Abstract:

The study was conducted to investigate the effects of iron and vitamin A on performance and serum antioxidant indice in laying hens. A 3×2 completely random experiment was designed. A total of four hundred and thirty-two Hyline Brown laying hens were randomly divided into 6 treatments. Iron supplementation levels were 0, 30, 60 mg/kg, and vitamin A supplementation levels were 4000, 8000 IU/kg. The results showed that: (1) The supplementation of dietary iron increased significantly average egg weight, activity of Cu, Zn-superoxide dismulase, glutathione peroxidase and ceruloplasmin in serum, and concentration of hydrogen peroxide and inhibiting hydroxy radical capacity in serum (P<0.05)，and increased significantly total antioxidant capacity in serum at 31-34 weeks (P<0.05). (2) The supplementation of dietary vitamin A increased significantly activity of ceruloplasmin in serum (P<0.05). (3) Interaction of iron and vitamin A affected significantly the activity of glutathione peroxidase and ceruloplasmin in serum (P<0.05). The results indicated that the supplementation of iron in diet did not improved performance of laying hens, but promoted production of free radicals, and increased activity of antioxidase.