Impacts of varying dietary energy and crude protein levels on growth, carcase traits and digestibility coefficients of growing Japanese quail (Coturnix Coturnix Japonica) during the summer season

An experiment that included crude protein (CP) levels and metabolisable energy (ME) energy (Kcal/kg diet) in meat-type Japanese quail chicks was conducted to evaluate their impacts on performance, carcase traits, digestibility coefficients and nutritional value during the growing period. A total of 540 one-week-old (16.0 ± 0.60 g) Japanese quail chicks were randomly divided into nine treatment groups in a factorial experimental design (3 × 3), which included three levels of CP and ME (22, 24 and 26%) plus three levels of (2800, 2900, or 3000 Kcal ME/kg diet) during the summer season. The highest values of body weight at marketing age, daily weight gain and best feed conversion during all experimental periods were observed for chicks given 24% CP with a 3000 Kcal ME/Kg diet. A significant (P < 0.01) interaction effect was observed due to energy and protein levels on the digestion coefficients of CP, ether extract (EE), nitrogen-free extract (NFE) and organic matter (OM). Results of digestion coefficients generally coincided with those of growth performance. The interaction effect between dietary energy and protein levels on total digested nutrients (TDN) and ME was significant (P < 0.01). Chicks fed the 3000 Kcal ME/Kg with a 24% CP diet had the highest values of TDN and ME. The interaction between energy and protein levels showed insignificant effects on all carcase traits studied. In conclusion, a dietary energy level of 3000 Kcal ME/Kg with 24% CP is recommended to feed growing Japanese quail from 1–6 weeks of age under summer season conditions. Quail production throughout the world is increasing. Diets with a lower percentage of protein and energy content may be less expensive. An energy level of 3000 Kcal ME/Kg with 24% CP is recommended for growing Japanese quail during summer