Effect Of Antioxidants Combination On The Boar Sperm Quality With Cryopreservation

The increase of Reactive oxygen species (ROS) can be result as lipid peroxidation damage in the freezing-thawing process. In order to develop the frozen-thawed boar sperm quality and discuss the protection of antioxidants,Superoxide dismutase (SOD),Catalase (CAT),Melatonin (MLT),Glutathione readuced (GSH) was respectively added to boar dilution, then the changes of spermatozoa quality were estimated by detecting sperm motility,plasma membrane integrity,acrosome integrity and DNA integrity. At the same time, the optimum condition of sperm chromatin dispersion (SCD) to detect DNA integrity, of frozen-thawed boar sperm was explored; and the correlation between DNA integrity and sperm motility,plasma membrane integrity,acrosome integrity was discussed.The results revealed that SCD could be used to detect frozen-thawed boar sperm DNA integrity efficiently, and the best lysing dilution components included:Tris 0.2mol/L; Nacl 2.5mol/L; DTT 0.2mol/L; Triton X-1001%.The addition of SOD 200 U/mL,CAT 200 U/mL,MLT 0.05 mg/mL,GSH 0.5 mg/mL alone, increased post-thawed sperm motility, plasma membrane integrity,acrosome integrity and DNA integrity significantly (P<0.05). Compared with addition of SOD and CAT alone, the effect of addition of the both in combination was extremely significant on sperm motility and plasma membrane integrity (P<0.01), significant on DNA integrity (P<0.05), but nonsignificant on acrosome integrity(P>0.05); the best concentration was SOD 100 U/mL and CAT 200 U/mL. Compared with addition of MLT and GSH alone, the effect of addition of the both in combination was significant on sperm motility and acrosome integrity (P<0.05), but nonsignificant on acrosome integrity and DNA integrity (P>0.05); the best concentration was MLT 0.05 mg/mL and GSH 0.5 mg/mL. Compared addition of SOD and CAT in combination with addition of MLT and GSH in combination, the former has higher rate of plasma membrane integrity (P<0.05), the latter has higher rate of acrosome integrity (P<0.05), and nonsignificant appeared in motility and DNA integrity.Post-thawed boar sperm DNA integrity has a high correlation with motility and plasma membrane integrity (r=0.670, P<0.01; r=0.639, P<0.05); has a low correlation with acrosome integrity (r=0.468, P>0.05).Therefore, addition of combination with SOD 100 U/mL and CAT 200 U/mL or combination with 0.05mg/ml MLT and 0.5mg/ml GSH could increase frozen-thawed boar sperm quality and reduce the DNA damage efficiently. Also, SCD could be regarded as a feasible method to detect post-thawed boar sperm DNA integrity.