Effect of micellized natural (D-alpha-tocopherol) vs. synthetic (DL-alpha-tocopheryl acetate) vitamin E supplementation given to turkeys on oxidative status and breast meat quality characteristics

Abstract

This study evaluates the effect of vitamin E supplementation source (micellized natural vs. the synthetic form) and dosage (40, 80, or 120 mg/kg) on alpha-tocopherol concentration in plasma and muscle, antioxidant capacity, and breast meat quality in turkeys. Three hundred female turkeys were randomly selected at an average live weight 63.2 g +/- 0.5 and distributed into 7 groups. One group (control) was fed a standard diet without vitamin E supplementation and the other 6 were given mixed diets supplemented with the natural (d-alpha-tocopherol) or synthetic (dl-alpha-tocopheryl acetate) form of vitamin E in 3 dosages (40, 80, or 120 mg/kg). Following 11 wk feeding, results showed that performance parameters were not modified either by source or dosage of vitamin E supplementation to the turkeys. Plasma and muscle alpha-tocopherol at d 9 of refrigerated storage were higher when turkeys were supplemented with the natural form at higher doses. Losses in the concentration of a-tocopherol in meat between the beginning and the end of the 9 d refrigerated storage were greater in the groups supplemented with the synthetic form of vitamin E compared to those receiving the natural supplementation. The relationship between plasma a-tocopherol and the Trolox equivalent antioxidant capacity followed a different trend depending on the vitamin E source. Intramuscular fat was not significantly affected by the vitamin E source supplementation; however the slope of the linear regression equation was lower for the natural form than for the synthetic form. Turkeys given the natural form had higher C18:1n-9 but lower C15:1, C17:1, C20:5n-3, and C22:6n-3 in breast muscle. Meat samples from turkeys supplemented with natural vitamin E had higher deoxymyoglobin at d 3, 6, and 9 and lower metmyoglobin at d 9 of refrigerated storage than those receiving the synthetic form. Dietary supplementation with medium doses (80 mg/kg) micellized d-alpha-tocopherol is an interesting feeding strategy for ensuring antioxidant status and improving meat quality.