[Penetrating capacity of bull spermatozoa in vitro]

Studies were carried out on the penetrating capacity of bull spermatozoa in an estrous secretion, a modification of Kremer's method being employed by the authors. The new method seemed to be more readily applicable in the practice. It was found that the penetrating capacity was highest following thawing of semen at 39 degrees C, the pH value of the secretion being 6.8-6.9. The adding of the cytochrome C enzyme to the spermatozoa at the rate of 1 mg/cm3 of such semen increased the penetrating capacity by 22 per cent. When the thawed semen was allowed to stay for fifteen minutes the penetrating capacity of spermatozoa in the estrous++ secretion dropped by 33 per cent.