Beneficial Effects of N‐Acetyl Cysteine in the Different Equilibration Times on Post‐Thawed Rooster Sperm Quality

Cryopreservation is the best method for preserving rooster sperm, especially in declining indigenous breeds. Cryopreserved semen is significantly compromised due to equilibration time, cold shock and oxidative stress encountered during the freezing-thawing process. To improve the quality and fertility of thawed semen, it is essential to protect sperm cells from peroxidative damage. This study assessed the effects of N-acetyl cysteine (NAC), an antioxidant supplement, on the functional parameters of thawed rooster sperm after pre-freezing equilibration periods of 2 and 4 h. Samples were collected from 10 male Ross 308 broiler breeders and diluted with Beltsville extenders containing different concentrations of NAC (0, 0.1, 1 and 10 mM/mL) during equilibrium periods of 2 and 4 h before freezing. Our findings showed that NAC-0.1 and NAC-1 groups in 2 h increased significantly total and progressive motility (59.85 ± 3.73, 59.67 ± 3.73, 42.85 ± 2.64 and 42.80 ± 2.64, respectively), viability, and plasma membrane functionality (62.45 ± 3.51, 62.36 ± 3.51, 56.81 ± 3.51 and 56.82 ± 3.56, respectively) compared to the control groups. Furthermore, NAC-0.1-2 h and NAC-1-2 h demonstrated the lowest levels of apoptosis and intracellular reactive oxygen species (ROS), as well as the highest mitochondrial membrane potential in comparison to the control groups. These findings indicate that NAC-0.1 and NAC-1 are effective in maintaining the quality of thawed rooster sperm during a 2-h equilibration period.