Effects Of Vitamin E On Growth Performance And Antioxidant Function In Peking Ducklings

Two trials were conducted in our study. The experiments were conducted to study the effects of vitamin E on growth performance, antioxidant index of plasma and liver, and vitamin E requirement of peking ducklings. Our objective was to provide the basis for formulation of vitamin E requirement of peking ducklings.Experiment I was designed by single factor completely randomized. 7 dietary vitamin E levers (8, 13, 18, 28, 48, 108, 408 IU/kg) was conducted with Peking ducklings to estimate the vitamin E requirement of growing ducklings from 1 to 21 d of age and the effect of vitamin E on antioxidant function. A total of three hundred ninety-two 1-d-old birds were allocated to 7 dietary treatments, each consisting of 8 replicates of 7 birds. The results showed that dietary vitamin E supplementation improved peking ducklings'growth performance and the vitamin E requirement of daily weight gain was no less than 13 IU/kg during a 21-d growth period. A linear increase was observed in plasma and hepaticα-tocopherol concentration with increasing content of vitamin E in the diet, and there was a high positive relationship between plasmaα-tocopherol and hepaticα-tocopherol concentration (R2=0.9995). Serum and hepatic SOD and GSH-Px was not affected among the different treatments. A negative relationship was observed between plasma MDA concentration and plasmaα-tocopherol levels, and a positive relationship was evidenced between hepatic MDA concentration and hepaticα-tocopherol levels. Compared with the control group, dietary vitamin E (8, 13, 18, 28, 48, 108, 408 IU/kg) significantly decreasd the amount of MDA generated in the liver of 21-d-old peking ducklings. This response provided a significant fit to a linear equation {Y(hepatic MDA)= 2.092-0.0029X(dietary vitamin E), R=0.7133}. The result showed that optimal supplementation of vitamin E in diets could improve hepatic antioxidant fuction of peking ducklings.In Experiment II, 192 male white peking ducklings with 1-d-old were allotted into four treatments, each included 6 replicates and one replicate with 8 ducks. Four levels of dietary vitamin E in Experiment II were 1, 11, 21, 101 IU/kg respectively. The trial period was 21 days. The results showed that vitamin E could improve peking ducklings'performance during a 21-d growth period and the vitamin E requirement of daily weight gain was no less than 11 IU/kg. The relationships of plasma and hepaticα-tocopherol concentration and content of vitamin E in the diet, and hepatic MDA concentration and hepaticα-tocopherol levels were consistent with Experiment I.In conclusion, appropriate supplementation of vitamin E in diets could improve growth performance and hepatic antioxidant fuction of peking ducklings, and the vitamin E requirement of daily weight gain was no less than 13 IU/kg during early growth period.