Table 3. Growth performance and nitrogen excretion of experiment diets

Item	CP 20.0%	CP 18.5%¹⁾²⁾			CP 17.0%¹⁾²⁾			SEM	p-value
Item	CP 20.0%	LP	+11 AA	+13 AA	LP	+11 AA	+13 AA	SEM	p-value
Growth performance³⁾
Grower period
BW (g)	656^a	531^bc	650^a	638^a	475^c	616^ab	655^a	21.4	< 0.001
BWG (g)	490^a	365^bc	484^a	472^a	309^c	451^ab	490^a	19.9	< 0.001
FI (g)	710^ab	610^bc	699^ab	678^abc	583^c	687^abc	721^a	24.9	0.003
G:F (g/kg)	691^a	598^b	693^a	696^a	529^c	655^ab	678^a	13.7	<.0001
Finisher period
BW (g)	1,188^a	1,019^bc	1,174^ab	1,169^ab	903^c	1,105^ab	1,133^ab	36.4	< 0.001
BWG (g)	532^a	488^ab	525^a	532^a	428^b	488^ab	478^ab	20.9	0.015
FI (g)	803	752	780	810	708	751	763	26.0	0.137
G:F (g/kg)	663^ab	651^ab	672^a	657^ab	604^b	650^ab	625^ab	14.6	0.041
Overall period
BWG (g)	1,022^a	854^bc	1,008^ab	1,004^ab	738^c	939^ab	968^ab	35.1	< 0.001
FI (g)	1,513^a	1,362^ab	1,479^ab	1,488^ab	1,291^b	1,438^ab	1,485^ab	45.3	< 0.001
G:F (g/kg)	676^a	627^ab	682^ab	674^ab	570^b	652^ab	651^ab	10.1	< 0.001
N excretion³⁾
Coefficient	0.199^b	0.275^a	0.205^b	0.215^b	0.303^a	0.211^b	0.191^b	0.0098	< 0.001
Amount (g)	4.6^ab	5.1^a	4.3^ab	4.4^ab	4.9^ab	3.9^b	3.9^b	0.25	0.010

LP diet was not supplemented with AA, and the overall AA were 14.5 % and 21.7% less compared to requirements in 18.5% CP and 17.0% CP diet, respectively.
LP diets supplemented with 11 AA (arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, and cysteine) were formulated to meet requirement. LP diets with 13 AA were obtained by supplementing glutamic acid and glycine to LP diets supplemented with 11 AA at the expense of corn-starch.
Each mean represents five observations.
Means within a row without a common superscript differ (p < 0.05).
CP, crude protein; LP, low protein; AA; amino acid; BW, body weight; BWG, body weight gain; FI, feed intake; G:F, gain to feed ratio; N, nitrogen.