EN
The purpose of the studies performed on 479 bulls of various breeds ageing 13—16 months was to establish a frequency of appearance of specific anti Chlamydia psittaci antibodies in sera and the effect of chlamydial infection on semen properties. Depending upon a sort of antigen used from 4 to 14% of bulls reacted positively at a titre 1:16 and 1:32. In positively reacting animals without any clinical symptoms of infection of the genital organs decreased a volume of ejaculates, percent of spermatozoons showing normal movement was lowered, concentration of spermatozoons decreased and increased the number of spermatozoons showing morphological changes.