EFFECTS OF LEVEL OF COPPER SUPPLEMENT AND REMOVAL OF SUPPLEMENTAL COPPER FROM THE DIET ON THE PHYSICAL AND CHEMICAL CHARACTERISTICS OF PORCINE DEPOT FAT

Abstract

One hundred crossbred pigs were used in two experiments to study the effects of period and level of copper supplementation of swine diets on the physical and chemical characteristics of porcine depot fat. In the first experiment the presence of 250 ppm supplemental copper in the diet significantly (P < 0.01) increased the phospholipid content, decreased the melting point, increased the weight percent of unsaturated fatty acids, and decreased the weight percent of saturated fatty acids present in the backfat of pigs at 23, 46, 69, or 92 kg. Removal of supplemental copper from the diet at 23, 46, or 69 kg resulted in a backfat at 92 kg whose physical and chemical characteristics were similar to those observed in the control animals. In the second experiment all levels of supplemental copper tested significantly (P < 0.01) decreased the melting point, increased the weight percent of unsaturated fatty acids, and decreased the weight percent of saturated fatty acids in the depot fat at market weight. These changes were consistent and unrelated to level of supplemental copper in the diet: 125, 150, 175, 200, 225, or 250 ppm. The data are discussed in relation to changes in the proportions of individual fatty acids.