INFLUENCE OF LEVEL OF COPPER SUPPLEMENT AND REMOVAL OF SUPPLEMENTAL COPPER FROM THE DIET ON THE PERFORMANCE OF GROWING-FINISHING PIGS AND ACCUMULATION OF COPPER IN THE LIVER

Abstract

One hundred crossbred pigs were employed in two trials to study the effects of various periods of copper supplementation of the diet at several levels to a maximum of 250 ppm on the performance of growing-finishing pigs, and the accumulation of copper in the liver. The presence of supplemental copper in the diet for any period or at any level did not significantly improve the growth rate of pigs. When included in the diet up to 23, 46, or 69 kg liveweight there was a trend to improved growth rate; however, when included in the diet until 92 kg, growth was depressed. This depression was significant (P < 0.05) only for the 250-ppm level in experiment 2. Removal of supplemental copper from the diet at 23, 46, or 69 kg liveweight depressed growth rate to 92 kg. The presence of supplemental copper in the diet at all levels studied significantly (P < 0.01) increased liver-copper concentration. Removal of copper from the diet at 23 or 46 kg liveweight reduced liver-copper concentration measured at 92 kg liveweight to control levels; removal from the diet at 69 kg liveweight reduced liver-copper concentration at 92 kg by 50%.