The experimental birds remained in apparent
good health. Mortality (Table I) seemed
dependent on feeding time. A total of21 mortality
cases was recorded during the experimental
period; 10 were from chickens which had 24-h
access to feed (Treatment I), nine from those
wh ich had access to feed only at daytime
(Treatment 2), and only two in birds which had
access to feed only at night (Treatment 3).
Apparently. feed withdrawal at daytime (Treatment
3) might have lowered the birds' body temperature
and increased their ability to survive heat stress
during the hot afternoon periods.