Effect of Copper on Plasma Ceruloplasmin and Antioxidant Ability in Broiler Chickens Challenged by Lipopolysaccharide

The effects of dietary copper (Cu) supplementation in broiler chickens challenged with a single injection of Salmonella typhymurium lipopolysaccharide (LPS) on the antioxidant capacity and plasma levels of ceruloplasmin (Cp) were evaluated. The broiler chickens were provided with a basal diet or diets supplemented with 8 and 50 mg/kg Cu from 1d of age. At 25d of age, 48 chickens with similar body weight were selected from each diet. Half of the chickens in each dietary treatment were injected intraperitoneally (i.p.) with LPS (1 mg/kg body weight). The other half was injected with saline, serving as the control. Body weight gain and feed consumption were significantly suppressed by LPS challenge during the first 12-h after injection, regardless of dietary Cu levels. Feed efficiency was reduced by LPS injection during the 72-h experimental period. Dietary Cu levels had no significant effect (p>0.05) on the plasma ceruloplasmin concentrations in chickens injected with saline. In contrast, high dietary level of Cu elevated plasma Cp levels in chickens with LPS challenge. Short-term LPS challenge had no significant effect on the antioxidant ability of broilers, as indicated by superoxide dismutase, ferric reducing/antioxidant power and the thiobarbituric acid reacting substances in the plasma. The result suggests that high dietary Cu level (as much as 50 mg/kg supplementation) is favorable for coping with short-term LPS challenge through upregulating plasma Cp levels.