Table 4. Effect of supplemental protease on the ATTD of amino acids with different CP levels in weaned pig at 7 days

Variables	Basal1)		Low		SE	CP		PT2)		p-value
	0%	0.1%	0%	0.1%		HP	LP	0	10	CP	PT	CP × PT
Indispensable amino acids (%)
Threonine	74.94	74.89	76.04	73.92	1.58	74.92	74.98	75.49	74.41	0.967	0.511	0.530
Valine	73.93	74.35	75.61	73.28	1.90	74.14	74.45	74.77	73.82	0.877	0.629	0.488
Isoleucine	73.88	74.69	76.19	74.32	1.87	74.29	75.26	75.04	74.51	0.620	0.784	0.493
Leucine	79.20	80.28	79.45	79.14	1.19	79.74	79.30	79.33	79.71	0.720	0.757	0.577
Phenylalanine	79.83	80.75	79.72	79.79	1.25	80.29	79.76	79.78	80.27	0.683	0.701	0.743
Histidine	88.26	88.88	85.37	88.16	1.52	88.57	86.77	86.82	88.52	0.269	0.293	0.495
Lysine	78.37	78.40	77.82	76.60	1.74	78.39	77.21	78.10	77.50	0.520	0.741	0.728
Arginine	90.00	90.60	86.38	89.63	1.71	90.30	88.01	88.19	90.12	0.217	0.294	0.460
Methionine	75.24	74.18	82.33	83.09	1.73	74.71	82.71	78.79	78.64	0.002	0.934	0.616
Tryptophan	81.15	82.77	77.38	77.18	1.63	81.96	77.28	79.27	79.98	0.021	0.067	0.594
Total	79.64	80.20	79.67	79.48	1.24	79.92	79.58	79.66	79.84	0.787	0.886	0.771
Dispensable amino acids (%)
Aspartic acid	79.60	79.64	79.13	78.34	1.25	79.62	78.74	79.37	78.99	0.498	0.772	0.750
Serine	83.95	84.43	81.97	82.98	1.07	84.19	82.48	82.96	83.71	0.147	0.508	0.809
Glutamic acid	84.50	85.14	82.75	84.02	1.16	84.82	83.39	83.63	84.58	0.248	0.432	0.792
Proline	84.61	85.47	83.20	84.28	1.22	85.04	83.74	83.91	84.88	0.317	0.451	0.930
Glycine	73.30	73.10	74.34	71.61	2.28	73.20	72.98	73.82	72.36	0.923	0.947	0.596
Alanine	69.09	69.45	71.92	67.96	2.73	69.27	69.94	70.51	68.71	0.512	0.528	0.451
Tyrosine	75.84	76.80	76.07	74.85	1.95	76.32	75.46	75.96	75.83	0.671	0.948	0.590
Cysteine	83.87	84.20	82.18	81.82	1.16	84.04	82.00	83.03	83.01	0.117	0.992	0.775
Total	80.71	81.15	80.02	79.84	1.16	80.93	79.93	80.37	80.50	0.410	0.912	0.797

Basal, diet containing 18.78% CP; Low, diet containing 16.92% CP.
PT0, non-supplementation of protease; PT10, supplementation of 0.1% protease.
ATTD, apparent total tract digestibility; CP, crude protein; PT, protease; HP, high protein; LP, low crude protein.