HATCHING OF JAPANESE-QUAIL CHICKS (COTURNIX-COTURNIX-JAPONICA) FOLLOWING LONG, DAILY CYCLICAL INTERRUPTIONS OF THEIR INCUBATION

The adaptive advantages were studied of long, daily cyclical interruptions of incubation for the hatching of Japanese quail. The aim was to mimic in a more pronounced form the natural cyclical variations to which avian embryos may be subjected and still survive. The results indicated that by consecutive daily 8-h interruptions of incubation it was possible to lengthen the embryonic period by one-third without apparent harm and with potential improvement in hatchability. After consecutive daily 12-h interruptions of incubation the length of the embryonic period could be doubled to 33 to 34 days; however, only about one-fourth as many embryos as in the control group hatched.