[Hormonal control of male and female sexual behavior in ewes: role of interactions between progesterone and estradiol].

Ovariectomized Ewes, treated daily with 100 micrograms of oestradiol benzoate (OB) show simultaneously female and male sexual behaviour. Male sexual behaviour is never seen in intact females. When given simultaneous with OB, progesterone prevents the action of the oestrogen. When given before the start of oestrogen treatment, progesterone also inhibits the effects of OB on male sexual behaviour for several weeks. By contrast, progesterone pretreatment has both inhibitory and facilitatory effect on the induction of female sexual behaviour. At first, it delays the appearance of female behaviour but then increases the response to oestrogen. These results suggest that progesterone could be involved in the dissociation between male and female behaviour normally seen in Sheep.