Live Spermatozoa Relationships and Fertility of Dairy Bull Semen

Abstract

The technic of differential staining of live and dead spermatozoa was used to determine the relationship of the initial percentage of live spermatozoa in semen samples, as well as the percentage of spermatozoa in diluted semen surviving at 0[degree]C for 10 min., to other semen characters and fertility. Data on 236 samples from 19 bulls, including 81 from 14 bulls on which fertility data were based, were used. Analysis of variance of the data for the various semen characters reveals highly significant differences among the bulls in regard to these semen characters. A correlation analysis was presented on a "total," "between" and "within bull" basis, but only analysis on a "between bull" basis had coeffs. of correlation sufficiently high to have any prediction value. A multiple correlation coeff. of + 0.69 of fertility with spermatozoa concn. and the percentage of spermatozoa surviving a 0[degree]C cold shock was obtained. A partial regression equation involving these factors was presented;.