Table 1.

Ingredient composition and calculated chemical composition of experimental diets

Item	Corn-SBM1	Corn-SBM-DDGS1	Wheat-SBM	Wheat-SBM-wheat middlings
Ingredient, %
Corn	71.40	47.55	—	—
DDGS	—	30.00	—	—
Wheat	—	—	73.75	44.88
Wheat middlings	—	—	—	30.00
SBM, 48% CP	24.00	18.00	22.00	21.00
Soybean oil	1.00	1.00	1.00	1.00
Limestone	1.17	1.44	1.40	1.45
Dicalcium phosphate	0.56	0.18	0.14	—
L-Lys HCl, 78% Lys	0.28	0.33	0.21	0.17
DL-Met	0.03	—	—	—
L-Thr	0.06	—	—	—
Vitamin-mineral premix2	0.30	0.30	0.30	0.30
Sodium chloride	0.30	0.30	0.30	0.30
Titanium dioxide	0.40	0.40	0.40	0.40
Phytase premix3, 4	0.50	0.50	0.50	0.50
Calculated values5
NE, kcal/kg	2,476	2,416	2,348	2,247
CP, %	17.38	20.76	21.24	21.31
Ca, %	0.66	0.66	0.66	0.66
Standardized total tract digestible P, %	0.31	0.31	0.31	0.40
Amino acids6, %
Arg	1.01	1.04	1.12	1.23
His	0.42	0.48	0.47	0.49
Ile	0.62	0.69	0.73	0.71
Leu	1.36	2.08	1.30	1.28
Lys	0.98	0.98	0.98	0.98
Met	0.28	0.32	0.27	0.27
Met + Cys	0.56	0.61	0.62	0.61
Phe	0.74	0.87	0.89	0.86
Thr	0.59	0.60	0.60	0.60
Trp	0.18	0.17	0.24	0.24
Val	0.69	0.81	0.80	0.81

¹SBM = soybean meal; DDGS = distillers dried grains with solubles.

²Provided the following quantities of vitamins and micro-minerals per kilogram of complete diet: vitamin A as retinyl acetate, 11,136 IU; vitamin D₃ as cholecalciferol, 2,208 IU; vitamin E as dl-α tocopheryl acetate, 66 IU; vitamin K as menadione dimethylprimidinol bisulfite, 1.42 mg; thiamin as thiamine mononitrate, 0.24 mg; riboflavin, 6.59 mg; pyridoxine as pyridoxine hydrochloride, 0.24 mg; vitamin B₁₂, 0.03 mg; d-pantothenic acid as d-calcium pantothenate, 23.5 mg; niacin, 44.1 mg; folic acid, 1.59 mg; biotin, 0.44 mg; Cu, 20 mg as copper sulfate and copper chloride; Fe, 126 mg as ferrous sulfate; I, 1.26 mg as ethylenediamine dihydriodide; Mn, 60.2 mg as manganese sulfate; Se, 0.3 mg as sodium selenite and selenium yeast; and Zn, 125.1 mg as zinc sulfate.

³The phytase premix contained 200,000 units of microbial phytase (Axtra PHY; Danisco Animal Nutrition-DuPont Industrial Biosciences, Waukesha, WI) per kilogram, which resulted in addition of 1,000 units per kilogram of microbial phytase in the complete diet.

⁴Four additional diets that were identical to the diets above were formulated by including xylanase A in the phytase premix and another four diets were formulated by including xylanase B in the phytase premix. Each of the two xylanases was included in the premixes in quantities that provided 16,000 units of xylanase in the final diet. Both xylanases A and B were experimental xylanases produced by Danisco Animal Nutrition-DuPont Industrial Biosciences (Marlborough, UK).

⁵Calculated from NRC (2012).

⁶Amino acids are indicated as standardized ileal digestible AA.