Male-dependent variability of fertilization and embryo development in two bovine in vitro fertilization systems and the effects of casein phosphopeptides (CPPs).

摘要

Two experiments were carried out to characterize variability of in vitro fertilization rate among bulls and between ejaculates within bulls, and to determine the potential of casein phosphopeptides (CPP) in minimizing between and within bull variability. In the 1st experiment, semen from 5 bulls (1-2 ejaculates per bull) was compared using BO fertilization medium. Penetration and polyspermy rates showed great variation between bulls and between ejaculates within bulls (P<0.0001), whereas no significant differences were observed in cleavage or blastocyst formation rates. Supplementation of the fertilization medium with CPP increased (P<0.05) penetration, polyspermy, cleavage and blastocyst formation rates. The 2nd experiment compared the same traits as experiment 1 using BO or TALP media. Variation among bulls was observed for penetration, polyspermy, cleavage, blastocyst formation rate, and cell allocation and distribution. Rates of penetration and polyspermy were higher (P<0.05) for BO than forTALP, whereas TALP was superior (P<0.05) for cleavage and blastocyst formation. Significant bull X fertilization system interactions were found. Effects of CPP were observed only for some bulls. Bulls and ejaculates within bulls affected total blastocystcell number and the ratio of inner cell mass to total cell number (P<0.001).