Models for predicting protein requirements for meat quail

Three experiments were carried out to determine the crude protein requirements for maintenance (CPm) and weight gain (CPg) of meat quail and to develop protein-requirement prediction models. Experiment 1 was conducted to determine CPm by the nitrogen-balance technique. The regression of nitrogen balance on nitrogen intake revealed a CPm requirement of 2.94 g/kg^0.75 /day. Experiment 2 was aimed at determining CPm 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 CPm estimate of 6.63 g/kg^0.75 /day. Experiment 3 was conducted to determine CPg. The regression of body nitrogen from the carcasses on fasted body weight revealed CPg 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).