Abstract
Three experiments involving 116 individually-fed pigs were conducted to determine the interactive effects of environmental temperature (10, 22.5 or 35 C) and dietary fat supplementation (0 or 5% bleachable, fancy tallow) on the performance and carcass characteristics of growing (24 to 64 kg) or finishing (68 to 93 kg) swine allowed to consume a .9% lysine, corn-soybean meal based diet ad libitum. Live weight gains were depressed in pigs maintained in the warm (35 C) environment. Efficiency of energy utilization responded quadratically as environmental temperatures increased, with the most efficient gains obtained at 22.5 C. Carcass length and percentage lean cuts were reduced and backfat thickness tended to be depressed in pigs maintained in the cold (10 C) environment. Dietary fat supplementation improved growth rate and efficiency of energy utilization in pigs maintained at 22.5 or 35 C, but not in those housed at 10 C. Similarly, carcass backfat thickness and percentage fat were increased in pigs fed supplemental fat in the 22.5 and 35 C environments, whereas fat supplementation depressed carcass fat content in growing pigs maintained in the 10 C environment. These results indicate that (1) the rate, efficiency and composition of growth in pigs fed ad libitum is influenced by the environmental temperatures in which they are maintained, and (2) the response of the pig to dietary fat supplementation is altered by the environmental temperature in which it is fed. Copyright © 1979. American Society of Animal Science . Copyright 1979 by American Society of Animal Science