One of the major factors affecting the efficacy of response to the male effect depends on the strength of sea¬sonality of the female and male goats. In this respect, the response to the male effect varies within breeds through the seasonal anoestrous period, and among breeds from different latitude origins (Walkden-Brown et al., 1999). For example, in breeds exhibiting moderate seasonality, such as the Creole goats of Guadeloupe Island, introduc¬tion of the male may induce highly fertile ovarian activity in anovulatory goats throughout the year. In contrast, when used alone in highly seasonal breeds, the male effect can only advance the onset of the breeding season by a few weeks; it does not satisfactorily induce full sexual activity in the middle of the anoestrous period (Walkden-Brown et al., 1999).