EN
The author performed investigations in order to evaluate the efficiency of mycostatine in the cultivation diagnosis of the Trichomonas foetus Ried on Schneider's medium. Preputial rinsing smears of 500 bulls originating from the a rea of Katowice Province were inoculated simultaneously on normal cultural media and on media containing a dose o 400 units/ml mykostatine. In 38 cascs (7.5 per cent) mold and in 12 cases (2.4 per cent) yeast fungi have been discovered in normal substrata, whereas media with addition of mykostatine showed mold only in 3 cases (0.6 per cent) and yeast fungi in one case (0.2 per cent). Positive results investigations aiming to discover Trichomonas foetus Ried. in the material examined proved to be fully convergent (100 per cent of conformity).