Table 4.

Effect of dietary CP content on EAA digestibility

Item	CP contents (g/kg DM)1					Contrast2
	CR	100	120	140	SEM	RI vs. VI	Linear	Quadratic
Apparent absorption of EAA (g/d)
Arginine	12.7	20.5	23.8	27.3	0.002	<0.01	<0.01	0.91
Histidine	5.4	8.3	9.7	11.2	0.001	<0.01	0.02	0.91
Isoleucine	13.1	21.8	24.5	28.7	0.002	<0.01	<0.01	0.67
Leucine	23.8	39.1	45.1	52.9	0.004	<0.01	<0.01	0.78
Lysine	17.5	30.1	33.3	43.5	0.004	<0.01	<0.01	0.21
Methionine	5.5	8.6	10.1	11.8	0.001	<0.01	<0.01	0.83
Phenylalanine	12.1	19.5	21.6	26.7	0.002	<0.01	<0.01	0.45
Threonine	10.7	17.5	21.0	24.9	0.002	<0.01	<0.01	0.87
Tryptophan	1.9	2.7	3.8	3.92	0.001	<0.01	<0.01	0.12
Valine	14.5	22.0	24.0	28.7	0.003	<0.01	0.05	0.61
Apparent digestibility of EAA (%)
Arginine	76.6	76.4	79.7	78.9	1.76	0.16	0.10	0.11
Histidine	78.0	75.1	80.4	78.7	2.05	0.93	0.07	0.05
Isoleucine	72.0	72.8	74.8	74.8	1.94	0.07	0.15	0.39
Leucine	74.2	73.5	77.1	77.1	1.85	0.13	0.01	0.14
Lysine	71.1	71.1	73.1	75.1	4.41	0.49	0.26	0.99
Methionine	81.9	80.5	83.4	83.5	1.78	0.61	0.05	0.26
Phenylalanine	72.5	71.9	74.5	74.7	2.13	0.44	0.13	0.43
Threonine	64.1	63.7	68.3	67.4	2.87	0.21	0.12	0.18
Tryptophan	68.7	61.9	73.1	69.2	5.16	0.83	0.07	0.03
Valine	70.9	68.7	72.3	71.5	2.76	0.95	0.28	0.33
Total EAA	72.7	71.8	75.1	75.1	0.02	0.34	0.07	0.27

¹Treatments: RI = restricted intake to 1.2% BW containing 120 g of CP/kg of DM; 100, 120, and 140 = voluntary intake containing 100, 120, and 140 g of CP/kg of DM, respectively.

²RI vs. VI = restricted intake vs. voluntary intake (100, 120, and 140 CP g of CP/kg of DM).