The concentration of MDA in plasma and yolk was increased (P o 0.05) in high stocking density-challenged hens. Dietary supplementation with 500 mg vitamin C/kg decreased (P o 0.05) MDA values of plasma and yolk. Similarly, dietary inclusion of CrMet decreased (P o 0.05) both plasma and yolk MDA contents compared with control hens. Supplemental CrMet was more effective in reducing plasma and yolk MDA values of high stocking density-challenged hens than those kept in normal stock- ing cage, resulting in a stocking density x Cr interaction (P o 0.06).