Table 6.

Estimations of dietary NPP requirements of birds aged 1–42 d using a prediction model.

Phase	Dependent Variable 1	Regression Equation	R2	p-Value	Requirements 2
1–14 d	Body weight gain	y = −26.0771 + 161.7267X − 203.9962X2	0.577	0.001	0.411
	Tibial length	y = 32.8185 + 29.8404X	0.492	0.002	0.409
	ATTDC	y = −559.5571 + 3130.0748X − 3900.9427X2	0.762	0.008	0.394
	Serum Ca	y = −30.3980 + 169.7561X − 212.8219X2	0.471	0.004	0.452
	Serum P	y = −25.6906 + 145.3867X − 182.6667X2	0.323	0.004	0.450
15–42 d	Body weight gain	y = 1.7731 + 8.2290X − 29.6305X2	0.257	0.045	0.466
	ATTDC	y = −210.3100 + 1137.7635X − 1275.5178X2	0.507	0.024	0.469
	Serum albumin	y = 7.2332 + 26.6820X	0.376	0.007	0.462
	Serum P	y = 4.7845 − 5.45001X	0.286	0.013	0.422

¹ ATTDC = apparent total tract digestibility coefficients. ² Predicted requirements = requirements of dietary non-phytate P, %.