Table-5.

Effect of amino acid supplementation in a low-protein diet on body weight, body weight gain, feed intake, and feed conversion ratio during a 35-day production period.

Item	Treatmentsa			SEM	p-value
	CON	CP-1%	CP-2%		CON versus treatment	Linear	Quadratic
Initial body weight, g	44.09	44.28	44.04	0.204	0.53	--	--
From 1 to 14 days
Body weight (14 days), g	478.38b	487.09b	502.22a	4.08	0.003	0.001	0.39
Daily weight gain, g	31.02b	31.63b	32.73a	0.30	0.003	0.001	0.38
Daily feed intake, g	34.90a	35.19a	33.95b	0.19	0.002	0.003	0.004
Feed conversion ratio	1.13a	1.11a	1.04b	0.02	0.002	0.001	0.05
From 15 to 28 days
Body weight (28 days), g	1341.44b	1358.73ab	1395.01a	14.53	0.03	0.01	0.48
Daily weight gain, g	61.64	62.26	63.77	0.95	0.15	0.06	0.60
Daily feed intake, g	103.50	103.45	101.00	1.19	0.13	0.08	0.29
Feed conversion ratio	1.68	1.66	1.58	0.04	0.08	0.04	0.36
From 29 to 35 days
Body weight (35 days), g	1901.7b	1905.9b	1945.2a	11.95	0.02	0.01	0.14
Daily weight gain, g	80.03	78.17	78.59	1.94	0.63	0.49	0.52
Daily feed intake, g	139.71a	138.67a	134.95b	1.07	0.01	0.004	0.20
Feed conversion ratio	1.75	1.77	1.72	0.05	0.55	0.55	0.37
From 1 to 35 days
Total body weight gain, g	1857.6b	1861.7b	1901.2a	11.867	0.02	0.01	0.14
Total feed intake, g	2915.7a	2911.7a	2834.0b	13.052	0.001	0.001	0.05
Feed conversion ratio	1.57a	1.56a	1.49b	0.012	0.001	0.001	0.01

^a,bMeans within rows with different letters are different at p<0.05; Tukey’s tests were applied to compare means; SEM=Standard error of the mean.

^aThe experimental diets were formulated to contain 22, 21, and 20 % CP for the starting period, 20, 19, and 18% CP for the growing period, and 18, 17, and 16% CP for the finishing period in CON, CP-1%, and CP-2%, respectively. The CP-1% and CP-2% groups were supplemented with threonine, valine, and tryptophan to meet or exceed the respective levels of the control diet