Effects of supra-nutritional levels of vitamin E and vitamin C on growth performance and egg production traits of Japanese quails

Abstract A study was conducted to evaluate growth performance and egg production traits of Japanese quails fed diets containing different supra-nutritional levels of vitamin E and C (600, 800 and 1000？mg/kg). A completely randomised design was adopted and main effects (vitamin E and C) were arranged in a 3？×？3 factorial approach. Throughout the study (42 to 105 d), the highest feed intake (vitamin C, p？=？.01) and weight gain (vitamin E？×？C, tendency p？=？.06) were obtained with vitamin E and/or C at 800？mg/kg whereas the highest dietary efficiency with 600？mg/kg of vitamin E plus 600 or 1000 of C and with 800？mg/kg of E plus 600 or 800？mg/kg of C (vitamin E？×？C, tendency p？=？.06). The highest final body weight was achieved with 1000？mg/kg of both the vitamins (vitamin E？×？C, p？=？.02). Vitamin E and/or C at 1000？mg/kg increased egg production, weight of produced eggs (vitamin E？×？C, p？=？.04), number of produced eggs to feed ratio, weight of produced eggs to feed ratio (vitamin E and C, p？<？.01), average egg volume (vitamin E？×？C, p？=？.03), and egg shape index (vitamin E, p？<？.01; vitamin C, p？=？.01). Current findings showed that feeding vitamin E and C at supra-nutritional levels can be a good management practice in Japanese quail nutrition to promote growth performance and egg production traits under thermoneutral condition. Highlights Supra-nutritional levels of vitamin E and C can promote growth performance and egg production traits of Japanese quails. Vitamin E plus C at high doses (1000？mg/kg) can synergistically act in promoting quail growth. Dietary supplementation with vitamin E at 800 or 1000？mg/kg plus vitamin C at 1000？mg/kg can improve egg production traits