Midpiece length of bovine spermatozoa and its relationships to semen traits and fertility

With the objective of identifying predictors of fertility in bulls, the cor relation coefficients of the midpiece length of bovine spermatozoa with sem en traits and fertility were estimated. Data were obtained from semen sampl es of 50 crossbred bulls submitted to a progeny test. The midpiece length w as determined in 40 midpieces of each bull through a image analysis system (Videoplan). Besides the physical traits before and after semen freezing, t he oxygen consumption rate and the cytochemical activity index were observe d. The correlation coefficients were low and non-significant (P>0.05), indi cating that the midpiece length is not a good predictor of fertility.