RESUMO
Comparative effect of slow and rapid freezing on sperm functional attributes and oxidative stress parameters of goat spermatozoa cryopreserved with tiger nut milk (TNM) extender was examined in this study. Pooled semen samples obtained from West African Dwarf (WAD) goat bucks were diluted with Tris-based extenders containing different levels of TNM (0, 5, 10, 15 and 20 ml/100 ml extender). The diluted semen samples were subjected to slow and rapid freezing for a period of 7 days and thereafter evaluated for sperm functional attributes (percentage motility, acrosome integrity, membrane integrity, abnormality and livability) and oxidative stress (malondialdehyde [MDA] concentration and acrosin activity) parameters. Results showed that higher (p < 0.05) motility, livability, membrane and acrosome integrities in semen cryopreserved with slow freezing compared to rapid freezing. These parameters (motility, livability and membrane integrity) were higher (p < 0.05) in semen cryopreserved with 15% TNM in both slow and rapid freezing protocols. The results revealed that semen cryopreserved in slow freezing had lower (p < 0.05) abnormality compared to rapid freezing. Acrosin activity was higher in slow freezing compared to rapid freezing. Acrosin activity was higher at 15% TNM in both slow and rapid freezing. Lower (p < 0.05) MDA concentration was observed in semen cryopreserved using slow freezing compared to rapid freezing. The findings revealed improved post-thaw sperm functional attributes and oxidative stress parameters of WAD goat spermatozoa cryopreserved with 15% TNM using slow freezing.
