Показники Ліпідного Обміну У Корів За Різних Фізіологічних Станів Та Періодів Утримання

Abstract

The aim of this research was to study the lipid metabolism in high-yielding dairy cows during different physiological states and maintenance periods. Study was conducted on two groups of animals of Ukrainian Black-and-White dairy breed. The first group was formed in the winter stall-feeding period, the second one during the grazing period. Blood samples were taken four times: the first during dry period, the second, third and fourth were withdrawn at the beginning, on the peak and at the end of lactation period. Results showed increased lipomobilization activity after calving caused on the one hand by growing requirements in metabolites for milk synthesis and on the other hand by inadequate dietary supply with metabolic energy. Highly significant increase of the content of triacylglycerols, total and esterified cholesterol and non-esterified fatty acids in blood of dairy cows was revealed. On the peak and at the end of lactation the level of indicated substances in blood gradually decreased. Influence of the period of the animals maintenance on lipid metabolism was established. For instance, after calving and on the peak of lactation serum levels of triacylglycerols, esterifies cholesterol and non-estherified fatty acids were significantly higher in comparison with such under the same physiological states but during grazing period of maintenance.