Out-of-season control of reproduction in subtropical goats without exogenous hormonal treatments

Some breeds of goats originating from or adapted to subtropical latitudes display seasonal variations of their annual rhythm of reproduction. The reproductive seasonality causes a seasonal production of goat-derived products affecting producers, goats’ meat and milk industry and consumers. A good knowledge of the annual rhythm of reproduction, as well as the identification of the major environmental cues controlling this rhythm in both males and females, is necessary to draw new and sustainable techniques to induce a synchronized reproductive activity outside the natural breeding season and therefore to increase the out-of-season availability of the goat-derived products. This knowledge allows to control caprine reproduction without the use of exogenous hormones, and to develop techniques adapted to the environmental, economic and social characteristics of the breeding systems. Thus, in this review we will describe how photoperiodic treatments can be used to induce the sexual activity of male goats during the period of sexual rest. Then, we will describe how these photo-stimulated males were used to induce and synchronize the sexual activity of anestrous goats maintained in intensive or extensive management conditions by means of the male effect. In subtropical latitudes, the use of the male effect performed by using photo-stimulated bucks constitutes an original and sustainable way to control goats’ reproduction.