Trehalose improves semen antioxidant enzymes activity, post-thaw quality, and fertility in Nili Ravi buffaloes (Bubalus bubalis)

Our objectives were to study the effect of trehalose in extender on (1) antioxidant enzymes profile during cryopreservation (after dilution, before freezing, and after thawing), (2) in vitro quality (after thawing), and (3) in vivo fertility of Nili Ravi buffalo (Bubalus bubalis) bull spermatozoa. Semen samples (n = 20) from four buffalo bulls were diluted in Tris-citric acid–based extender having different concentrations of trehalose (0.0, 15, 30, 45, and 60 mM) and frozen in French straws. At post dilution, profile of sperm catalase (U/mL) was higher (P < 0.05) in extenders containing 15, 30, and 45 mM of trehalose as compared to control. Although profiles of superoxide dismutase (U/mL) and total glutathione (μM) were higher (P < 0.05) in extenders containing 15 and 30 mM of trehalose as compared to control. At prefreezing, sperm catalase, superoxide dismutase, and total glutathione profiles were higher (P < 0.05) in all the treatment groups as compared to control. At post thawing, the profiles of catalase and total glutathione were higher (P < 0.05) in extender containing 30-mM trehalose as compared to other treatment groups and control. Whereas, profile of superoxide dismutase was higher (P < 0.05) in extenders containing 30, 45, and 60 mM of trehalose as compared to control and 15mM group. Post thaw total sperm motility (%) was higher (P < 0.05) in extender containing 30-mM trehalose as compared to control and 15 and 60-mM groups. Although sperm progressive motility (%), rapid velocity (%), average path velocity (μm/s), straight line velocity (μm/s), curvilinear velocity (μm/s), plasma membrane (structural and functional, %), acrosome (%), and DNA (%) integrity were higher (P < 0.05) in extender containing 30 mM trehalose as compared to other treatment groups and control. The fertility rates (61% vs. 43%) were higher (P < 0.05) in buffaloes inseminated with semen doses cryopreserved in extender containing 30 mM of trehalose than the control. It is concluded that addition of 30-mM trehalose in extender improves the semen antioxidant enzymes activity, post thaw quality, and fertility in Nili Ravi buffaloes.