Seasonality influence on the immunological reactivity and hematopoiesis of thoroughbred horses in the Republic of Crimea

Thoroughbred horses have limited adaptive capabilities to climatic conditions with high ambient temperature and increased relative humidity. Physical exertion in such conditions can cause "heat disease". The aim of the work was to establish seasonality influence on hematopoiesis and indicators of neutrophils phagocytic activity in thoroughbred horses. The object of the study was 12 horses aged 6-17 years old, the research material was samples of stabilized whole blood of animals that were examined eight times during the year (two studies in each season). Blood indexes during research were studied for statistical connected group differences using the Student’s T-test (their critical values). Results and discussion. The clinical condition of the animals during the entire period of experimental studies was good, the main controlled clinical indicators were normal. Throughout the year, the horses were kept in stalls, used daily exercise for 5-6 hours. When assessing the indicators of erythropoiesis, they were found to have a slight variation - up to 9.5%. At the same time, the lowest indicators in animals were noted in autumn, then (in winter) - a gradual increase and the maximum - in spring, followed by a summer decrease. Leukopoiesis rates varied much more significantly - up to 45-68%, while most of them were also minimal in autumn. The neutrophils phagocytic activity and phagocytic number were minimal in autumn, and then gradually increased, reaching a maximum in the summer period of studies. Thoroughbred horses have a pronounced effect of the season on the indicators of immunological reactivity and hematopoiesis, the lowest indicators are recorded in autumn. High summer air temperatures, persisting for a long time, lead to a decrease in the total number of erythrocytes, leukocytes and their individual types, a decrease in the concentration of hemoglobin (p function show_eabstract() { $('#eabstract1').hide(); $('#eabstract2').show(); $('#eabstract_expand').hide(); }