Evaluation of energy and protein requirement of Japanese quail (Coturnix japonica) during rearing period: Effect onperformance, energy, and nitrogen utilization

This experiment was carried out to determine the optimal level of energy and protein, in grower diet ofJapanese quail. In the first experiment, 720-day old Japanese quails were used in a 3×3 factorialarrangement of dietary treatments that comprised three levels of metabolizable energy (2750, 2850, and2950 Kcal/kg) and three levels of crude protein (24, 26, and 28%) with four replicates per treatment in acompletely randomized design. Feed intake and body weight were measured weekly and feed conversionratio was calculated. Nitrogen retention per unit energy intake And Apparent digestibility metabolizableenergy of diets were measured at 26-28days of age. At 35 d of age, randomly birds selected and killed forevaluation of carcass traits, simultaneously blood samples were collected and assayed for the seraconcentrations of growth hormone. Results indicated that birds fed on diets containing 2850 kcal/kgmetabolizable energy and 26% protein had higher daily weight gain and better feed conversion ratio andcarcass yield (p<0.05). The sera concentration of growth hormone was higher in birds fed on a dietcontaining 2750 kcal/kg metabolizable energy (p<0.05). Nitrogen retention per unit energy intake washigher in birds fed on a diet containing 2850 kcal/kg metabolizable energy and 26% protein (p<0.05). Thisstudy indicated that Japanese quails could grow faster and more efficiently on diet containing 2850 kcal/kgmetabolizable energy and 26% protein. Therefore, these data could be considered as dietary metabolizableenergy and protein requirements for growing Japanese quails.

کلیدواژه ها:

Japanese quail ، metabolizable energy ، nitrogen retention ، performance