474 - Comparison Between Copper Sulfate and Dicopper Oxide on Body Weight and Copper Accumulation on Growing Pigs

There are several Cu sources in the market that have different effects on pigs. We hypothesized that supplementing therapeutic doses of Cu(I)oxide (Cu₂O) in diets for growing pigs improves body weight (BW), bone mineralization, and reduces Cu accumulation in liver than supplementing pigs with Cu sulfate (CuSO₄). Two-hundred growing pigs (initial BW: 11.5 ± 0.98 kg) were randomly allotted to 5 dietary treatments. Dietary treatments included the negative control (NC) diet without Cu supplementation, and 4 diets in which 125 or 250 mg/kg of Cu from CuSO₄ or Cu₂O were added to the NC diet. The experiment was divided into 4 phases. Pig weights were recorded on d 1 and at the end of each phase. Eight pigs per treatment were sacrificed last d of phases 1 and 4 to obtain samples of liver, spleen, and the right metacarpal. Pigs fed diets containing 250 mg/kg of Cu₂O had greater (P < 0.05) BW at the end of phases 1 and 2 than pigs fed the NC diet, and tended (P < 0.10) to have greater BW at the end of phases 3 and 4 than pigs fed the other diets. Copper accumulation in liver and spleen increased with Cu dose, but at the end of phase 1, pigs fed 250 mg/kg CuSO₄ had greater (P < 0.05) Cu concentration in liver and spleen than pigs fed 250 mg/kg Cu₂O. Pigs fed diets containing 250 mg/kg Cu₂O had greater (P < 0.05) quantities of bone ash and greater (P < 0.05) concentrations of Ca, P, and Cu in bone ash than pigs fed the NC diets or diets containing CuSO₄. Therefore, supplementing diets for growing pigs with therapeutic doses of Cu₂O improves BW and bone mineralization with less Cu accumulation in liver compared with pigs fed diets containing CuSO₄.