To study the anabolic aspects of lactation in cows in connection with the intensity of ketogenesis in the new body period

Abstract

The article discusses the results of a study of the milk productivity of cows in connection with the content of beta-hydroxybutyric acid in the blood during the new calving period. The studies were carried out on highly productive full-aged cows of the second and third lactation. The animals were divided into three groups according to the content of beta-hydroxybutyrate - up to 1.0 mmol/l; from 1.0 to 2.0 mmol/l and over 2.0 mmol/l. It has been established that an increase in the content of ketones in the blood is associated with hypoglycemia. Cows with increased levels of beta-hydroxybutyric acid at the beginning of lactation showed higher daily milk yields over a five-month period of observation. In the fourth and fifth months of lactation, the milk yield of these cows was higher than in groups 1 and 2 by 14.6-15.8% and 18.5-20.1%, respectively. In addition, the total yield of fat in this group is greater than in the first and second - by 12.8% and 10.7%, protein - by 9.7% and 11.2%, and lactose - by 8.5% and 13.5%, respectively. A calculation indicator was proposed - the lactation anabolism index, which is calculated using daily milk yield, mass fraction of milk protein and urea concentration. An increase in this index indicates the activation of anabolic reactions, a decrease indicates a surge in catabolic processes. An increase in the lactation anabolism index was found in cows of the third group at 4-5 months of lactation with a significant increase of 44.8-45.8% in comparison with groups 1 and 2. A high metabolic potential for further productive lactation was established in cows that had increased concentration of beta-hydroxybutyric acid in the new calving period.