EN
The aim of the study was to determine whether the manner of use, age and sex affect selected biochemical and antioxidant blood parameters of Malopolski horses, and whether there is an interaction between these factors. The study was conducted on 30 riding horses of the Malopolski breed divided by sex (18 mares and 12 colts) and age (2-6 years, 7-9 years and 10-16 years). The horses were also divided according to usage (recreational use and sports use). The research was conducted at the end of March and the beginning of April during two consecutive years. In each year, blood from the same horses was analysed. Blood plasma was analyzed for total protein, glucose, bilirubin, urea, uric acid, creatinine, Zn⁺², Cu⁺² and Fe⁺². In addition the activities of superoxide dismutase, catalase, plasma total antioxidant status (FRAP) and the concentration of malondialdehyde were determined. Neither the age of the horses nor their use (for recreation or sport) had significant effect on biochemical indices of blood. However, the CAT activity and the levels of MDA, zinc and iron were higher in the blood of horses used for sports than they were in the blood of horses used for recreation. Age affected the value of the biomarkers of redox status. Compared with young horses, older animals showed increased oxidative processes (an increase in MDA) and a reduced antioxidant defense (SOD, FRAP, Cu⁺², Zn⁺²). The sex of the horses had a significant influence on the levels of both biochemical and antioxidant parameters. Colts had significantly higher contents of TP, UA, SOD, CAT, Cu⁺² and Fe⁺² and lower of BIL and MDA compared to mares. The interaction observed in this study between age or sex and usage on the antioxidant parameters confirms that the redox status indicators can be helpful in assessing the welfare of Malopolski horses undergoing differentiated exertion.