The Physiological Characteristics of Platelets in Calves Dairy Nutrition Holstein Breed

Abstract

The level of platelet activity in the blood affects the course of metabolic processes, which is of great biological importance, especially at the beginning of ontogenesis.  There is reason to believe that in animals of different breeds there are differences in the level of platelet activity.  The work was performed on 48 purebred calves in Holstein breed, which were obtained from completely healthy cows, after normal pregnancy.  All young animals were examined and examined on the 11th, 15th, 20th, 25th, 30th day of his life.  During the study, biochemical, hematological and statistical research methods were applied.  In animals, a decrease in platelet aggregation was noted during the phase of dairy nutrition.  In the blood of calves of the Holstein breed, discocytes increased by 2.9%.  Moreover, the total number of active platelets in them decreased by 20.0%, and the levels of platelet aggregates circulating in the blood of small and large sizes decreased during the observation period by 20.0% and 40.0%, respectively.  Apparently, this was largely due to a weakening of the synthesis of thromboxane calves in platelets, a decrease in the amount of adenosine phosphate in them and a weakening of its secretion.  During the second phase of early ontogenesis, the amount of actin and myosin in the platelets of animals also decreased, which further weakened platelet hemostasis.  In addition, their generation of actin and myosin was weakened under the conditions of induced platelet aggregation.  It is clear that Holstein calves in the phase of milk nutrition are characterized by a high functional perfection of the hemostatic properties of platelets.  This provides them with physiologically very favorable conditions for microcirculation in their tissues.  This is ensured in them by a certain weakening of the activity of mechanisms providing platelet processes of adhesion, aggregation, and secretion.  It is clear that a decrease in the intravascular activity of platelets in calves of the Holstein breed during the milk feeding phase forms the optimum of perfusion and metabolism in all their tissues, which is extremely important for the rapid growth, development and creation of the basis for the future high productivity of this breed of cattle.