Copper sulfate and cupric citrate supplementation improves growth performance, nutrient utilization, antioxidant capacity and intestinal microbiota of broilers

This experiment was conducted to study the effects of copper sulfate and cupric citrate on growth performance, nutrient utilization, antioxidant capacity and intestinal microbiota of broilers. A total of 360 one-day-old Ross 308 broilers were randomly divided into 5 groups with 6 replicates in each group and 15 broilers per replicate. Broilers in the control group were fed a basal diet, and animals in other four groups were fed basal diets supplemented with 2 sources (copper sulfate and cupric citrate) and 2 levels (50 and 100 mg/kg dry matter). The experiment lasted for 42 days. The results showed that dietary cupric citrate supplementation increased the average daily gain ( P  = 0.0313). The average daily feed intake and feed gain ratio, however, were not affected by dietary copper sulfate or cupric citrate ( P  > 0.10). Additionally, dietary copper sulfate or cupric citrate supplementation increased the digestibility of crude protein ( P  = 0.0554) and energy ( P  = 0.0191). For intestinal microflora, dietary cupric citrate supplementation decreased the concentration of Lactobacillus and Escherichia coli ( P  < 0.05) in the ileal digesta or cecal digesta. In addition, dietary Cu supplementation increased the pH in duodenum ( P  = 0.0008) and jejunum ( P  = 0.0589). The activities of serum Cu-Zn superoxide dismutase ( P  = 0.0899), and ceruloplasmin ( P  = 0.0269) were increased by Cu addition. The present study demonstrated cupric citrate fed to broilers has a positive effect on growth and nutrient utilization. Our results also show that moderately high Cu in the diet increases the pH in duodenum and jejunum, and reduced the concentration of Lactobacillus and Escherichia coli in the ileal digesta or cecal digesta.