Serum Lh in Ewes Following Sequential Removal of Ovarian Follicles, Corpora Lutea and Stroma

The ovary exerts a dominant influence on the secretion of gonadotrophins from the pituitary gland (Nalbandov, 1964). Ovariectomy of ewes caused an increase in serum LH and FSH (Arendarčik & Maraček, 1968; Roche, Foster, Karsch & Dziuk, 1970). The purpose of this experiment was to determine which compartments of the ovary (follicles, CL or stroma) normally maintain the basal level of LH in serum during the luteal phase of the oestrous cycle and throughout anoestrus (Roche, Foster, Karsch, Cook & Dziuk, 1970; Denamur, 1972). Twenty Grade Columbia ewes of 4 to 8 years of age were penned outdoors with `painted' vasectomized rams. Ewes were checked twice daily for marks and the day of oestrus was designated Day 0 of the oestrous cycle. The ovaries were exposed at