THE APPLICATION OF IN-VITRO FERTILIZATION TECHNIQUES TO THE PREDICTION OF BULL FERTILITY

Standard semen characteristics, such as semen volume, spermatozoa concentration, percentage of progressively motile spermatozoa or the percentage of intact acrosomes are poorly correlated with fertility. Such measures do not specifically take into account the ability of the sperm to undergo such critical in vivo procedures as capacitation, the acrosome reaction and ferilization. The recent upsurge in interest in in vitro bovine embryo production has opened the way to some possible new approaches to bull fertility evaluation. Such approaches include the assessment of fertility in terms of ability to acrosome react or to penetrate and fertilize in vitro matured oocytes and ultimately to yield competent embryos following in vitro fertilization (IVF) and culture (IVC). The present paper gives a brief overview of work carried out using such in vitro techniques in an effort to develop a definitive laboratory test for the prediction of field fertility in cattle.