Effects of Dietary Supplementation of Zinc and α-Tocopheryl Acetate on Performance and Zinc Concentrations in Egg and Tissues of Japanese Quails

We investigated the effects of dietary supplementation of zinc (ZnO; 0, 40, 80, 120 and 160 mg/kg) and Vit E (α-tocopheryl acetate; 0 and 40 IU/kg) on egg production, egg quality and Zn content of egg fractions and tissues in Japanese quails. Using a 5 × 2 factorial design, a total of 960 Japanese quails (Coturnix coturnix japonica) at day 70 of age were housed in cages and randomly assigned into one of ten experimental treatments, each with four replicates of 24 birds (16 females and eight males per replicate). Egg production was greater (P < 0.05) in birds fed diets containing 160 mg/kg of zinc (Zn) than those fed basal diet (control diet), but vitamin E supplementation had no effect on egg production. Quails fed basal diet supplemented with 80 mg/kg Zn showed a significant improvement in their feed conversion ratio compared to the other birds. Birds supplemented with 80, 120 and 180 mg/kg Zn had stronger egg shells than those fed the control diet, while shell thickness was lower in birds supplemented with 0 and 40 mg/kg of Zn (P < 0.05). Enrichment of Zn in egg yolk increased when birds received diets supplemented with 80, 120 and 160 mg/kg Zn compare to control group (P < 0.05). Supplementation of diet with Zn increased serum concentration of Zn when fed to quails at 120 mg/kg (P < 0.05). Thigh muscle, thigh bone, and liver Zn concentrations increased with concentration of Zn supplementation (P < 0.05). Vitamin E supplementation had no effects on laying performance, egg shell quality, and Zn concentrations in egg fractions and tissues of Japanese quail.