Bulgarian Journal of Agricultural Science
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Functional activity of platelets in new-born calves of black-marked breed
Nadezhda V. Vorobyeva, Ilya N. Medvedev
Abstract: Hemostatic features of platelets in cattle can change depending on many factors of outdoor and internal environment. Estimation of their activity at the beginning of ontogenesis with the account of breed belonging is of great interest. The aim of the research was to determine platelets’ activity in new-born calves of black-marked breed. The research involved 32 calves of black-marked breed received from healthy cows after 2nd-3rd in-calf state. The calves were examined on the 1st-2nd, 3rd-4th, 5th-6th, 7th-8th and 9th-10th days of their lives. In our research we applied biochemical, hematological and statistical methods of investigation. In the course of the new-born phase the calves were noted to have a trend to strengthening of platelets’ aggregation to all the applied inductors. The quantity of discoid platelets in blood of calves of black-marked breed had a downward trend in the course of observation. The common quantity of activated platelets summarily increased in them by 7.1%. The quantity of circulating in blood little and also average and large platelets’ aggregates also had an upward trend in the course of new-born phase. These alterations were provided in calves of black-marked breed by an upward trend of thromboxane synthesis in platelets on behalf of strengthening of cyclo-oxygenase and thromboxane synthetase in them. Besides, it was influenced by content rise of adenosine-phosphates in platelets and a trend to strengthening of their secretion. The content of actin and myosin in inactive platelets of the examined calves increased in the course of new-born phase by 5.2% and 11.4%, respectively. At the same time, they were noted to have a trend to strengthening of actin and myosin additional formation in the course of the process of platelets’ aggregation by 6.6% and 8.7%, respectively. Received data allow considering that new-born calves of black-marked breed are characterized by low activity of platelets’ aggregation and secretion. It provides physiologically favorable conditions for microcirculation processes in them. Low intravascular platelet activity in these calves promotes the formation of necessary conditions for metabolism in their tissues and, consequently, for their fast growth and development.
Keywords: aggregation; black-and-white breed; calves; newborn; platelets; secretion
Date published: 2019-07-31
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