EN
The level of glucose, total cholesterol and its HDL fraction, triglycerides, and free fatty acids were determined 4 weeks before delivery and 2 weeks postpartum in 45 cows. The estimation of ovary function was performed by measurements of progesterone in blood sampled every 3 or 4 days during a 60-day postpartum period. A positive correlation was found between disturbances in lipid metabolism and disorders in the fertility of cows. Moreover, an unfavourable effect of lipolysis on postpartum progesterone secretion was noted.