Relationship between throat feather-color pattern and photodependency of testicular function in the athens randombred control line of Japanese quail.

The relationship between throat feather-color and testicular regression and recrudescence under short photoperiods of 6 hr light (L):18 h dark (D) was examined in the Athens randombred control line of Japanese quail. In contrast to earlier studies, no differences were found in testicular regression when quail with brick red, mixed red and white, central red surrounded by white, or all white throat feathers were shifted from a photoperiod of 16L:8D to one of 6L:18D. The cloacal protuberance areas (CPA) of all groups ranged between 1.81 +/- .09 and 1.90 +/- .19 cm2 while birds were housed on the long photoperiod. Cloacal protuberance areas of all groups were markedly reduced after 3 wk of exposure to 6L:18D. Testes weights of all groups ranged between 46.7 and 54.8 mg after 3 wk of exposure to the short photoperiod. In a second experiment, cloacal foam gland development of males of the four throat feather patterns was examined during 26 wk after changing the photoperiod from 16L:8D to 6L:18D. Foam glands of all groups regressed within 3 wk of exposure to 6L:18D. Glands of birds with brick red throats or mixed red and white feathers recrudesced by 11 wk under the short photoperiod. Foam glands of birds with white throats or a band of white surrounding a patch of red did not show recrudescence at 11 or 14 wk but did so by 26 wk.