Effects of vaginal mucus from ewes in estrus on the sexual drive and semen characteristics of hair rams (Ovis aries)

The purpose of this study was to examine the effects of vaginal mucus from ewes in estrus on sexual drive and semen characteristics of hair rams (Ovis aries). Nine intact Saint Croix males participated in 3 experimental sessions spaced 8 days apart, based on a mask with cotton that was attached to the muzzle of each animal. Each session lasted for 1 hour, and during this time, all ejaculations from each individual ram were collected with an artificial vagina. In each session, 3 animals were exposed individually in random order to each of 3 treatments. In the control group (C), the cotton of the mask was impregnated with distilled water. In treatment 1 (T1), the cotton was impregnated with mucus from the vagina of one ewe in estrus. In treatment 2 (T2), the cotton of the mask was impregnated with mucus from an ewe in estrus as in T1 group, but after 30 minutes, a cotton impregnated with mucus from a different ewe was replaced with the original. The treatment effects were similar (P > 0.05) with respect to the reaction time (485 ± 90, 585 ± 112, and 537 ± 98 seconds), number of ejaculations/h (3.86 ± 0.71, 3.86 ± 0.74, and 3.75 ± 0.68), and sperm concentration (3.63 ± 0.67, 3.47 ± 0.86, 3.59 ± 0.65 spermatozoa × 109/mL) in the 3 groups (C, T1, and T2, respectively), whereas semen volume of the T2 group (0.90 ± 0.16 mL) was larger (P < 0.05) than those of C and T1 groups (0.73 ± 0.14 and 0.72 + 0.01 mL, respectively). In conclusion, the use of a mask with vulvovaginal mucus of 1 or 2 ewes in estrus had no effect on sperm concentration and reaction time when used for a collection period of 1-hour.