Hormonal changes in the blood of cows during reproductive function stimulation

Timely correction of metabolic processes within the physiologically normal range can largely opti-mize reproductive function and increase the profit-ability of dairy cattle breeding industry. In the stud-ies the effect of ribotan biocorrectors and uterotonic of gipofizin La Veyks is determined on the hormone levels in the blood of cows, with different variants of their application in the postpartum period. The stud-ies were conducted on the red-motley cows of Hol-stein breed in winter-stall period in JSC “Pedigree farm “Razumensky” of Belgorod district in Belgorod region. The first group of cows (n = 20) was intra-muscularly injected by immunomodulator ribotan at a dose of 5.0 ml/head/day within 3 days (at 2nd - 4th day) after birth. In the first day together with ribotan uterotonics gipofizin La Veyks was intramuscularly injected, just at a dose of 5.0 ml/head. The second group of animals (n = 20) was injected in similar doses, but at 30-32 days after birth. The third group of cows (n = 20) was injected by ribotan and gipofizin La Veyks in similar doses at 60-62 days after birth. The fourth group of cows (n = 20) - con-trol group (c) - was intact animals. In each group of cows (n = 5) taking blood from the jugular vein for laboratory biochemical studies was carried out. Quantitative determination of hormones estradiol-17β, progesterone, cortisol, thyroxine in cow blood serum was performed using ELISA technique (En-zyme-linked immunosorbent assay). In the 2nd group of cows a significant decrease in the release of cortisol in the blood (by 1.6 times) was found to the 60th and 90th days. This process indicated the normalization of metabolic processes and the es-tablishment of homeostasis, as well as reducing the stress response of the body due to biocorrective effect of the peptides used at the 30th day after birth. Increased postpartum concentration of thyroxine in the blood of all groups of cows to the average values of the norm indicated an increase of oxygen absorption by cells of the body due to this hormone, normalization of function of the ad-renal cortex and gonads, which was most observed in the 1st group of animals, where ribotan and gipofizin biocorrectors were usedat on 2-4 days after birth. It was found out that the intramuscular injection of ribotan immunomodulator at a dose of 5.0 ml/head/day within 3 days (at 30-32 days after birth), together with uterotonik gipofizin La Veyks at a dose of 5.0 ml/head once contributed to 75.0 % fertilization rate of cows within 120 days after birth, which was larger of 15.3; 25.0 and 25.0 % than in the 1st, 3rd and 4th (c) groups respectively, and in-semination index and obstetric diseases amounted less than 19.1 and 20.0 % than in the 4th (c) group respectively.