The Effect of a Decrease in Relative Humidity During the Growing of Broilers on Immunity and Productivity Indicators

Abstract. An unsatisfactory microclimate in poultry premises contributes to damage in the form of a decrease in the average daily gain of broilers by 10 %. Purpose of research is to study the effect of relative humidity at the same temperature regime on the immunity and productivity of broilers of the Ross-308. Research methods. The experiment was carried out on broiler chickens of the cross Ross-308 up to 35 days of age. In group II, period 0–1 days of growing broilers, the relative humidity indicators were less than the lower limit of the norm by 10 %, in periods 5–7, 11–16, 20–22 and 26–35 days, the relative humidity indicators were less than the lower limit of the norm by 5 %. In group I, all indicators were recommended as recommended. The bactericidal activity of blood serum was determined by the method of I. M. Karput, lysozyme activity was determined by the nephelometric method according to V. G. Dorofeychuk. Results. As a result of the study, it was found that a decrease in the change in relative air humidity had a negative effect on immunity: the bactericidal and lysozyme activity of blood serum decreased. So, on the 21st day, the indicator of bactericidal activity of blood serum of broiler chickens in group II was lower by 14.2 % (P ≤ 0.05) compared to group I. At 3 weeks of age, the lysozyme activity of the blood serum of chickens of group II was lower by 14.3 % (P ≤ 0.05) compared to the control group. The productivity of birds also decreased to 13.70 % in relation to the control. Scientific novelty. For the first time, we have shown that a decrease in the indicators of relative air humidity at the content of Ross-308 cross broilers during the period of 0–1 days of cultivation by 10 % relative to the lower limit of the norm, during the periods of 5–7, 11–16, 20–22 and 26–35 days – by 5 %, subject to the recommended temperature parameters, has a negative effect on immunity.