A mathematical representation of the ovulatory cycle of the domestic hen.

The ovulatory cycle of the domestic hen (Gallus domesticus) was postulated to be the result of the interaction of two independent systems. A circadian system ws postulated to control the restriction of ovulation to an 8-h period of the day under conventional 14 h light: 10 h dark regimes. The final phase of follicular maturation was postulated to commence after ovulation of the preceding ovum in the hierarchy. Ovulation was postulated to occur when a mature follicle was present in the ovary during the appropriate phase of the circadian-linked system. The predicted times of oviposition were within the standard error of the observed times of oviposition under 21-, 24- and 28-h photoschedules. It was concluded that this hypothesis for the control of the ovulatory cycle of the hen is consistent with current knowledge.