The relationship between semen evaluation methods and fertility in the bull.

The results are presented of two experiments in which the quality of samples of bull semen was assessed by a number of laboratory tests and then correlated with the 112-day non-return percentage obtained by the use of those samples in A.I. The results reveal the inadequacy of the laboratory tests used as methods of predicting the fertility of semen samples but show that limits may be set outside which poor semen samples could be discarded.