| Abstrakt: |
The severity of platelet activation in different types of productive animals affects the course of microcirculation and the level of trophism in organs, which strongly determines the growth processes. Therefore, the state of the functional properties of platelets in calves in the second phase of early ontogenesis, belonging to different breeds, is of great interest. The purpose of the work is to find out the features of platelet activity in dairy calves of the Kholmogory breed. The work was performed on 42 healthy calves of the Kholmogory breed, obtained from completely healthy cows after 2 or 3 pregnancies. The calves were examined five times during the course of the work. Biochemical, hematological and statistical research methods were used. In young animals of the Kholmogory breed during the observation, an increase in the activity of platelet aggregation in response to all tested inductors was revealed. In these animals, the number of inactive platelets decreased somewhat during the observation period. At the same time, the number of active platelets in their blood increased by 18.1% and the number of platelet aggregates of different sizes increased. These changes were based in the examined calves on increased generation of thromboxane in their platelets due to an increase in the activity of cyclooxygenase and thromboxane synthetase in them. An important role in the increase in the level of platelet activity in the observed calves was played by the increase in the amount of adenosine phosphates in platelet granules and the activation of their secretion. In addition, the amounts of actin protein and myosin protein in inactive platelets of young animals of this breed increased by 20.6% and 24.8%, respectively, during the observation period. Their concentrations in animal platelets during their aggregation also increased by 18.4% and 22.0%, respectively. As a result of the study, it became clear that for the young of the Kholmogory breed during the phase of milk nutrition, some increase in the activity of platelet functions is characteristic. This process minimizes the risk of bleeding in these calves and creates conditions for optimal microcirculation processes. The growth of intravascular platelet aggregation in dairy calves of this breed creates conditions for normal metabolic processes throughout the body during the second phase of early ontogenesis. [ABSTRACT FROM AUTHOR] |
