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.