Abstract
It is said that the bacteria contaminating semen cause a lower rate of conception than usual. Recently, Straw's method has come into use to effect the deep injection of semen. Especially in this case, bacterial contamination is worthy of attention.
The authors conducted a field survey on the state of contamination of semen and investigated the effect of antibiotics on the collection, treatment, and storage of semen in order to find any preventive measure against contamination
1) The results of the survey indicate that the semen can be protected from bacterial contamination to a large extent when the semen-collecting enclosure and the stand to be used at the time of collection are equipped with sanitary facilities and the hind quarters of a teaser cow are cleaned, when animals are prevented from irritation and uproar, and when the inner side of the prepuce of the bull is thoroughly washed.
2) The smaller the extent of bacterial contamination, the more remarkable was the effect of SP drug. When contamination was extreme, little effect was observed of SP drug.
3) The effect of SP drug was observed more conspicuously when the semen diluted with the diluent containing SP drug was stored for 4 to 6 days than immediately after the semen was diluted with the same diluent containing SP drug.
