Maternal vitamin E supplementation affects the antioxidant capability and oxidative status of hatching chicks.

The effects of maternal vitamin E supplementation on the antioxidant status of chicks were investigated. Female breeder chicks were fed corn-soybean growing diets without supplemental vitamin E for a 17-wk developmental period. After 17 wk, the birds were randomly assigned to 5 treatments and fed corn-soybean diets supplemented with 0, 40, 80, 120, and 160 mg/kg vitamin E (all-rac-alpha-tocopherol acetate), respectively. Blood samples were collected and pullets were artificially inseminated at 35 wk of age. Eggs laid beginning on d 2 after insemination were placed in an incubator. At the time of hatching, 12 chicks from each treatment were randomly sampled and killed. Livers and brains of chicks were collected for the subsequent evaluation of antioxidant status. Plasma vitamin E concentrations increased linearly (P < 0.001; r = 0.997) with the increase in supplemental vitamin E, but those in egg yolk reached a plateau at 120 mg/kg supplemental vitamin E. The malondialdehyde (MDA) concentration, an indicator of lipid peroxidation, of chick brain decreased linearly (P < 0.01; r = -0.909) with the increase in supplemental vitamin E. Pullets given 160 mg/kg supplemental vitamin E had lower plasma MDA concentrations than those given 0 mg/kg (P < 0.05). Similar results were found for the reactive oxygen species levels, an indicator of oxidative stress, of chick brain and liver. For antioxidant enzymes, chicks of pullets given 120 mg/kg supplemental vitamin E had higher (P < 0.05) activities of liver catalase than those given 0-80 mg/kg. Chicks of pullets given 160 mg/kg supplemental vitamin E had higher (P < 0.05) activities of brain superoxide dismutase than those given 0-40 mg/kg. These results indicated that maternal supplementation with high levels of vitamin E (120-160 mg/kg) enhances antioxidant capability and depresses oxidative stress in chicks.