INFLUENCE OF CORTISOL ON THE LEUKOCYTE COMPOSITION OF THE BLOOD OF ANIMALS DURING PREGNANCY

Abstract

The ability of the steroid hormone cortisol to control the leukocyte composition of blood in the body of pregnant Holstein heifers/heifers was assessed. The object of the study were pregnant and non-pregnant heifers (n=10), selected in the experimental group according to the principle of approximate analogues. They took blood at the end of the I-, II-, III-th trimesters of pregnancy. It was established that during the development of pregnancy in the blood of animals there is an increase in the total number of leukocytes by 1.27 times (P<0.05), neutrophils and monocytes in absolute and relative terms - 1.87 and 1.46; 1.93 and 1.53 times, respectively, a decrease in the absolute and relative number of eosinophils by 33.33 and 54.55%, relative - of lymphocytes (by 22.37%). The concentration of cortisol in the blood of Holstein heifers during pregnancy, compared with non-pregnant animals, decreases by 1.73 times, and then during the progression of pregnancy due to the development of the fetus, its level increases by 17.64-17.89%, compared with the first trimester of pregnancy. However, it is less than in the blood of non-pregnant heifers. In a two-way ANOVA model, the leukocyte composition of blood depends both on the trimester of pregnancy of animals, the concentration of cortisol in the blood, and the interactions of signs in the pairs "Pregnancy trimester x Leukocytes" and "Cortisol x Leukocytes"