The present study was performed on 111 adult clinically healthy Iranian fat-tailed sheep from both sexes (28 male and 83 female). Blood concentrations of oxidative stress parameters viz. malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) were determined. The reference values for oxidative stress parameters of adult clinically healthy Iranian fat-tailed sheep were as followed: MDA 0.53-0.60 mmol/l, SOD 948.65-1011.50 U/gHb, CAT 1834.29-1915.63 U/gHb and GPX 191.67-196.52 U/gHb. There were no significant differences in oxidative stress parameters among animal of the two sexes.

Key words: Malondialdehyde, Superoxide dismutase, Catalase, Glutathione peroxidase, Reference values, Iranian fat-tailed sheep