Adams N R
Aust Vet J. 1979 Oct;55(10):481-4. doi: 10.1111/j.1751-0813.1979.tb00373.x.
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.
在非雌激素性牧场上放牧的患有永久性三叶草不孕的母羊，发情发生率降低，尤其是在繁殖季节的第一阶段。这种降低是由于一些母羊不表现出发情，以及其他母羊发情活动模式更加不稳定所致。通过孕酮治疗，发情发生率恢复正常。相比之下，在雌激素性牧场上放牧的受影响母羊，发情发生率降低。
