Environmental cues and seasonal patterns of reproduction in goats

Abstract

Goats usually exhibit a seasonal sexual activity and breeding at a specific season ensures the survival of offsprings by coinciding parturition with the adequate period of nutrition and climate conditions. Photoperiod is the main modulator of this seasonality in goats within different latitudes. Other environmental cues like seasonal changes in ambient temperature cycles seem also to induce a synchronizing effect on this seasonality. Moreover, food availability was found to affect reproductive physiology. Indeed, an improved nutrition enhances sexual behavior in goats while under-nutrition and particularly a negative energy balance adversely impact this activity. On the other hand, the social interaction in this species also affects the expression of the physiology and the sexual behavior during the breeding season. Goats, generally display a good plasticity of adaptation to all weathers including hot, cold, wet and dry ones. This peculiarity seems genotype-dependent and may be crucial for an efficient anticipation of new changes in the environmental cues related to global climatic changes. In this review we outline the effect of exogenous and endogenous factors on reproduction in goats thus providing a basis for comparing previous studies on main factors controlling the breeding seasonality in this species. Keywords: Goats, seasonal breeding, photoperiod, ambient temperature, food availability, social cues, genotype.