Boar semen variability and its effects on IVF efficiency

In vitro fertilization (IVF) in pigs is still considered sub-optimal, due to the occurrence of polyspermy, as well as the inter- and intra-boar variability in sperm characteristics. Numerous studies have investigated the relationship between fresh and frozen-thawed semen parameters, such as motility, morphology and viability with in vitro fertility in order to develop methods of selecting boars for use in IVF. These studies have clearly shown that sperm parameters have limited value in predicting IVF efficiency. On the other hand, it has been demonstrated that the requirements of boar sperm during co-incubation with the oocytes (sperm:oocyte ratio, substances added to the fertilization medium and co-incubation time) vary among boars. Preliminary assays required for individual males will be discussed with the objective of reaching maximum efficiency of in vitro fertilization.