Effect of dietary copper source (inorganic vs. chelated) on immune response, mineral status, and fecal mineral excretion in nursery piglets

This experiment was conducted to determine the effect of dietary supplementation with copper sulfate and cupreous N-carbamylglutamate chelate (NCG-Cu) on the growth performance, serum biochemical profile, immune response, tissue mineral distributions, and fecal excretion of minerals in nursery piglets. Eighteen healthy nursery piglets were randomly assigned to 3 dietary treatments consisting of no copper in either form (control), 650g/t copper sulfate (650g/t Cu) or 320g/t NCG-Cu (320g/t NCG-Cu) for 35 days. Pigs fed the 320g/t NCG-Cu diet showed a significantly (P<0.05) elevated growth rate, feed conversion efficiency, IgA and IgM levels, and decreased diarrhea rate compared to those fed the 650g/t Cu diet. Fecal copper (Cu) and zinc (Zn) were increased (P<0.05) when pigs were fed the 650g/t Cu diets compared with those fed the 320g/t NCG-Cu diets. Tissue Cu has limited effects on tissue mineral distribution, except for the distribution in the spleen and liver (P<0.05). These results indicated that 320g/t NCG-Cu (chelated) was as effective as 650g/t Cu (inorganic Cu) for stimulating growth and the immune response and reducing dietary fecal Cu excretion, thus reducing environmental pollution.