The present work was undertaken to screen single and compoundfeed for mould and mycotoxins contamination. 155 samples of singleand compound feed (40 samples of yellow corn, 22 wheat, 6 tibn, 17NAC, Vit. C and vit. E combination treated birds of NHST and HST groups (group IV, V and VI) exhibited significantly increased activities of erythrocyte CAT, GPX and GSH levels, while MDA level showed significant decrease when compared with HST-untreated Plasma activities of SOD at 31 & 43 days and CAT at 31 days were significantly decreased, while MDA level at 21 & 31 days showed a significant increase in HST groups (II & III) when compared with group I (Table 5.a and 6.a). It was also observed that NAC,HST-untreated birds of group II and group III showed significant decrease in the activities of liver SOD, CAT and GR in addition to GSH, vit. C and vit. E concentrations while GPX activity and MDA level showed a significant increase when compared with groSimilarly, the activities of liver SOD, CAT, GPX and GR, in addition to GSH, vit. C and vit. E levels showed significant increase, while MDA level showed significant decrease which be noticed in NAC, vit. C and vit. E combination treated birds of group IVThere were significantly down regulation in pattern of expression of Mn-superoxide dismutase and catalase in both one day heat stress and two days heat stress groups. Meanwhile, the levels of gene expression of Mn- superoxide dismutase and catalase were iIt can be concluded from the present study that supplementation of antioxidants (NAC, vit. C, and vit. E) in broiler feed exerts a heat stress ameliorating effect through alteration in both enzymatic and non-enzymatic antioxidative systems of erythrocytes