RESUMO
BACKGROUND AND AIM: Newcastle disease (ND) is widely recognized as an extremely harmful and contagious disease of birds. Therefore, the present study aims to evaluate the effect of oxidative stress induced by the virulent ND virus (NDV) (KUDU 113) on the plasma, brain, bursa of Fabricius, NDV antibody response, and hematology as well as the ameliorative effect of the individual or combined use of Vitamins E and C on the clinical signs of NDV-infected chickens. MATERIALS AND METHODS: In this study, a total of 150 broiler chickens were included and divided into five groups: Group 1, nonsupplemented and unchallenged chickens (UCC); Group 2, nonsupplemented and challenged chickens (ICC); Group 3, Vitamin C-supplemented + challenged chickens; Group 4, Vitamin E-supplemented + challenged chickens; and Group 5, Vitamins E and C-supplemented + challenged chickens. Groups 3, 4, and 5 were supplemented with Vitamins E and C (33 and 400 mg/kg/day, respectively). Virus challenge was done with 0.1 ml of KUDU 113 7 days after the start of vitamin inclusion in their diet. Concentrations of glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and catalase (CAT) were analyzed in the plasma, brain, and bursa on days 0, 3, and 7 post-infection (pi) using the biochemical method. The blood samples were randomly collected from five chickens in each group for antibody response and hematological analyses on day 0 previtamin treatment and at 0, 3, 7, 10, 14, and 21 days pi (dpi). RESULTS: A significant increase in the concentrations of MDA and NO in the NDV-challenged chickens was observed when compared with the UCCs. Moreover, a significant decrease in GSH concentration was observed in the NDV-challenged chickens when compared with the UCCs. The activities of CAT and SOD were reduced markedly in the NDV-challenged chickens. Increases in the mean antibody titers were observed in the NDV-challenged group when compared with the UCCs from days 3 to 21 pi. The mortality rates of groups 1, 2, 3, 4, and 5 were 0%, 30%, 3.3%, 3.3%, and 26.6%, respectively. CONCLUSION: The findings of this study suggest that KUDU 113 causes oxidative stress in the brain and bursa of Fabricius of chickens. Individual supplementation with Vitamin E or C was found to be more effective in ameliorating oxidative stress, improving the immune response, and reducing mortality in KUDU 113 infections than the combined supplementation of Vitamins C and E.
