Effect of Extenders and Temperatures on Sperm Viability and Fertilizing Capacity of Harbin White Boar Semen during Long-term Liquid Storage

Abstract

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 20C within 5 days of storage, but the quality of semen stored at 15C decreased thereafter as compared to semen stored at 20C. Semen stored at 5C demonstrated rapid loss of motility already within 24 h. Both fertilization and cleavage of semen stored at 20C 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 20C was more suitable than 15C for boar semen storage, and in vitro fertilizing capacity of spermatozoa was maintained for at least 8 days in ZO+PVA at 20C. (