Summary The effect of subcutaneous injections of vitamin C on the seminal characteristics of Markhoz bucks (2–4- year-old) was studied. The bucks, trained to serve an artificial vagina, were randomly allotted into three equal groups (n = 4) and received daily either zero (1 mL normal saline; control group), or 20 (VitC20 group) or 40 (VitC40 group) mg per kg body weight vitamin C from July 06, 2006 to Oct. 06, 2006. Blood samples were taken from the jugular vein at monthly inter, als, and semen samples were collected at 15-day intervals. Testicular dimensions in the scrotum (circumference, width, and length) were also determined on the day before semen collection. The ejaculates were evaluated for volume, sperm concentration, pH, motility, and abnormal and live sperm. Testicular measurements were not affected by administration of vitamin C. The interaction between vitamin C and the sampling time was significant (P<0.05) for the concentration of vitamin C in the blood plasma and seminal fluid, sperm motility, sperm viability, sperm abnormality, and the number of live-normal sperm in the ejaculate. Vitamin C increased the levels of vitamin C in blood and seminal plasma. Both doses of vitamin C increased the percentage of progressively motile sperm showing forward motility. VitC40 injection for 90 days increased sperm motility and the effect was still evident up to 30 days after the cessation of injections. The percentage of live sperm and mass motility showed similar trends. Both doses were equally effective in decreasing the percentage of abnormal sperm. The total number of live and normal sperm in the ejaculate increased by vitamin C injections and the effect was still evident after the injections had been discontinued. The present data indicates the importance of vitamin C in the reproduction of male goats, as also shown for several mammalian species. They further show that under certain conditions, the in vivo synthesis of this vitamin in ruminants might not be su
