The purpose of this study was: - To investigate jumping sport horses health conditions influence on sport skills; - To investigate blood parameters in Lithuanian jumping sport horses before and after an active training period. Eight healthy horses ranging in age from 6 to 8 with a mean body weight o 607 +/- 86,9 kg were used in experiment. Blood samples were collected from well trained Lithuanian sport horses and tested before and after an intensive period of competition of 2006. Biochemical and morphological blood results were performed to determinate the glucose, triglycerides, cholesterol, red blood cells, haemoglobin, white blood cells, total protein, albumin value, total oxygen consumption and specific oxygen consumption before and after active summer training season. Furthermore, was analyzed mineral substances content of: calcium, potassium, phosphorous, sodium, magnesium and iron in blood serum of jumping sport horses. Physical readiness of horses according changes of haematological parameters before and after active summer competition season were in range of physiological norm. Conclusion: 1. AB ŽŽ/VšĮ “Suvalkijos žirgai” stud farm horses (weight average 544 kg) reached best sport skills in 2006 jumping contest. 2. Fodder supplements during contest season increased sport skills 37, 5%. 3. Red blood cells, haemoglobin, blood oxygen content ware considerable higher in jumping horse’s blood after intensive sport contest season in comparison with pre-contest season. 4... [to full text]