influence of different dietary levels of energy and protein on reproductive and post hatch growth performance in japanese quails

The response of laying japanese quails to dietary levels of energy and protein on performance, egg quality, hatchability, fertility and their effect on subsequent offspring live body weight was investigated. a total of 432 japanese quails (13 weeks old) were divided into nine treatments. each treatment comprised of four replicates of twelve birds (9 females and 3 males). nine diets including three levels of metabolizable energy (me) (11.51, 12.41 and 12.77 mj/kg diet) and three levels of crude protein (cp) (180, 200 and 220 g/kg diet) in a 3 × 3 factorial design were formulated. weight gain and egg production were higher in quails fed diets with high level of me (12.77 mj/kg diet) and cp (220 g/kg diet). feed conversion ratio (fcr) improved linearly with the increase in dietary energy level, and the best fcr was obtained by 12.77 mj me/kg diet (p<0.05). increasing energy and protein levels resulted in an increase in egg shell thickness, egg shell strength, albumen and yolk indexes (p<0.01). percentage of hatchability and subsequent offspring live body weight at hatch were significantly affected by dietary me and cp levels (p<0.01). offspring live body weight were higher in chicks from hens fed diets high in energy and protein level. based on the results of the present study, me and cp levels of laying japanese quails diets had significant effects on performance, egg quality and offspring live body weight at hatch.