Hormonal control of the hen's ovulation cycle

The ovarian ascorbic acid-depletion assay has been used to determine the luteinizing hormone (LH) content of plasma at different times in the laying cycle of the hen. The existence of three peaks of LH release preceding ovulation was confirmed and no fourth peak was determined. By injection of an anti-adrenergic drug (dibenzyline) to prevent ovulation, all three releases of LH were inhibited. Preceding the missed ovulation leading to a pause in the laying cycle, no peaks of plasma LH were found. These results provide direct evidence on which theories for the hen's ovulation cycle can be assessed