Features of lipid metabolism and its thyroid regulation in the body of kazakh white-headed cows breeds in the suckling period

Abstract

This article presents data on the study of the state of lipid metabolism and its correlation with the level of thyroid hormones in the body of meat-producing animals, including Kazakh white-headed cows, depending on their age and lactation period. It was found that the amount of total lipids in the blood of cows decreases with age by 22.00-24.48%, and triglycerides and cholesterol, on the contrary, increases by 13.46-16.66 and 19.17-25.41%. During lactation associated with the suckling period of rearing young animals, regardless of the age of cows, the concentration of total lipids and triglycerides decreases by 14.19-19.78% (p<0.05) and 22.22-30.76% (p<0.05), and cholesterol increases by 12.73-20.89% (p<0.05). The content of thyroxine in the blood of 5-8-year-old cows exceeds the level of first heifers by 28.13-31.84% (p<0.05), and in the middle of lactation, compared with its beginning - by 7.03 - 40.50%. The concentration of triiodothyronine at the beginning of lactation increases by 70,00% with age, and in the middle, on the contrary, decreases from 14,18% (in first-calf cows) to 4.01 times (in 8-year-old cows). The level of blood lipids is associated with the concentration of triiodothyronine, which is confirmed by the number of direct (75,00%) and reliable (30,00%) correlations. The concentration of T3 is statistically significantly correlated with the level of cholesterol (r=0.66±0.27-0.91±0.14, p≤0.05) and triglycerides (r= 0.56±0.29 - r=0.88±0.17, p≤0.05).