Abstract: Twenty four 12-week-old turkeys were divided into four equal groups. One of the groups was given a basal diet containing 30 mg α-tocopheryl acetate/kg feed (CONT), whereas the other groups the basal diet further supplemented with 100 mg α-tocopheryl acetate/kg (TOC), or 100 mg oregano essential oil/kg (OR), or 100 mg oregano essential oil plus 100 mg α-tocopheryl acetate/kg (ORTOC), for 4 weeks prior to slaughter. Lipid oxidation, total viable counts (TVC) and Pseudomonas spp. counts were all assessed in breast fillets stored refrigerated at 4oC for 12 days. Results showed that the OR group was more effective (P< 0.05) in delaying lipid oxidation compared to the CONT group, but inferior (P< 0.05) to TOC group which in turn was inferior (P< 0.05) to the ORTOC group. TVC and Pseudomonas spp. counts of the TOC group were not different (P< 0.05) than those of the CONT group, but higher (P< 0.05) than those of the OR and ORTOC groups, which in their turn did not differ (P>0.05) among each other.