Effect of tylosin tartrate on humoral immune responses in chickens

Physiological influence of tylosin tartrate overdose in vivo in rats

The aim of this study was to evaluate the physiological effects of tylosin in rats. Tylosin was administered orally to pubertal male and female rats at concentrations of 0.005, 0.2, 10 and 200 mg/kg b.w. for 6 weeks. The overall body and organ weights were recorded. Serum levels of immunoglobulins, haematological values, histopathological lesions in different organs, and gene expression profiles in pituitary glands were investigated. The mean platelet volume was increased, and the monocyte count was decreased significantly in both male and female rats treated with tylosin. Compared to the untreated control, alanine transaminase in both types of rats and total serum bilirubin in female rats were increased significantly with the administration of tylosin (200 mg/kg), however, lactate dehydrogenase in female rats was decreased. The levels of immunoglobulin M were reduced in both male and female rats but immunoglobulin G levels were significantly reduced only in female rats which were treated with tylosin. Cell proliferation- and adhesion-associated genes were expressed more but apoptosis gene expressions were decreased in the pituitary gland of tylosin-treated rats. In conclusion, this study revealed that the use of tylosin at therapeutic dosage is possibly not completely safe.

Effects of anticoccidial and antibiotic growth promoter programs on broiler performance and immune status

This study investigated the effects of various coccidiosis control programs in combination with antibiotic growth promoters (AGPs) on growth performance and host immune responses in broiler chickens. The coccidiosis programs that were investigated included in ovo coccidiosis vaccination (CVAC) with Inovocox or in-feed medication with diclazuril as Clinacox (CLIN) or salinomycin (SAL). The AGPs were virginiamycin or bacitracin methylene disalicylate plus roxarsone. As a negative control, chickens were non-vaccinated and fed with non-supplemented diets (NONE). All animals were exposed to used litter from a commercial broiler farm with confirmed contamination by Eimeria parasites to simulate in-field exposure to avian coccidiosis. Broiler body weights in the CVAC group were greater at 14 and 32 days of age, but not at day 42, compared with the NONE, CLIN, and SAL groups. At day 14, the SAL group showed decreased body weight and reduced ConA-stimulated spleen cell proliferation compared with the CLIN and SAL groups. In contrast, at days 34 and 43, splenocyte proliferation was greater in the CVAC and CLIN groups compared with the NONE and SAL groups. Lymphocyte subpopulations and cytokine mRNA expression levels in the intestine and spleen were also altered by the denoted treatments. Collectively, these results suggest that in ovo coccidiosis vaccination or coccidiostat drug medication programs in combination with AGPs influences chicken growth and immune status in an Eimeria-contaminated environment.