Effect of Extenders and Temperatures on Sperm Viability and Fertilizing

In this study the effect of extenders and temperatures on sperm viability and fertilizing capacity of boar sperm during long-term storage was investigated. Acrosomal integrity, membrane integrity, motility and hypo-osmotic resistance were evaluated by fluorescence and light microscopy. An in vitro fertilization test was performed to assess the fertilizing capacity of stored spermatozoa. The five diluents tested were ranked according to their ability to maintain sperm functional parameters and Zorlesco (ZO) extender with BSA or with PVA instead of BSA produced the best results. Zorlesco extender substituted with PVA (ZO+PVA) was found to maintain motility both at 15 and 20°C within 5 days of storage, but the quality of semen stored at 15°C decreased thereafter as compared to semen stored at 20°C. Semen stored at 5°C demonstrated rapid loss of motility already within 24 h. Both fertilization and cleavage of semen stored at 20°C in ZO substituted with PVA instead of BSA did not change significantly until day 8 of storage. It is therefore concluded that PVA can be used to substitute for BSA and 20°C was more suitable than 15°C for boar semen storage, and in vitro fertilizing capacity of spermatozoa was maintained for at least 8 days in ZO+PVA at 20°C. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 11 : 1501-