MALE OFFSPRING DISTRIBUTIONS IN CALVING AND FARROWING DATA

Evidence that the ratio of male to female producing sperm differed significantly from 1:1, between ejaculates of a bull, was presented in the 1996 Louisiana Dairy Report. This finding was based on DNA testing for the percentage of sperm in a sample that contained the Y chromosome. Obvious advantages could result from such natural variation in this “sperm sex ratio”, but only if corresponding differences are reflected in the sex ratio of calves produced. This report contains results of efforts to determine if such a relationship exists.