Effects of two infectious bursal disease vaccine virus strains on hepatic microsomal enzyme activities in chickens.

The influence of two infectious bursal disease vaccines on the activities of hepatic microsomal enzymes aniline hydroxylase, ethylmorphine N-demethylase, NADPH-cytochrome c reductase, aryl sulphotransferase and p-nitrophenol UDP-glucuronyltransferase was investigated in chickens. The vaccines contained attenuated Winterfield 2512 and VMG-91 strains, respectively. The activities of enzymes were determined on postvaccination days 0, 2, 5 and 7. At the same time, post-mitochondrial supernatant, cytosolic and microsomal pellet protein concentrations were determined. As expected, the antibody titres against infectious bursal disease virus in the serum were increased in both tested groups in relation to each administered vaccine. Using RT-PCR, the presence of the VP2 gene fragment of virus in the liver of chicken was demonstrated 4 and 6 h after vaccination. The results of this study suggest that the two commercial vaccines modulate the activities of five enzymes tested, and that the two attenuated vaccines applied triggered induction and/or inhibition of phases I and II of biotransformation enzyme activities.

Marek's disease vaccination, with turkey herpesvirus, and enrofloxacin modulate the activities of hepatic microsomal enzymes in broiler chickens.

Chickens were vaccinated against Marek's disease intramuscularly at one day of age. Enrofloxacin was given ad libitum in the drinking water at concentrations of 50, 100 and 250 mg/L from 8 days to 13 days of age when the animals were killed and the activities of cytochrome P-450 enzymes in the liver were measured. Vaccinated non-treated chickens served as a positive control. A negative control group was neither vaccinated nor treated. Vaccination decreased the activity of aniline hydroxylase and ethylmorphine N-demethylase in the positive control group. Subsequent application of enrofloxacin in the lowest concentration (50 mg/L) decreased, while that given at the highest level (250 mg/L) significantly increased the activity of the same microsomal enzymes. Relative liver weights and concentrations of proteins in 9000 x g supernatant were not affected by vaccination or treatment.

Comparative efficacy of triclabendazole, nitroxynil and rafoxanide against immature and mature Fasciola hepatica in naturally infected cattle.

In two trials the fasciolicidal activities of triclabendazole, nitroxynil and rafoxanide were assessed in cattle naturally infected with predominantly immature stages of Fasciola hepatica. Tablets containing 900 mg triclabendazole were administered orally at a dose rate of 12 mg/kg bodyweight. Rafoxanide and nitroxynil were used at a dose rate of 10 mg/kg, rafoxanide being given orally and nitroxynil by subcutaneous injection. Based on faecal egg counts nine weeks after treatment the efficacies were calculated to be 100 per cent for triclabendazole and 95.0 per cent for nitroxynil in the first trial and 98.4 per cent for triclabendazole and 52.9 per cent for rafoxanide 15 weeks after treatment in the second trial. In the first trial five animals from each of the three groups were slaughtered and their fluke burdens counted. Compared with the untreated control group the reductions in the fluke burdens were 96.9 per cent in triclabendazole treated cattle and 76.4 per cent in the nitroxynil treated group.