Influence of Environmental Temperature and Dietary Fat on Backfat Composition of Swine

Abstract

Three groups of growing barrows were exposed to environmental temperatures of 0 to 5° and 25 to 30° and fed diets containing either no supplemental fat, 10% corn oil, or 10% beef tallow. Food intake was restricted on all treatments to 2 kg/pig per day. In animals fed the unsupplemented diet and to a lesser extent in those fed the tallow diet at either environmental temperature, there was a temperature gradient from outer to inner backfat layer inversely related to total fat unsaturation (iodine value). With the corn oil-supplemented diets, no clear relationship between temperature gradient of backfat layer and degree of fat unsaturation was established. Although the pigs exposed to the cold temperature exhibited greater backfat unsaturation than those exposed to the warm environment with all dietary treatments, the backfat from pigs fed the unsupplemented diet and exposed to the cold environment nevertheless decreased in total unsaturation. It was concluded that the relationship between depot fat unsaturation and environmental temperature is influenced by the intake of polyunsaturated fatty acids which are not synthesized by the pig.