Effect of l-arginine on spermatological characteristics and semen storability in rams

This study was conducted to determine the effect of L-arginine on some reproductive parameters and semen storability in rams. In the experiment 1, erection time, spermatological characteristics and seminal plasma arginase activities of rams were examined after injection of L-arginine at 5 mg / kg dose every other day for 7 weeks. In the experiment 2, the semen samples were subjected to short and long term storage process after in vitro addition of L-arginine at the doses of 0.1, 0.5, 1, 5 and 10 mM to samples. When compared with the control group, i.m. L-arginine injections provided significant reductions in erection time (after the 3rd week, p<0.01) and abnormal spermatozoon rate (only at the 2nd week, p<0.01), but significant increments in mass activity (p<0.01), motility (p<0.05, p<0.01), concentration (at 3rd, 5th, 6th weeks, p<0.01) and membrane integrity (after the 3rd week, p<0.05, p<0.01). When the samples stored in short term at + 4 °C were evaluated, it was observed that the addition of 10 mM L-arginine to semen samples decreased the motility after the 12nd h and membrane integrity after the 48th h (p<0.05), but the addition of 0.5 mM L-arginine increased the arginase activity at the 24th and 96th h and its 10 mM addition decreased this activity at the 24th, 72th and 96th h. The motility of frozen - thawed semen was determined to be high in group added with 0.5 mM L-arginine and to be low in 10 mM group while the membrane integrity was found significantly high in the 0.5 mM group (p<0.01). A significant reduction was observed in semen samples supplemented with 10 mM L-arginine in terms of arginase activity (p<0.01). In conclusion, i.m. application of L-arginine provides a shortening in the erection time and an increment in semen quality parameters of rams. It was concluded that the in vitro addition of 10 mM L-arginine to semen damages spermatozoon quality during both short- and long-term storage, but the addition of 0.5 mM dose to semen would be useful during storage.