Hypothalamic-Pituitary Function in Normal Ewes and Ewes which Grazed Oestrogenic Subterranean Clover for Several Years

Abstract

Plasma luteinizing hormone (LH) concentrations were measured in normal Merino ewes and in Merino ewes with lowered fertility which had resulted from prolonged grazing of Trifolium subterraneum L. cv. Dinninup. During the anoestrous season, LH was measured at frequent intervals before and following administration of oestradiol-17 P or gonadotrophin releasing hormone (GnRH), and around the time of spontaneous oestrus.