COMPROMISED ANTIOXIDANT STATUS ASSOCIATED WITH ASCITES IN BROILERS

Tissue infiltration by white blood cells in poultry with ascites has been reported, which could alter endogenous antioxidant status from oxidant stress. Therefore, the objective of this study was to determine the effect of ascites on ascorbic acid, tocopherol, and glutathione (GSH), which are major intracellular antioxidants. Broiler chicks (1 day) were placed in environmental chambers maintained with normal ventilation (Control) or under low ventilation, which produced a cumulative mortality of 31.3% due to ascites. At 3,5, and 7 wk, lung and liver tissues were obtained from control birds (n = 5) and from birds in the low ventilation chamber with (ASC, n = 5) or without (NASC, n = 5) overt symptoms of ascites. There were no differences in tissue ascorbate, tocopherol, and GSH between the control and NASC groups with the exception of hepatic tocopherol at 7 wk, which was higher (P < .05) in NASC birds than in ASC and control birds. In general, lung and liver concentrations of all three antioxidants were lower (P < .05) in ASC birds than in NASC and control groups. Uric acid, a product of purine metabolism, was lower (P < .05) in liver and lung in ASC birds at 3 wk compared with control birds. However, uric acid concentrations in ASC birds were higher (P < .05) in the lung and serum at 5 wk, and in the liver at 7 wk compared with NASC and control birds. Although the lower levels of antioxidants in ascitic birds may be due in part to decreased feed intake, the results indicate that antioxidant, status is compromised during ascites produced by this low ventilation model and could be important in the development of ascites in poultry.