Effect of l-arginine addition on long-term storability of ram semen.

This study was conducted to investigate the effect of l-arginine addition on long-term storability of ram semen. Six Akkaraman rams were used as material. Semen samples were collected. Pooled samples were diluted and were divided into six equal aliquots. While aliquot 1 was kept as control, the stock solutions including 0.1, 0.5, 1, 5 and 10 mm l-arginine were added to other aliquots. All aliquots were routinely frozen in 0.25-ml straws at -130°C liquid nitrogen vapour and stored in liquid nitrogen -196°C until being analysed. The equilibrated and thawed sperm motility, membrane integrity and arginase activity were evaluated. While the 10 mm l-arginine supplementation significantly (p < .001) decreased equilibrated sperm motility, the 5 mm significantly (p < .05) increased the membrane integrity and arginase activity in comparison with the control group. The motility (p < .001) and membrane integrity (p < .01) were determined to be highest in 0.5 mm group, while significant reductions were observed in motility (p < .001) of 10 mm group and arginase activity (p < .05) of 1, 10 mm groups as compared to the control group. It was concluded that in vitro addition of 0.5 mm l-arginine to ram semen may be useful, but 10 mm may be harmful to spermatozoa quality during long-term storage.