400 one-day old broiler chickens (Ross 308) were
obtained from a local commercial hatchery. Chicks were
randomly distributed in two light-proof controlled rooms
each containing 10 floor pens (20 chicks per pen), androse in nearly continuous lighting [23 h light (L): 1 h dark
(D), CL]. A commercial broiler mash starter diet
containing 2900 Kcal ME/kg and 22.4% CP were fed
from 1 to 10 days of age. Feed and water were provided
ad libitum throughout the experiment. Compositions of
diets in all phases of the experiment are presented in
Table 1. Starter, grower, and finisher diets were offered
from 1-14, 14-28, and 28-42 d of age. At 10 d of age, the
intermittent lighting program (IL) consisting of 1 h L: 3 h