Table 1.

Ingredient and chemical composition of experimental diets.

Item	Dietary Trp supplementation%
	ZTS	LTS	HTS
Ingredients%
Corn	64.61	64.96	65.37
Soybean meal	19.50	19.00	17.30
Whey powder	4.50	4.50	4.50
Fish meal	5.50	5.50	5.50
Soybean oil	2.40	2.40	3.00
Lysine	0.55	0.55	0.60
Methionine	0.18	0.18	0.20
Threonine	0.18	0.18	0.20
Tryptophan	0.00	0.15	0.75
DCP	0.76	0.76	0.76
Limestone powder	0.52	0.52	0.52
Salt	0.30	0.30	0.30
2Premix	1.00	1.00	1.00
Total	100.00	100.00	100.00
Nutrient levels%
DE (MJ/kg)	14.65	14.63	14.62
CP	18.08	18.05	18.05
Lysine	1.23	1.23	1.23
Methionine + cysteine	0.68	0.68	0.68
Threonine	0.73	0.73	0.73
Tryptophan	0.15	0.30	0.90
Leucine	1.25	1.25	1.25

¹ ZTS: zero Trp supplementation (0% Trp); LTS: low Trp supplementation (0.15% Trp); HTS: high Trp supplementation (0.75% Trp).

²The following minerals and vitamins per kilogram were provided in the premix (as-fed basis): Zn (ZnO), 50 mg; Cu (CuSO₄), 20 mg; Mn (MnO), 55 mg; Fe (FeSO₄), 100 mg; I (KI), 1 mg; Co (CoSO₄), 2 mg; Se (Na₂SeO₃), 0.3 mg; vitamin A, 8,255 IU; vitamin D3, 2,000 IU; vitamin E, 40 IU; vitamin B₁, 2 mg; vitamin B₂, 4 mg; pantothenic acid, 15 mg; vitamin B₆, 10 mg; vitamin B₁₂, 0.05 mg; vitamin PP, 30 mg; folic acid, 2 mg; vitamin K₃, 1.5 mg; biotin, 0.2 mg; choline chloride, 800 mg; and vitamin C, 100 mg.