Sociosexual stimuli and gonadotropin-releasing hormone/luteinizing hormone secretion in sheep and goats

Reproductive outcomes using different distances for preconditioning for the male effect in Anglo Nubian goats during two distinct climate seasons

“…More recent reports have suggested that the presence of bucks or rams does not induce refractoriness to the male effect (delGadillo et al, 2006;. The introduction of new fertile males into these herds (containing males and females) triggers physiological and behavioral phenomena similar to those observed in females previously isolated from males (delGadillo et al, 2006;véliz et al, 2006;hawken and MarTin, 2012). Despite the relevance of these findings to the understanding of the male effect on female reproductive physiology, experimental settings are not practical to commercial goat and sheep production systems.…”

“…It has been suggested that the male effect requires the complete isolation of males from females, in order to avoid visual, physical, hearing, or olfactory contact between the sexes (CheMineau, 1983(CheMineau, , 1987walkden-Brown et al, 1993;hawken and MarTin, 2012;keller and lévy, 2012). More recent reports have suggested that the presence of bucks or rams does not induce refractoriness to the male effect (delGadillo et al, 2006;.…”

“…The "male effect" is a simple strategy of reproductive management that stimulates and synchronizes estrous cycles in goats and sheep (delGadillo et al, 2006;hawken and MarTin, 2012;keller and lévy, 2012). This is an important alternative to using hormone-based protocols, which, although viable from a technical standpoint, require relatively expensive pharmacological products and conflict with the growing public demand for hormone-free livestock production (delGadillo et al, 2006).…”

“…Despite intense research on the male effect, the minimal conditions to achieve its full potential with regard to females' reproductive behavior and performance remain a matter of debate (delGadillo et al, 2006;hawken and MarTin, 2012;keller and lévy, 2012). With regard to the preconditioning period, CheMineau (1983) suggested that 21 to 28 days is sufficient, while other researchers have concluded that preconditioning requires two weeks (MarTin et al, 1986).…”

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

“…The sociosexual relationships, particularly the "male effect," can be used to stimulate the activity of the hypothalamo-pituitary-ovarian axis in goats and ewes during the seasonal anestrus [1][2][3]. 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].…”