ABSTRACT
The course of all the ontogenesis in cattle is closely connected with the dynamics of blood system indices which are largely integrated in the animals’ bodies. Interest to peculiarities of platelet activity in high-productive cows increases because of its great signification for the optimum of microcirculation, anabolism and maximal productivity. The aim of the research: to study peculiarities of platelet activity in healthy Ireshire heifers being on supplementary breeding. We examined 36 Ireshire heifers at the age of 12, 15 and 18 months which were on supplementary breeding. We applied hematological and statistical methods of investigation. The most active platelets’ aggregation was noted in response to adenosine diphosphate being maximal to the end of observation. Collagenic and ristomicinic aggregation had less evidence and similar directivity. Summarizing index value of platelets’ aggregation with three used inductors was equal to the end of observation to 25.6±0.05%, 10.0±0.26% and 10.3±0.39%, respectively. It indirectly pointed at high integrity of vessels’ endothelium in the animals and little concentration of von Willebrand’s Factor in their plasma. Disaggregative platelets’ activity in respect of all the applied inductors had an upward trend in the observed heifers counterbalancing the rise of aggregation. Detected low platelets’ activity in Ireshire heifers should be considered as the necessary condition for optimal provision of anabolic processes in their growing tissues and of the basis for their future high productivity. Received results can be used in future researches of Ireshire heifers as normative values.