Table 5.

Effect of dietary CP content on NEAA digestibility

Item	CP contents (g/kg of DM)1					Contrast2
	CR	100	120	140	SEM	RI vs. VI	Linear	Quadratic
Apparent absorption of NEAA (g/d)
Alanine	16.6	28.2	34.0	38.9	0.003	<0.01	<0.01	0.81
Aspartic acid	26.3	43.1	51.2	57.8	0.01	<0.01	0.01	0.87
Cystine	5.2	7.2	70	8.5	1.81	<0.01	0.13	0.25
Glutamic acid	36.3	58.7	70.0	78.3	0.01	<0.01	<0.01	0.78
Glycine	12.5	21.3	26.7	30.0	0.003	<0.01	<0.01	0.54
Proline	12.0	21.3	27.0	29.4	0.002	<0.01	<0.01	0.34
Serine	12.2	19.1	23.4	27.5	0.002	<0.01	<0.01	0.92
Tyrosine	11.7	17.7	20.2	24.2	0.002	<0.01	<0.01	0.60
Apparent digestibility of NEAA (%)
Alanine	66.8	67.5	71.5	70.8	2.35	0.01	0.02	0.05
Aspartic acid	79.1	77.4	81.2	77.6	3.39	0.84	0.93	0.07
Cystine	68.7	64.1	61.1	68.0	11.08	0.34	0.48	0.30
Glutamic acid	72.3	70.7	75.6	73.3	2.12	0.50	0.12	0.02
Glycine	60.6	60.9	66.1	65.6	2.83	0.01	0.01	0.05
Proline	62.3	63.4	69.4	68.5	2.60	<0.01	<0.01	0.02
Serine	69.8	67.6	73.1	72.3	2.26	0.41	0.01	0.04
Tyrosine	68.3	65.3	68.5	67.6	2.68	0.51	0.28	0.26
Total NEAA	68.9	73.4	71.9	70.0	0.02	0.27	0.06	0.03
Total AA
Ap.Ab3 (g/d)	249.8	406.8	476.0	554.0	0.04	<0.01	<0.01	0.89
AD4 (%)	71.2	70.2	74.2	73.4	0.02	0.30	0.06	0.10

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).

³Ap.Ab = apparent absorption.

⁴AD = apparent digestibility.