EN
The study was performed on 20 horses of various breeds, age and physiological condition. Most of them were Polish Warmblood mares, the rest were mares, stallions and geldings of two Polish breeds: Malopolski Horse and Wielkopolski Horse. All the horses were kept in a stable, in individual boxes, on straw bedding, and with ad libitum access to water. The research covered spring, summer and winter feeding periods. The aim of the study was to determine the impact of seasons on the haematological and biochemical parameters of horse blood. Blood samples for analyses were collected from the external jugular vein in May, August and February. A statistically significant increase in leukocytes was ascertained in the spring feeding period, whereas an increase in neutrophiles as well as in MCH and MCHC levels was obtained in summer. The levels of ALAT and LDH enzymes were the highest in spring. Cholesterol and glucose were the highest in the winter feeding period, and the maximum concentration of triglycerides was obtained in spring and summer. Also in summer, increased calcium and magnesium levels were observed.