Models for predicting protein requirements for meat quail

Three experiments were carried out to determine the crude protein requirements for maintenance ( CP m) and weight gain ( CP g) of meat quail and to develop protein‐requirement prediction models. Experiment 1 was conducted to determine CP m by the nitrogen‐balance technique. The regression of nitrogen balance on nitrogen intake revealed a CP m requirement of 2.94 g/kg 0.75 /day. Experiment 2 was aimed at determining CP m by the comparative‐slaughter technique. Retained nitrogen ( RN ) and nitrogen intake ( NI ) were quantified considering the metabolic weight of the birds. The linear regression of RN on NI provided a CP m estimate of 6.63 g/kg 0.75 /day. Experiment 3 was conducted to determine CP g. The regression of body nitrogen from the carcasses on fasted body weight revealed CP g estimates of 407.68 (0–7 days), 501.76 (8–14 days), 470.40 (0–14 days), 517.44 (15–21 days), 627.20 (22–28 days), 423.36 (29–35 days), and 517.44 mg/g (15–35 days). The protein‐requirement prediction models developed for meat quail aged 0–7, 8–14, 0–14, 15–21, 22–28, 29–35, and 15–35 days were CP  = 2.94.W 0.75  + 0.408.G; CP  = 2.94.W 0.75  + 0.502.G; CP  = 2.94.W 0.75  + 0.470.G; CP  = 2.94.W 0.75  + 0,517.G; CP  = 2.94.W 0.75  + 0.627.G; CP  = 2.94.W 0.75  + 0.423.G; CP  = 2.94.W 0.75  + 0.517.G, respectively, where: W 0.75  =  metabolic weight (kg), and G =  daily weight gain (g).