Switching photo-stimulated males between groups of goats does not improve the reproductive response during the male effect

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

“…The patterns of the ovulatory response registered in our study coincide with those reported previously in goats exposed continuously (24 h/day) or intermittently (4, 2, or 1 h/day) to photostimulated bucks for 15 consecutive days [6,19,20,29]. In contrast, our results did not agree with those reported in ewes, in which the reduction of time of contact between both sexes decreased the percentage of ewes that ovulated: 61% of ewes ovulated when remained in contact with wethers treated with testosterone for 15 days, but these percentages decreased to 53% and 18% when females were in contact with males for 4 and 1 day, respectively [17].…”

“…In our study, males were exposed to long days followed by a natural photoperiod, a photoperiodic treatment that stimulates the endocrine and sexual activities of bucks during the nonbreeding season [11,[19][20][21]. These photostimulated males displayed intense sexual activity when in contact with females, as reported previously [5,11,21,29]. In our study, the high proportions of goats that ovulated in the control and experimental groups could be related to the use of the photostimulated males, and various studies agree with this hypothesis [5,11,20,21].…”

“…On March 15 and 21, each female was submitted to a transrectal ultrasonography using an Aloka SSD-500 scanner connected to a transrectal 7.5-MHz linear probe to determine its ovarian cyclicity [26,27]. Taking into account the duration of follicular phase in does [28], this observation, associated with the measurement of progesterone concentration in a blood sample taken immediately before introduction of males (see in the following), is efficient for the determination of the anovulatory state of these females [19,29]. There was not any doe cycling before introduction of males, which is indicative of depth of anestrus [4].…”

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

“…In this study, both inexperienced and experienced males were rendered sexually active by exposure to 2.5 months of artificial long days; as mentioned earlier, this treatment enhances sexual behaviour, odour, and vocalisations during their natural sexual resting period (March and April; Delgadillo et al 2002). Similarly, the level of sexual behaviour displayed by inexperienced males has been shown to be similar to that of sexually experienced photo-stimulated males exposed to anoestrous females through the male effect (Bedos et al 2010(Bedos et al , 2012Loya-Carrera et al 2014). However, in the present study, the occurrences of nudging showed changes between the male groups during the three days of measurement.…”

“…experienced photo-stimulated males (Fern andez et al 2011;Bedos et al 2012;Loya-Carrera et al 2014). The present results differ from those reported in sheep, since young rams with lower sexual experience induced lower proportions of ovulations than adults (61 and 78 %, respectively; Ungerfeld et al 2008).…”