Table 1.

Feed formulation and composition of the experimental diets.

Item	0–14 d		15–28 d		29–42 d
	PC 1	NC 1,2	PC 1	NC 1,2	PC 1	NC 1,2
Ingredient (%)
Corn	58.17	58.20	62.75	62.25	64.52	69.00
Soybean meal	36.42	33.27	31.58	28.21	29.36	25.49
DCP 1	1.57	1.57	1.44	1.47	1.24	1.26
Soybean oil	1.70	2.56	2.19	2.54	3.00	2.35
Limestone	1.18	1.18	1.13	1.14	1.05	1.07
Common salt	0.30	0.30	0.30	0.30	0.30	0.30
DL-methionine	0.25	0.24	0.22	0.19	0.18	0.16
Premix 1,3	0.25	0.25	0.25	0.25	0.25	0.25
L-lysine-HCL	0.08	0.09	0.08	0.09	0.02	0.05
Sand	0	2.21	0	1.48	0	0
Calculated nutrient 1 (%)
ME 1 (kcal/kg)	3008	3008	3086	3086	3160	3160
Crude protein	22.00	20.50	20.00	18.50	19.00	17.50
Dig-Lysine	1.18	1.10	1.05	0.97	0.95	0.88
Dig-Methionine	0.58	0.55	0.52	0.48	0.47	0.43
Dig-TSAA	0.88	0.83	0.80	0.74	0.74	0.68
Dig-Threonine	0.78	0.73	0.71	0.65	0.67	0.62
Ca	0.90	0.90	0.84	0.84	0.76	0.76
Non-phytate P	0.45	0.45	0.42	0.42	0.38	0.38
Analyzed nutrient
Crude protein, %	22.24	20.81	20.36	18.25	19.15	17.88
GE 1, kcal/kg	3815	3803	3986	3957	4016	4004

¹ DCP, dicalcium phosphate; ME, metabolizable energy; TSAA, total sulfur amino acid; PC, positive control containing standard crude protein; NC, negative control containing reduced crude protein by 1.5% (equivalent to a reduction of 15 g/kg), GE, gross energy.² The amino acids ratio to lysine remained the same as positive control. ³ Provided per kg of diet: vitamin A (retinyl acetate), 8000 IU; cholecalciferol, 1000 IU; vitamin E (DL-tocopheryl acetate), 20 IU; vitamin K, 0.5 mg; thiamin, 2.0 mg; riboflavin, 8.0 mg; d-pantothenic acid, 10 mg; niacin, 35 mg; pyridoxine, 3.5 mg; biotin, 0.18 mg; folic acid, 0.55 mg; vitamin B12, 0.010 mg; manganese, 120 mg; iodine, 0.70 mg; iron, 100 mg; copper, 8 mg; zinc, 100 mg; and selenium, 0.30 mg.