Three types of acrosomal aberrations of bull spermatozoa and their relation to fertility.

The effect of acrosomal aberrations of the spermatozoa of Finnish Ayrshire bulls on the corrected non-return rate within 60 days of the first 500 inseminations was studied. The material consisted of sperm samples examined by the artificial insemination societies. All samples had been accepted for use in artificial insemination. One Giemsa-stained slide was studied for each of the 95 bulls concerned. Samples showing distinct acrosomal defects were studied by electron microscopy. Three different types of acrosomal aberration were found. One was obviously associated with subfertility in all 6 bulls in which it was detected.