Animal Science Department


Date of this Version

December 1999


Published for Proceedings, The Range Beef Cow Symposium XVI December 14, 15 and 16, 1999 - Greeley, Colorado.


Breeding soundness evaluations (BSE) are conducted to qualify bulls as potential satisfactory breeders. Guidelines for acceptable measures of scrotal circumference, sperm concentration, sperm motility, and the frequency of sperm with morphological abnormalities are compiled and published by the American Society for Theriogenology (Chenoweth et al., 1992). Unfortunately, according to statistics available from USDA, only 40% of eligible bulls are subjected to a BSE. In the real world, bulls with identical outcomes in terms of physical quality of semen will still vary in actual fertility whether used for natural mating or artificial insemination (A.I).