LAUSR

The use of frozen semen in pig industry is limited by problems with viability and fertility compared to cooled semen. Part of the decrease in motility and fertility, associated to cryopreservation, may be due to oxidative damage from excessive formation of reactive oxygen species (ROS). Frozen thawed boar spermatozoa are still considered suboptimal due to the low conception rates and smaller litters after artificial insemination. The relatively low fertility of frozen thawed boar semen is associated with many factors including cytotoxicity of the cryoprotectant, osmotic stress, injuries due to ice formation during freezing and thawing, cold shock damages and even inter and intra variations present among boars. Therefore, this study was conducted to determine the impact of conjugated linoleic acid (trans- 10, cis-12; CLA) supplementation in the cryopreservation extender frozen-thawed boar on semen quality parameters. Semen was collected from three boars (three ejaculates per boar) which were subjected to cryopreservation, without any supplementation (control) or supplemented with 50 µm CLA, and then the semen was frozen using a controlled rate freezer. Before freezing, and after thawing, the sperm motility was assessed, microscopically and viability and acrosome integrity were assessed using the flow cytometry technique. Regarding live spermatozoa, no significant differences (P > 0.05) were observed among treatments. However, statistical differences (P 0.05) were observed among treatments. In conclusion, the addition of trans-10, cis-12 isomer of conjugated linoleic acid, in the concentration used in the cryopreservation media, showed no advantages on the post-thaw boar sperm viability and integrity.