EFFECTS OF STEROID HORMONES ON PLATELET COMPOSITION IN THE BODY OF YOUNG ANIMALS OF THE HOLSTIN-FRIESIAN BREED

Abstract

In modern veterinary medicine, reference books with population “classical intervals” are used to decipher laboratory blood tests, but they do not reflect the biological specificity of the organism, such as sex, breed, age, and environment. Therefore, this work provides an assessment of the ability of steroid hormones (progesterone and cortisol) to regulate the platelet composition of blood in the body of young Holstein animals, as well as the determination of reference limits for hemostasis parameters. Young animals (n=10) were selected as the object of the study, selected for the experimental group on the principle of approximate analogues, from which blood was taken at 3, 6, 9, 12 and 15 months of age and hemostasis parameters were determined. It was found that the number of platelets from 3 to 15 months of age increases by 1.50 times (p≤0.05). At the same time, the concentration of progesterone and cortisol in the blood of heifers shows the least variability from the 3rd to the 9th months of rearing, increasing by 2.13 and 2.29 times, respectively. From the 3rd to the 9th month of heifer rearing, statistically significant correlations were found only in pairs with cortisol: Cortisol - Platelets (r=0.74±0.23–0.97±0.08), Cortisol - Megalotlatembocytes (r=- 0.77±0.22–-0.89±0.17). Starting from 9 months of age, progesterone significantly correlates with the number of platelets (r=0.72±0.23–0.92±0.08), thrombocrit (r=0.90±0.14–0.93±0, 13) and megalotlatelets (r=-0.90±0.15–-0.95±0.11).