EN
The goal of the study was to analyze changes in the hematological parameters of show jumping horses in aerobic training during the yearly training cycle. We also tried to evaluate the effect of these changes on sport results of the horses. Twenty-six noble horses were studied in the research. The investigation lasted from October 2008 until September 2009. That period was divided into trimesters. In each trimester of the training cycle, blood indices (RBC, HGB, HCT, MCV, MCH, MCHC, RDW) were determined, and the Success Sport Index was calculated for each horse. Analysis of variance with repeated measurements and Spearman correlation coefficients were used for data analysis. All hematological parameters were within the normal range for horses. Changes in some parameters during the yearly training cycle were statistically significant. The values of RBC and HCT were significantly higher in trimester II, and these values coincided with a higher value of the Success Sport Index. MCH and MCHC gradually decreased in consecutive trimesters of the yearly training cycle. The lowest levels of HGB, MCH and MCHC were observed in the last trimester, that is, in the summer competition period, which may suggest some disorders in hemoglobin synthesis. Changes in these parameters were more pronounced in mares and geldings than in stallions. The blood indices and their correlations can provide useful information not only about the health status of the animal, but also about erythoropoiesis and hemoglobin synthesis. Analysis of hematological parameters should be performed regularly, and training cycles should be adjusted to erythoropoiesis.