Frozen Semen Quality of Kolbroek Boars Concerning Glutathione Concentrations

Glutathione (GSH) is an antioxidant that is being studied for its ability to improvecellular responses to semen preservation challenges. The research goal aimed toevaluate the impact of introducing different glutathioneconcentrations to boar semen freezing extender (0, 1, 5, and 10 mM) onthe Kolbroek boar sperm's quality after being frozen and thawed. For 2 h, thecollected sperm-rich fraction was chilled at 17°C. Following the 1 h ofequilibration, 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 thediluted, cooled semen samples were submerged in liquid nitrogen (LN₂)vapor and then stored inside the LN₂ 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 adifference in total motility (%) on fresh semen as compared to post-thawedcontrol and GSH treatments. A significant difference was revealed in spermprogressive motility (%) in fresh semen (27.07±4.5). Significant differenceswere recorded in live sperm morphology and viability on fresh semen (81.8±2.8%)compared to control, 1, 5, and 10 mM. In the10 mM diluted semen (78.5±6.8), the proportion of sperm with an intact plasmamembrane integrity was highest (P<0.05), while the percentage in the1 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 therequired amount to be added to the freezing extender while cryopreserving semenfrom Kolbroek boars.