A comparison of electro-ejaculation with the artificial vagina for ram semen collection

Nine fertile three-year-old Romney rams were ejaculated both by means of electro-ejaculation and by the artificial vagina. The ram repeatabilities of semen volume, concentration, total sperm number, percentage normal sperm and wave motion score of ejaculates collected by electro-ejaculation were 0.17, 0.08, 0.12, 0.61 and 0.23 respectively compared with the repeatabilities of ejaculates collected by the artificial vagina of 0.28,0.79, 0.56,0.72 and 0.54. The repeatability results showed that it was possible to rank rams on the quantity of sperm produced in a single ejaculate obtained by an artificial vagina, but not on the quantity obtained by electro-ejaculation. The correlation co-efficients between the ram means for the two techniques were for volume 0.05, concentration 0.06, total sperm number -0.21, percentage normal sperm 0.73, and wave motion score 0.35. Only the percentage normal sperm coefficient was significant.