Abstract
The present study was performed to evaluate the influence of low crude protein (CP) levels, zinc sources (organic as zinc methionine-Zn-Met and inorganic as zinc oxide-ZnO) and their interactions on growth performance, carcass traits, and blood components of growing Japanese quail. A total of 450 one-wk-old Japanese quail with the same body weights were randomly distributed into 9 groups of 50 birds. The 9-diet treatments comprised 3 levels of CP (20, 22, and 24%) and 3 Zn source (0 g of Zn/kg diet, 0.1 g ZnO/kg diet, and 0.1 g Zn-Met/kg diet). The results obtained from this study showed that there were no significant differences among the groups, except for differences in body weight (BW) and body weight gain (BWG) at 3 to 5 - and 1 to 5 wk of age for quail supplemented with 24% and 20% CP. All the studied biochemical parameters were significantly influenced by different levels of CP and Zn, except urea and creatinine, which were affected by CP levels only. In conclusion, dietary protein level for growing Japanese quails could be reduced to 20% without negative effects on their performance, carcass traits, and blood metabolites.