Authors : A. Orihuela
Abstract: To determine whether ewes would actively search for more than one ram to mate, 20 mature Saint Croix female sheep were induced into estrus and exposed to three adult Saint Croix rams attached by light chains to posts in each corner of a triangular field. During five days of continuous observation after progesterone withdrawal, the number of mounts and ejaculations received by each ewe and the number of rams involved was recorded. Every 15 min during the same 5 days, all ewes <10 m from the rams were listed. Thirty seven percent of the ewes were served exclusively by one ram, 43.7% by two and 18.75% received at least one ejaculation from each of the three males. After subtracting for the analysis those females that only mated once (n = 4), it was found that 16% of the ewes received two ejaculations, all from the same male, while 83% (p<0.01) received three or more serves from two or more different rams. Hence, ewes receiving more ejaculations sexually interacted with more rams (r2 = 0.72; p<0.05). All ewes observed in close proximity with the rams were mounted. Ewes displayed sexual preference for one ram (p<0.01). Eighty seven, 50.0 and 43.75% of the ewes, were served by ram A-C, respectively. It was concluded that more than 80% of the ewes receiving three or more serves, actively search for more than one ram to mate and females receiving more ejaculations, interact with more males.
A. Orihuela , 2009. Assessing Female Promiscuity from Behavioral Observation Beyond Male Influence in Saint Croix Ewes. Journal of Animal and Veterinary Advances, 8: 2708-2712.