RESULTS OF CLINICAL, HEMATOLOGICAL AND IMMUNOLOGICAL STUDIES OF COWS IN DIFFERENT PERIODS OF LACTATION

Abstract

The article presents the states of metabolic processes in the body of cattle, ensuring the realization of the genetic potential of animals. The object of the study were Holstein cows aged 4 to 6 years. Hematological and immunological studies, indicators of cellular immunity were determined. As a result of the
conducted studies, a certain relationship between immunological indicators and the level of milk productivity was revealed. In cows with a productivity of more than 7 thousand kg of milk per lactation, the hemoglobin content is 10% higher than in cows with a productivity level of less than 5 thousand kg. With an increase in productivity, a decrease in the number of immunocompetent cells and a slowdown in phagocytosis reactions in cows were observed. In cows with milk yield for lactation of 5 thousand kg of milk, the content of immunompetent cells was at the level of average normative indicators. With an increase in productivity from 5 thousand kg, cows showed a decrease in the number of T-lymphocytes by 25.4%. The T/B lymphocyte
index is 12.6% lower, and the phagocytic activity of neutrophils is 5.4% lower compared to low-productivity animals and average normative indicators. The indicator of T-lymphocytes of group 1 is higher than the indicator of group 2 and 3 by 7.3% and 10.6%, respectively. Accordingly, there was an increase in the index of monocytes of group 1 than in groups 2 and 3. Thus, it was found that with an increase in the level of dairy productivity in cows, quantitative indicators of the immune system decrease, which indicates the development of immunodeficiency conditions in them.