The tail in tropical hair ewes (Ovis aries) that are in estrus is used as a proceptive signal and favors ram' copulation

Two experiments were performed to determine if the tail has a role: 1) in proceptive behavior, and 2) in facilitating copulation in hair sheep. The movements and position of the tail of estrous and non-estrous ewes in response to male courtship were compared in the first study. In the second study, the courtship of rams and mating behavior directed towards tailed or tail-docked, in estrus or diestrus ewes, were compared. Both experiments were conducted with restrained ewes during 3 min assessment periods. In Experiment 1, tail movements occurred in short episodes in response to physical contact of the male, but the rest of the time the tail of non-estrous ewes was drawn inward to the body, while in estrous ewes it simply hung naturally straight downward. Ewes in estrus had many tail moving episodes (P <0.001) with more movements per episode (P <0.001), that were of greater amplitude (P <0.001) and greater elevation in angle from the body (P <0.001) than in non-estrus ewes. In Experiment 2, ejaculation latencies with non-estrous ewes were longer than with estrous ewes (P <0.0001), and rams had more attempts to mount (P = 0.008), and more completed mounts (P = 0.0003) in non-estrous than estrous ewes. In addition, rams ejaculated more times (P <0.0001), and had a greater ejaculations/(mounts + ejaculations) ratio in estrous than non-estrous ewes (P <0.0001). More rams also had anal intromissions in docked than in intact tail-ewes (P = 0.0002). In conclusion, movements and position of the tail of estrous ewes is a primary component of the proceptive behavior that facilitates mating and serves as a physical barrier to avoid anal intromissions in hair sheep.