Figure 1

The experimental plan. The oestrous cycles of 36 ewes were synchronised using a combination of progestagen sponges and intramuscular eCG. On day 7 of the cycle following oestrous synchronisation, sampling of jugular venous blood commenced and continued until the time of ovariectomy. The next day (day 8) intravenous infusions of either saline (n = 18) or glucose (n = 18) commenced and continued for 72 hours. Ovariectomies were carried out at two times, the first at the end of the infusion period (luteal phase groups) and the second 30 h later and following the injection of a luteolytic dose on PGF given at the end of the infusion period (follicular phase groups).