title: Effect of photoperiod upon age and maintenance of sexual development in female Coturnix coturnix japonica.
abstract: Coturnix kept in a 14L:10D photoperiod from hatch began to lay their first eggs at a mean age of 42.8 days (range 38-55). Approximately 2/3 of Coturnix held from hatch in  photoperiods of 6L:16D light were laying at 165 days of age. Mean age at first egg was 112.7 days (range 68-162 days) in 8L:16D and 130.8 days (range 117-158 days) in 6L:18D photoperiod. Coturnix transferred from a non-stimulatory (8L:16D) photoperiod to a stimulatory one (14L:10D or 24L) begun laying in 15-20 days if less than 140 days old, and in about 5 days if greater than 140 days old, when trasferred. Birds which has spontaneously begun to lay in an 8L:16D photoperiod did not stop laying when the photoperiod was reduced to 6L:18D. Those which began laying under 14L:10D photoperiod ceased laying in about 15 days if 89 or fewer days old when switched to 8L:16D, or in about 6 days if 140 or more days old. Those switched from 14L:10D to 6L:18D ceased laying in about 13 days when 76 days old, and 7 days when 89 days old.
mesh_terms: D000367:Age Factors; D000818:Animals; D003370:Coturnix / Q000502:physiology*; D005260:Female; D008027:Light; D010058:Oviposition; D010507:Periodicity; D011784:Quail / Q000502:physiology*; D012741:Sexual Maturation