The Influence of Steroid Hormones of the Functional System Mother - Fetus on the Leukocyte Differential Count and on the Development of Predisposition to Bronchopneumonia in Calves During Neonatal Period

The aim of the work was to establish the level of steroid hormones in the blood serum of deep-pregnant cows and calves obtained from them and to establish correlations between hormonal and immunological parameters of the mothers and newborns. It was found that steroid hormones of the mother and the fetus take part in the development of fetoplacental insufficiency, weakening of the barrier function of the mucous membranes of the respiratory tract, stress-induced disruption of the functioning of the immune system, which contributes to the development of the predisposition to bronchopneumonia in young cattle. Keywords—cows, calves, microbronchitis, bronchopneumonia, leukocyte differential count, hormonal status