Physiological properties of platelet aggregation in Ayrshire cattle during the first year of life

Resumo

Surveys were performed with 248 healthy Ayrshire calves, including 74 newborn calves, 65 milkfed calves, and 42 vegetarian-fed calves. During the first year of life, the summation index of platelet aggregations induced by ADP, ristomicine, and collagen gradually increased, reaching 22.40 ± 2.16%, 8.23 ± 0.27%, and 8.14 ± 0.81%, respectively. The most stable aggregations were the aggregations induced by ristomicine. The index of platelet disaggregation induced by ristomicine reached the minimum values (2.21 ± 0.09) at the age of 12 months. The aggregations induced by ADP and collagen were less stable. The indices of platelet disaggregation induced by collagen and ADP tended to increase up to 2.70 ± 0.24% and 12.22 ± 0.76%, respectively. The low level of the platelet hemostatic activity, which is typical for the Ayrshire cattle during the first year of life, ensures both the adaptation of the hemostasis processes to the environmental conditions and the optimal capillary perfusion in the growing and maturing organs.