LABORATORY ASSESSMENT OF SEMEN CHARACTERISTICS

The chance of a successful penetration of the oocyte and subsequent development of the zygote a gestation is depending on contributions from the maternal and paternal side as well as, in farm animals, variabels such as farm management, technician and season, etc. To study the true relation between semen characteristics and sire fertility, in other words the paternal contribution to a successful gestation, these variabels should be taken into account. Before oocyte penetration, the paternal contribution is depending on the quality of the population of spermatozoa inside the female reproductive tract; extrinsic sperm quality. Semen characteristics that might relate to extrinsic sperm quality are motility, membrane integrity, acrosome integrity, ability of binding to the zona pellucida. After oocyte penetration the paternal contribution to the developmental potential of the conceptus depends entirely on the quality of the spermatozoon which penetrated; intrinsic sperm quality. Sperm cell characteristics related to this intrinsic quality such as degree of DNA condensation are relatively new and their predictive value for probability of a successful gestation is not yet fully understood.