Functional status of platelet hemostasis in Yaroslav calves during the dairy and vegetable nutrition phase

The purpose of the work is to trace the dynamics of platelet activity in dairy-vegetable calves of the Yaroslavl breed. The study was performed on 42 calves of the Yaroslavl breed, which were obtained after 2-3 pregnancies from completely healthy cows. In animals, an acceleration of the onset of platelet aggregation under the influence of all applied inducers by the 45th day of life was found, which was eliminated by the end of the observation. At the same time, in the blood of animals at the age of 45 days there was a short-term increase in the number of activated platelets by 27.9 %. A short-term increase in platelet activity at the age of 45 days of life occurred largely due to a 30.3 % increase in the synthesis of thromboxane in them. Of great importance in this was a short-term increase in the level of adenosine phosphates in platelets and a peak intensification of the process of their secretion. The process of short-term increase in calves by the 45th day of life of platelet activity was also provided by an increase in the amount of actin and myosin in platelets by 35.7 and 43.0 %, with the return of their levels to the outcome by the end of the observation. In animals, in aggregating platelets, by the 45th day of life, there was an increase in the additional synthesis of actin and myosin by 35.7 and 43.0 %, respectively, which leveled off by the end of the observation.