Usage of Some Natural or Synthetic Compounds as Antioxidant and their Effects on Cryopreservation and Penetration of Ram Spermatozoa

The current investigation was performed for determining the impact of natural (rosemary and ginseng aqueous extracts) and synthetic (L-carnitine and vitamin E) antioxidants on ram sperm characteristics during three sessions (preservation, equilibration, and frozen-thawing) using six mature Ossimi rams. Semen collection was performed twice a week for three weeks by an artificial vagina. In different sessions, ejaculates were pooled split into five aliquots. The natural (rosemary and ginseng aqueous extracts) and synthetic (L-carnitine and vitamin E) antioxidants were supplemented 20 mg/ml of each to the first four portions G1, G2, G3, and G4, respectively. However, the fifth part (G5) served as control without any antioxidant type. The results showed that sperm characteristics, sperm recovery rate and reduced glutathione (GSH) were higher (P < 0.05), but the concentration of lipid peroxidation (LPX) and enzymatic activities (ALT, AST, ALP, and LDH) were lower (P < 0.05) in G1, G2, G3 and G4 than G5 extenders post-equilibration and thawing conditions. Furthermore, the penetration ability into ewe cervical mucus was significantly (P < 0.05) better in the extended ram semen with natural antioxidant (G1 & G2) than with synthetic antioxidant (G3 & G4). The findings of this study indicated that extenders supplemented with rosemary or ginseng extract (as a natural antioxidant) could be alleviated sperm characteristics, penetration value and reduced oxidative stress marker corresponding to L-carnitine and vitamin E (as a synthetic antioxidant) during after the cooling and freezethawing processes of ram spermatozoa.