Abbasi M - Department of Animal and Poultry Nutrition, Faculty of Animal Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
Dastar B - Department of Animal and Poultry Nutrition, Faculty of Animal Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
Shams Shargh M - Department of Animal and Poultry Nutrition, Faculty of Animal Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
Afzali N - Department of Animal Science, Faculty of Agricultural Sciences and Natural Resources, University of Birjand, Iran

This study was conducted to determine the effects of various doses and particle sizes (micro or nano) of dietary zinc and zinc oxide on growth performance, serum enzyme activities, carcass characteristics, and zinc requirements in Japanese quails. A total of 576 day-old Japanese quails (both sexes) were housed in 36 deep litter floor pens. Birds received a basal corn–soybean meal diet that was deficient in zinc (27 mg zinc/kg) for 10 days post-hatching in order to deplete them from zinc reserves. Then, quails were randomly allocated to nine dietary treatments: a control treatment (27 mg of Zn/kg of diet), or one of four levels of Zn (25, 50, 75, and 100 mg/kg of diet) that were one of two ZnO particle sizes (micro or nano ZnO). Birds were fed the experimental diets from 10 to 40 days of age. Body weight and feed intake per pen were measured every 10 days and feed conversion ratio was calculated. On day 40, two males per replicate were slaughtered and carcass characteristics were measured. A quadratic increase in body weight gain (P < 0.01) and feed conversion ratio (P < 0.05) were found in zinc-supplemented quails between 20 to 30 d. Increasing dietary Zn levels significantly increased the relative weights of testes (P < 0.01), and thigh (P < 0.05). In this study, the optimal dietary Zn levels for body weight gain of Japanese quails were 90 mg/kg of diet for birds 10-20 days old, 70 mg/kg of diet for birds 20-30 days old, and 59 mg/kg of diet for birds 30-40 days old.

Zinc, Particle size, Requirement, Coturnix coturnix japonica