Milk productivity of Holstein and black-and-white cows under heat stress

Abstract

Poultry farming face’s objective challenges every day to ensure high viability of poultry in the context of industry intensification. In this work, an assessment was made of the influence of the domestic immunomodulatory drug "Azoxivet" on the postvaccination level of antibodies of broiler chickens of the "Ross-308" cross to the pathogens of Newcastle disease, infectious bronchitis of chickens and infectious bursal disease, as well as congenital non-specific factors of immune protection. The experiment was conducted in the vivarium of the Moscow State Academy of Veterinary Medicine and Biotechnology – the K.I. Skryabin Veterinary Academy. Broiler chickens were raised on the floor for 35 days. The dynamics of the increase in specific titers to Newcastle disease was higher in the experimental group – by 55.78% at the age of 28 days, by 28.44% at 33 days and by 10.49% at the end of the experiment. By day 35 of the experiment, the titer to infectious bronchitis of chickens also increased by 15.88%, but decreased by 11.62% to infectious bursal disease. According to the results of the experiment, a change in the indicators of nonspecific protection was noted. When testing for ELISA, the average titer against infectious bronchitis of chickens by the end of the experiment was higher in the experimental group than in the control - by 15.88%. However, against infectious bursal disease, the group receiving "Azoxivet" had lower antibody titers - by 11.62%. We noted that, with a decrease in BASK - by 3.69% and LASK - by 13.35%, FA increased - by 14.25%, FI - by 1.05% and FC - by 0.91%, compared to the control group. Based on the conducted research, we recommend the use of "Azoxivet" at a dose of 0.3 mg/kg of live weight of the bird.