This study investigates, in red-legged partridge (Alectoris rufa), the effects of the time to change from incubation to hatching temperature on egg weight loss, hatchability, chick weight at hatch, incubation length, and development stage at embryonic mortality. Five batches of 80 eggs each were incubated at 37.8°C during the first 18, 19, 20, 21 or 22 d of incubation, and subsequently at 37.5°...