Depressed incidence of oestrus in ewes with clover disease at the beginning of the breeding season.

The incidence of oestrus was depressed in ewes with permanent clover infertility running on non-oestrogenic pasture, particularly in the first part of the breeding season. The depression was due to the failure of some ewes to display oestrus, and to a more erratic pattern of oestrous activity in the other ewes. The incidence of oestrus was restored to normal by treatment with progesterone. In contrast, the incidence of oestrus was reduced in affected ewes grazing in oestrogenic pasture.