EN
The investigation was performed on 90 multiparous cows in four farms. Animals were almost identically fed and had similar milk yield during last year (6000 kg milk). Blood samples were taken 3 times (-3, -2, -1 week) before and 2 times (+1, +3 week) after parturition. Some biochemical parameters were determined. In all farms the increase of free fatty acids level was observed after parturition. The decrease in cholesterol concentration and triglyceride level after calving were accompanied. Differences in valucs of analysed parameters (AST, FFA, glucose) in cows with correct and disturbed post partum period were observed before parturition.