Seasons dynamics of biochemical parameters of blood of cows during the dry period

Abstract

The study of the metabolism in the body of cows, depending on the physiological state, factors of feeding and the conditions of content in different seasons of the year, is a necessary condition for the direct effect on their reproductive capacity and productivity. In particular, the scientific and practical interest is the disclosure of physiological and biochemical mechanisms, which are associated with the characteristics of metabolism in the body of cows during pregnancy. The purpose of the research was to study the features of protein metabolism in highly productive deep-calving cows in different seasons of the year. The object for the study is served cows with milk production of 5–6 thousand kg for lactation at 8–9 months of pregnancy and blood samples taken from them. Biochemical study of cows blood plasma was carried out according to generally accepted methods. The recorded seasonal changes in protein exchange of deep-calving cows (Table) were cyclic. In contrast to the total protein content, seasonal differences in its fractional composition were also detected. The dynamics of the change in protein ratio is similar to that of albumin. During the summer, the content of a-globulins increased by 20.1 %, b-globulins by 17.3 %, g-globulins per 20.5 % compared with the spring period. In dry-bodied cows, the activity of ALT and AST in winter increases, reaching its maximum value but in the summer activity of ALT significantly decreased, and its activity was even less than the physiological limits. ACT activity was the lowest in the autumn. Determined that seasonal changes in the protein metabolism of dry cows were cyclic character. A decrease in the content of globulins (due to a-, b- and g-globulins) was observed during the winter period compared to the summer period. This characterizes the high activity of protein metabolism in the summer with the decline in winter. In dry cows, the albumin content and protein ratio reached a maximum in winter with a significant decrease in spring and summer, and in the autumn they again started to rise. The degree and direction of changes in ALT and AST activity were similar to seasonal changes in albumin content. This indicates a low intensity of protein-synthesizing processes in the liver in summer.