The hormonal control of ovulation in the immature lamb

Abstract

1. Thirty-four lambs varying from 1 week old up to 22 weeks have been treated with: (a) p.m.s. alone; (b) Progesterone + p.m.s.; (c) p.m.s. + chorionic gonadotrophin (c.g.).2. At 1 week old the lamb's ovaries were unresponsive to treatment (a).3. At 4 weeks follicular growth was obtained in groups treated with both (a) and (b).4. At 8 weeks of age follicular stimulation was obtained from treatment (a), follicle luteinization from (b), and ovulation from (c).5. At 10 weeks luteinization was observed in (b) and ovulation in (c).6. At 12 weeks luteinization occurred following treatment (a) and ovulation followed treatments (b) and (c).