INFLUENCE OF SUPPLEMENTAL DIETARY COPPER ON COPPER CONCENTRATION OF PIG BLOOD, SELECTED TISSUES AND DIGESTIVE TRACT CONTENTS

Abstract

Twenty-four pigs received barley-based diets with either fishmeal or soybean meal as supplemental protein and either 0 or 250 ppm supplemental Cu. Supplemental Cu increased rate of gain for fishmeal-supplemented pigs but not for soybean meal-supplemented pigs.Cu concentration of intestinal tissue (wet basis) from the duodenum, two sections of jejunum, the ileum and colon averaged 17 ppm and of intestinal contents averaged 28 ppm when either protein supplement without Cu was fed. Addition of Cu to the diets increased concentration of Cu in both intestinal tissue (average 104 ppm) and contents (average 253 ppm), but source of protein did not influence the increase. The liver (wet basis) averaged 29 ppm Cu for unsupplemented pigs fed either protein supplement, 166 ppm for Cu-supplemented pigs fed soybean meal and 329 ppm for Cu-supplemented pigs fed fish-meal. Cu levels in portal blood plasma averaged 21 μg/100 ml and were not significantly influenced by dietary treatment, sex or weight. Cu in systemic blood plasma averaged 110 μg/100 ml. Unsaturated fatty acids were increased in the backfat of pigs receiving the fishmeal-supplemented diet with Cu.Weight at slaughter (50, 70 or 90 kg) influenced Cu concentration only in contents of the colon and in the liver. Gilts did not differ from barrows in Cu concentration in tissues or intestinal contents. The results suggest that the intestinal mucosa has a major influence on the control of systemic Cu levels.