogenic mutants, and the average percent values of the gamma-globulin fractions were higher on the eighth than on the 15th day. The protein fractions showed changes in the albumin and the gamma-globulin. The rate of correlation between these indices, as shown by the coefficient of correlation, is high (rxy = - 0.843). In this case the negative value of rxy in the equation points to the negative link between the characters.

Topics: Animals; Anti-Bacterial Agents; Antibodies, Bacterial; Bacterial Vaccines; Chickens; Chloramphenicol; Chlortetracycline; Drug Evaluation, Preclinical; Drug Resistance, Microbial; Mice; Poultry Diseases; Salmonella; Salmonella enteritidis; Salmonella Infections, Animal; Streptomycin; Vaccination

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

Topics: Animals; Chickens; Chlortetracycline; Drug Evaluation; Ethylenediamines; Poultry Diseases; Spirochaetales Infections

Topics: Administration, Oral; Animals; Chickens; Chlortetracycline; Economics; Erythromycin; Leucomycins; Lincomycin; Meat; Poultry Diseases; Respiratory Tract Infections; Spectinomycin; Water

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Chickens; Chloramphenicol; Chlortetracycline; Furazolidone; Morpholines; Neomycin; Nitrofurans; Oxazoles; Oxytetracycline; Poultry Diseases; Rectum; Salmonella Infections, Animal; Salmonella typhimurium; Sulfamethazine

Topics: Animals; Chickens; Chlortetracycline; Drug Resistance, Microbial; Enterobacteriaceae; Enterobacteriaceae Infections; Escherichia coli; Extrachromosomal Inheritance; Mutation; Poultry Diseases; Salmonella; Salmonella Infections, Animal; Salmonella typhimurium; Virulence

Topics: Administration, Oral; Animals; Candida albicans; Candidiasis; Chlortetracycline; Feces; Glucose; Poultry Diseases; Turkeys

Topics: Animals; Anti-Bacterial Agents; Cell-Free System; Cells, Cultured; Chick Embryo; Chickens; Chlortetracycline; Dihydrostreptomycin Sulfate; Erythromycin; Fibroblasts; Herpesviridae; Marek Disease; Mycoplasma Infections; Neomycin; Oxytetracycline; Penicillin G; Poultry Diseases; Spectinomycin; Turkeys; Viral Plaque Assay; Viral Vaccines

Topics: Animals; Anti-Bacterial Agents; Chlortetracycline; Poultry Diseases; Vibrio Infections

Topics: Animals; Borrelia Infections; Chlortetracycline; Drug Combinations; Ethylenediamines; Penicillin G Benzathine; Poultry Diseases

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

Topics: Animals; Chickens; Chlortetracycline; Dihydrostreptomycin Sulfate; Haemophilus; Haemophilus Infections; Poultry Diseases; Pyridazines; Sulfamethazine; Sulfanilamides

Topics: Animals; Anti-Bacterial Agents; Chloramphenicol; Chlortetracycline; Dust; Escherichia coli; Microbial Sensitivity Tests; Neomycin; Penicillin Resistance; Penicillins; Poultry Diseases; Streptomycin

Topics: Animal Feed; Animals; Arsenic; Chickens; Chlortetracycline; Czechoslovakia; Drug Resistance, Microbial; Escherichia coli; Food Additives; Orthomyxoviridae Infections; Poultry Diseases; Research; Swine; Swine Diseases

Topics: Animals; Chick Embryo; Chickens; Chlortetracycline; Germ-Free Life; Mycoplasma Infections; Poultry Diseases; Respiratory Insufficiency; Respiratory Tract Infections; Viral Vaccines

Topics: Aflatoxins; Animal Feed; Animals; Anti-Bacterial Agents; Aspergillosis; Chickens; Chlortetracycline; Dietary Fats; Dietary Proteins; Poultry Diseases

Topics: Agglutination Tests; Animals; Anti-Bacterial Agents; Chickens; Chlortetracycline; Eye; Female; Male; Mycoplasma Infections; Phthalic Acids; Poultry Diseases; Trachea

Topics: Animals; Chickens; Chlortetracycline; Disease Outbreaks; Erysipelas; Liver; Myocardium; Poultry Diseases; Spleen

Topics: Animals; Chickens; Chlortetracycline; Poultry Diseases; Protozoan Infections; Protozoan Infections, Animal; Tetracycline

Topics: Animals; Chlortetracycline; Furazolidone; Poultry Diseases; Salmonella Infections, Animal; Ultraviolet Therapy

Topics: Animals; Chickens; Chlortetracycline; Oxytetracycline; Poultry Diseases; Protozoan Infections; Protozoan Infections, Animal; Tetracycline

Topics: Age Factors; Animal Diseases; Animals; Bronchopneumonia; Cattle; Chickens; Chlortetracycline; Delayed-Action Preparations; Ducks; Pasteurella Infections; Poultry Diseases; Rhinitis, Atrophic; Salmonella Infections, Animal; Swine; Swine Diseases; Tetracycline

Topics: Animals; Candidiasis; Chlortetracycline; Poultry Diseases; Turkeys; Vitamin A; Vitamin A Deficiency

Topics: Animals; Chickens; Chlorides; Chlortetracycline; Deficiency Diseases; Diet; Drug Synergism; Female; Poultry Diseases; Sulfates

Topics: Animals; Anti-Bacterial Agents; Chickens; Chlortetracycline; Dihydrostreptomycin Sulfate; Drug Synergism; Mycoplasma Infections; Oxytetracycline; Poultry Diseases; Sulfates; Tetracycline

Topics: Acridines; Animals; Antiprotozoal Agents; Apicomplexa; Chickens; Chlortetracycline; Oxytetracycline; Poultry Diseases; Protozoan Infections; Protozoan Infections, Animal; Tetracycline

Topics: Animals; Anti-Bacterial Agents; Chemical Phenomena; Chemistry, Physical; Chloroform; Chlortetracycline; Erythromycin; Ethyl Ethers; Mycoplasma; Poultry Diseases; Poxviridae; Temperature; Virus Physiological Phenomena; Viruses

Topics: Animals; Anti-Bacterial Agents; Chlortetracycline; Diet Therapy; Drug Resistance, Microbial; Furazolidone; Poultry Diseases; Salmonella Infections, Animal; Salmonella typhimurium

Topics: Animals; Calcium; Chlortetracycline; Pasteurella Infections; Poultry Diseases; Sodium; Sulfates

Topics: Animals; Chlortetracycline; Coccidiosis; Eimeria; Leucomycins; Oxytetracycline; Poultry Diseases

Topics: Animals; Anti-Bacterial Agents; Chickens; Chlortetracycline; Erythromycin; Mycoplasma; Mycoplasma gallisepticum; Mycoplasma Infections; Ovum; Pharmacology; Poultry Diseases; Research; Respiratory Tract Infections; Tylosin

Topics: Animals; Chickens; Chlortetracycline; Diet; Mycoplasma; Mycoplasma gallisepticum; Mycoplasma Infections; Ovum; Poultry Diseases; Research; Sulfates

Topics: Animals; Anti-Bacterial Agents; Blood Bactericidal Activity; Chlortetracycline; Immunity; Poultry Diseases; Salmonella; Salmonella Infections, Animal

Topics: Animals; Chickens; Chlortetracycline; Drug Resistance, Microbial; Male; Poultry Diseases; Salmonella; Salmonella Infections, Animal; Sulfonamides