Previous sexual experience does not improve estrous behavior and ovulatory activity in seasonally anestrous goats in contact with photostimulated bucks

ABSTRACT

Sexually inexperienced ewes display lower estrous behavior during the first contact with rams. The objective of this study was to determine whether sexually inexperienced anestrous females display estrous behavior and ovulatory activity as the sexually experienced females, and with restricted sexual experience exposed to photo-stimulated bucks. Six bucks were rendered sexually active during the non-breeding season by exposure to artificially long days (16 h of light and 8 h of darkness per day) for 2.5 months. The first group, sexually experienced females (n = 10) had physical contact with two vasectomized bucks, and mating was allowed; the second group, with restricted sexual experience (n = 10) had contact with two vasectomized bucks through a wire-mesh fence and mating was prevented; the third group, sexually inexperienced females (n = 9) was totally isolated from bucks. At 14-month-old the females were exposed to photostimulated bucks for 15 days. The proportion of females that displayed estrous behavior, ovulations, short and normal ovulatory cycles, and pregnancy rates did not differ between sexually experienced, with restricted sexual experience, and sexually inexperienced (P > 0.05, in all variables). Similarly, the ovulation rate did not differ between the three groups of females (P > 0.05). However, the interval from introduction of the bucks to the first estrus was shorter in sexually inexperienced females (P < 0.05). Therefore, sexually inexperienced anestrous females displayed estrous behavior, ovulation, and pregnancy rate similar to those displayed by sexually experienced and with restricted sexual experience when exposed to photo-stimulated bucks through the male effect.