Effects of tylosin injection in dry period on the performance and serum chemistry in dairy cows after parturition

To investigate the effects of tylosin injection in dairy cows at dry period on performance, milk composition and some blood parameters in subsequent lactation, 120 Holstein cows with a mean weight of 720±20Kg were used. Treatments were no tylosin (treatment 1; control group), injected 0.025 (treatment 2 low tylosin; LT) and 0.05 (treatment 3 high tylosin; HT) ml tylosin 20% per kg of body weight per day for 3 days after drying days. To determine biochemical parameters blood samples were collected at the drying day and 0, 7, 14, and 21 of lactation. Data of milk production and composition were collected for 4 months after calving. The difference between serum total protein concentration between treatments tended to be significant (P=0.051). Aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities were lower in the control group (P0.05). The incidence of mastitis in the groups receiving tylosin was significantly lower than the control group (P