Sexual play and its functional significance in the domestic sheep (Ovis aries L.).

All the patterns of male sexual behavior were present from the first week of age in male and female lambs. The frequency of this sexual play increased considerably during the first month of life, and returned to a low level until early puberty. These behavioral changes could not be correlated with any hormonal changes. Rearing the lambs in the absence of adult females, in all-male groups or in physical isolation until weaning at 3 months of age, was without consequence for adult sexual behavior. However, despite the low level of sexual-like interactions during the pre and early pubertal period, i.e., between 3 and 6 months of age, the sexual segregation had a clear adverse effect on the development of the copulatory activity: the occurrence of the first copulation was delayed. However, after the first mating, the level of sexual activity was not affected by the treatment.