Two experiments were conducted to determine modifications in eating be
havior of heat-stressed pigs using gilts and barrows. Heat-stressed pi
gs were maintained at environmental temperatures that caused voluntary
13% and 26% reductions in daily feed consumption compared to control
temperature pigs of the same weight. For control temperature pigs, the
re was a 50% reduction in number of meals and a threefold increase in
meal size as animals grew from 40 to 100 kg. The number of daily meals
and rare of eating (g/min) for heal-stressed pigs were remarkably sim
ilar to control pigs of the same age. However for heat-stress treatmen
ts, the duration of meals was substantially reduced which apparently w
as the primary method of behaviorally adjusting to heat stress. Neat s
tress reduced liver, heart, stomach, and large intestine weights, and
tended to reduce backfat thickness indicating that pigs under hear str
ess had reduced maintenance requirements. Heat stress did not affect f
eed conversion, but substantially reduced rare of gain.