COPPER AND ZINC SUPPLEMENTATION OF PIG DIETS CONTAINING SOYBEAN MEAL OR RAPESEED MEAL (BRASSICA CAMPESTRIS cv. SPAN)

Abstract

Forty-eight crossbred pigs, equalized as to sex, were fed isocaloric, isonitrogenous diets with protein supplements from either soybean meal (SBM), rapeseed meal (RSM) from Brassica campestris cv. Span (low erucic acid oil) seed or a combination of SBM and RSM. Diets containing each source of protein were supplemented with 10, 135 or 210 ppm copper; some of the diets supplemented with 210 ppm copper were further supplemented with 200 ppm zinc in addition to the 50 ppm zinc added to all diets. Feed intake, efficiency of feed utilization and digestion coefficients for energy and nitrogen were not significantly (P < 0.05) affected by supplemental minerals, protein source or sex. Gain was lower (P < 0.10) for pigs fed RSM compared with SBM or SBM and RSM combined. Copper concentrations in the liver and kidney increased with increase in dietary copper levels. Two hundred and fifty ppm zinc decreased (nonsignificantly) copper stores in livers and kidneys of copper-fed pigs. Muscle and fat copper levels were not influenced by dietary minerals. Oleic acid (18:1) was higher in the depot fats of pigs receiving high level copper supplements. Dietary zinc or protein did not significantly affect fatty acid composition of adipose tissue.