Frozen Semen Quality of Kolbroek Boars Concerning Glutathione Concentrations

Abstract

: Glutathione (GSH) is an antioxidant that is being studied for its ability to improve cellular responses to semen preservation challenges. The research goal aimed to evaluate the impact of introducing different glutathione concentrations to boar semen freezing extender (0, 1, 5, and 10 mM) on the Kolbroek boar sperm's quality after being frozen and thawed. For two hours, the collected sperm-rich fraction was chilled at 17°C. Following the 1 h of equilibration, fraction B: control (egg yolk 20% + BTS 72% + glycerol 8%), 1 mM (egg yolk 20% + BTS 70% + glycerol 8% + GSH 2%), 5 mM (egg yolk 20% + BTS 62 + 8% glycerol + GSH 10%) and 10 mM (egg yolk 20% + BTS 52% + glycerol 8% + GSH 20%) was added into the semen samples. Following that, 0.5 mL straws with the diluted, cooled semen samples were submerged in liquid nitrogen (LN 2 ) vapor and then stored inside the LN 2 tank (-196°C). After thawing (37°C), parameters of boar sperm motility, velocity, morphology and viability, membrane permeability, and Malondialdehyde content were assessed and recorded. Using the analysis of variance, the data were examined. The results revealed a difference in total motility (%) on fresh semen as compared to post-thawed control and GSH treatments. A significant difference was revealed in sperm progressive motility (%) in fresh semen (27.07±4.5). Significant differences were recorded in live sperm morphology and viability on fresh semen (81.8±2.8%) compared to control, 1, 5, and 10 mM. In the 10 mM diluted semen (78.5±6.8), the proportion of sperm with an intact plasma membrane integrity was highest ( P <0.05), while the percentage in the 1 mM diluted semen (73.0±2.7) was lower. Malondialdehyde levels were lowest ( P <0.05) in the group receiving 5 mM treatment. In conclusion, 5 mM of GSH is the required amount to be added to the freezing extender while cryopreserving semen from Kolbroek boars.