EN
Clinical examinations of the reproductive tract at the day of oestrus (0) were performed in 159 cows aging from 2 to 11 years. In the part of animals clinical examinations of ovaries at the day 1 to control ovulation were also included. At the day of oestrus in 87% of cows the ovarial follicle was palpable or ovaries were smooth, in 7.6% of cows the luteal corpuscle was present and in 5% of animals ovarial cysts were diagnosed. Moreover, in 6 cows were formed ovarial cysts diagnosed in 5 cases earlier as follicle which then transformed to cysts. Out of 47 cows with diagnosed follicles at day 0 in 13 (27.7%) follicles were present also at the day 1 pointing to a delayed ovulation in relation to the insemination time. The results of clinical examinations and the concentration of plasma progesterone reveal a good agreement (mean 94%). The lower percentage of agreement (50%) was noted when the luteal corpuscle were diagnosed at the day of announced oestrus, probably due to palpation of secretory inactive follicles. It was found a great usefulness of clinical examinations at the day 0 and 1 for diagnosis of sterility and a good agreement between the results of clinical examinations with the determination of the plasma level of progesterone.