Reproductive response to intermittent light regimens in Coturnix coturnix japonica.

The effect of intermittent light regimens of one hour of light interspaced with dark periods of one, two or three hours, repeated three, four, five or six times per day was determined for age to first egg, hen day percent production and egg production for a 126 day experimental period in females, and the age to initial response of the cloacal gland in males. Three broad classes of response were noted based on the equivalent light period (ELP), which is defined as the interval from the beginning of the first intermittent light period to the end of the last intermittent light each 24 hour period, or the length of the single six and 14 hour light periods in the control groups. Group 1 was non-stimulated and had an ELP of less than or equal to 10 hours. There was an intermediately stimulated group with an ELP of 11 hours, and a stimulated group with an ELP of greater than or equal to 13 hours. The responses in males and females were parallel. Light intensity of either 460 lumens (average) or 2.6 lumens (average) intensity had little effect on the responses in females or males. Single, long duration exposures to light of less than or equal to 10 hours gave responses similar to intermittent regimens with ELP of less than or equal to 10 hours, while those with durations of 11 and 12 hours were intermediate and those of greater than or equal to 13 hours were equivalent to those with ELP of greater than or equal to 13 hours.