Effects of astaxanthin supplementation on the sperm quality and antioxidant capacity of ram semen during liquid storage

Abstract

The aim of this study was to evaluate the effects of astaxanthin (AST) supplementation of semen extender on the quality of ram semen during storage at 4°C for periods up to 72h. Semen samples were obtained from five Small-tail Han rams by use of artificial vagina during normal reproduction season (August to October in 2014), and diluted with glucose-egg yolk buffer supplemented with 0 (control), 0.5, 1, 2, or 4μM AST. The results showed that supplementation of the extender with 2μM and 4μM of AST increased sperm vitality and plasma membrane integrity (P<0.05), and significantly reduced malondialdehyde and reactive oxygen species levels during the 72h storage period (P<0.05). Acrosome integrity did not differ among treatments. After 72h of storage in extender, samples were analyzed with computer-assisted semen analysis. The motility of sperm in the 2μM and 4μM AST treatment groups increased significantly (P<0.05) compared to the control treatment, while curvilinear velocity, progressive velocity, and path velocity were not affected. In conclusion, the present study demonstrated that supplementing semen extender with AST can improve ram semen preservation via protecting plasma membrane integrity.