Table 12. Xylanase matrix value evaluation by the quadratic regression graph

Items	Quadratic regression1)	R2	Body weight (g)			Calculated matrix value2) (kcal/kg)
			1,500 U/kg	3,000 U/kg	4,500 U/kg	1,500 U/kg	3,000 U/kg	4,500 U/kg
Day 14	−0.0008x2 + 0.3078x + 333.43	88.943	346.04	359.21	363.96	46.62	123.22	192.38
Day 24	0.0039x2 + 0.0051x + 807.71	96.665	843.10	867.22	873.48	94.61	122.88	129.21
Day 28	0.0027x2 + 0.4559x + 1,117.2	95.726	1,168.33	1,192.33	1,211.19	77.02	102.53	120.36

Regression was drawn with body weight (x) and growth performance (y); x has a range from 0 to 120 kcal/kg, 0 represents the ME level of the NC-3 diet and 120 represents the ME level of the PC diet for convenience.
Calculated values are calculated by substituting body weight values to estimate the matrix value of xylanase. Estimated values over 120 kcal/kg could be biased.
ME, metabolizable energy; PC, energy sufficient diet.