The microbiological examination of 48 ejaculates obtained by an artificial vagina revealed an average number of 178 000 germs per 1 ml of semen (1900 - 758 000). When the technique was changed, the manual method being employed, 23 ejaculates were obtained from the same boars and the microbiological examination revealed 44 200 germs per 1 ml of semen, on an average. In the second part of the trial 85 ejaculates obtained by an artificial vagina from 17 breeding boars were subject to microbiological examination. The average number of germs found in this case was 99 377 (10 000 - 400 000). When boar body was washed with water or with water and soap and rubbed with a sterile cloth, prior to each collection, the number of germs per 1 ml of semen decreased to 6071 (0 - 40 000). The reduction of the number of germs in the ejaculate of washed boars is statistically highly significant, as compared with semen collection from boars without washing. The number of fungus-bearing ejaculates decreased from the original 39.9% to 9.3%.