Dose-Dependent Effect of Green Tea (Camellia sinensis) Extract in the Post-Thawed Fertility Indicators of frozen Bovine Semen Extender

This study describes antioxidative activity of green tea (GT) extract on standard post-thawed quality indicators of frozen buffalo bull's spermatozoa. Semen samples were obtained from the bulls for three weeks through artificial vagina. Egg yolk was used as an extender, in which different concentrations of GT extract (0.0%, 0.50%, 1.0%, 1.5%, 2.0% and 2.5%) were added. Semen quality indicators studied were the percentage of motility, survivability, plasma membrane integrity and acrosome integrity of frozen buffalo bull sperms. The antioxidative effect of GT was observed at the comparatively lower concentration (0.1-1.5%) on the post-thawed quality indicators. On the other hand, the hight GT concentration (1.5%) significantly decreased the quality indicators of spermatozoa. Green tea extract enhanced the spermatozoa survivability, integrity of acrosome and plasma membrane of spermatozoa following freezing and thawing. It is suggested that the addition of 1.5% green tea extract (4 g in 200 ml methanol) can be safely used for enhanced effectiveness of fertility after thawing.