Importance of intense male sexual behavior for inducing the preovulatory LH surge and ovulation in seasonally anovulatory female goats

Absence of previous sexual experience did not modify the response of anoestrous goats to photo-stimulated bucks in Spring

“…Therefore, this study strongly supports the importance of sexual behaviour displayed by sexually inexperienced photo-stimulated males, for inducing sexual activity in anoestrous female goats, as reported in previous studies (Delgadillo et al 2006;Mart ınez-Alfaro et al 2014). …”

“…In males, photoperiodic treatment increases the testosterone secretion, odour, and sexual behaviour during March and April, months that are considered a part of their sexual rest season (Delgadillo et al 2002;Bedos et al 2012). When sexually experienced photo-stimulated males are exposed to anoestrous goats, they can successfully induce LH secretion followed by oestrous behaviour and ovulation (Fern andez et al 2011;Mart ınez-Alfaro et al 2014). The hypothesis in the present study state that if sexually inexperienced males are photo-stimulated, they could improve their sexual behaviour and display high level of nudging, ano-genital sniffing, mounting attempts, and mounts with intromission, and induce sexual response in anoestrous female goats.…”

One day of contact with photostimulated bucks is sufficient to induce ovulation in seasonally anestrous goats

“…Interestingly, the photostimulated bucks displaying an intense sexual behavior increased and maintained high plasma concentrations of LH in goats, leading to ovulation. By contrast, sedated photostimulated males that did not display any sexual behavior, but a strong odor, as awaked bucks induced only a short-term LH activation and failed to stimulate ovulation [6][7][8]. Our results and those described previously strongly suggest that the sexual behavior displayed by the photostimulated males is an important factor determining the response of females exposed to them, and we can hypothesize that it may have participated to induce the high ovulatory response observed in our study.…”

“…Indeed, the introduction of a male into a group of anovulatory females can induce and synchronize LH secretion, ovulations, and estrous behavior in the following 5 days [3][4][5]. In goats, the response of females exposed to males involves an immediate increase of LH secretion that culminates in a preovulatory surge leading to ovulation [6][7][8]. A variable number of females show estrous behavior at the first induced ovulation 2 to 5 days after male introduction.…”

“…The different results described in ewes versus cashmere and Mexican goats can be explained by the fact that RivasMuñoz et al [14] and Bedos et al [6,19,20] used males rendered sexually active by exposure to a long-day photoperiodic treatment [11,21], whereas Signoret et al [17] and Walkden-Brown et al [18] used photoperiodic-untreated males, which were in seasonal sexual rest. In fact, the high level of sexual behavior, the intense odor, and vocalizations showed by bucks induced by long-day treatments are important cues to induce endocrine and reproductive activities in anestrous goats [7,14,22]. Considering the high proportions of goats that ovulated when exposed to sexually active bucks for a short duration, we set the hypothesis that sexually active males could be able to induce ovulations in goats when permanent daily (24 h/day) contact between sexes is less than 15 days.…”