Effects of dietary organic zinc and α-tocopheryl acetate supplements on growth performance, meat quality, tissues minerals, and α-tocopherol deposition in broiler chickens
The aim of this study was to evaluate the effects of different dietary levels of zinc (Zn) and α-tocopheryl acetate (α-TOA) on broilers performance, meat quality, Zn, selenium (Se), and α-tocopherol (α-TO) tissue depositions. A total of 1,080 one-day-old Ross 308 broiler chickens (mixed-sex) were allocated to nine dietary treatments. Three levels of supplemental Zn (0, 60, and 120 mg/kg of diet) and three levels of α-TOA (0, 150, and 300 mg/kg of diet) were combined as a completely randomized design with 3 × 3 factorial arrangement. Chicks were penned in groups of 20 with six pens per treatment. The ADFI, ADG, feed conversion ratio (FCR), mortality rate, and European production efficiency factor (EPEF) were not affected by dietary treatments. In addition, supplementation of Zn and α-TOA and their interaction did not affect carcass parts yield. Drip loss of the breast and thigh muscles were significantly reduced 1.27 and 1.47% by α-tocopheryl acetate (α-TOA) supplementation, respectively (P < 0.01). Deposition of Zn in liver, breast, and thigh muscles were linearly increased by dietary Zn supplementation. Furthermore, supplementation of Zn increased Se content in the breast and thigh muscles and liver. Supplementation of either α-TOA or Zn increased deposition of α-TO in liver and the muscles. The Thiobarbituric acid reactive substances (TBARS) values in the breast and thigh muscles and the liver were diminished by supplementation of α-TOA (P = 0.0001) and there was positive interaction between Zn and α-TOA (P < 0.01), in which within each increase in Zn supplementation level, α-TOA supplementation resulted in a reduction of TBARS values. In conclusion, 300 mg/kg dietary supplementation of α-TOA could improve drip loss, nutritional content, and oxidation stability of muscle without any adverse effect on growth performance of chickens. In addition, 120 mg/kg dietary supplementation of Zn could fortify α-TOA effect to improve oxidation stability of the breast and thigh muscles as well as it resulted to higher muscles Zn enrichment.