Alpha-lipoic acid improves cryopreservation of rooster semen by reducing oxidative stress

Inhibiting oxidative stress is key for ensuring sperm motility during semen cryopreservation. The aim of this study was to investigate the effect of adding alpha-lipoic acid (ALA) as an extender in rooster semen cryopreservation. Different concentrations of ALA were added to the frozen diluent of rooster semen; subsequently, computer-aided semen analysis was used to determine membrane functional integrity, acrosome integrity, antioxidant capacity (based on T-AOC, GSH-Px, SOD, CAT, and MDA contents), and mitochondrial integrity. The frozen sperm ultrastructure was observed using transmission electron microscopy. The results showed that the addition of different concentrations of ALA partially to greatly improved the quality of frozen sperm; in particular, 8 μg/mL ALA significantly improved multiple parameters of sperm quality, including sperm motility and antioxidant enzyme activity, after freeze–thaw. The results of this study provide empirical and theoretical support for effective rooster semen cryopreservation and can inform the development of new protective agents in the field of livestock reproduction.