A study was conducted to determine the standardized ileal digestibility (SID) of AA and calculate NE value for 9 soybean products. Ten ileal-cannulated barrows (30 kg BW) were fed 10 diets in a 10 × 6 Youden square at 2.8 × maintenance requirement for energy. The 10 diets were 9 cornstarch-based with 1 soybean co-product as the sole source of protein, and cornstarch, sucrose, canola oil and soybean product as energy source; and an N-free diet with cornstarch, sucrose, and canola oil as energy source. The ratio of cornstarch to sucrose and canola oil in soybean product diets was identical to the N-free diet to allow calculation of energy digestibility of soybean products by difference. The SID of AA for the soybean products was calculated using the N-free diet. The macronutrient profile of the 9 soybean products ranged from 35.4 to 65.8% CP, 1 to 21% ether extract, and 10.1 to 28.1% NDF. The SID of Lys ranged from 86 to 97% (Table 1). Apparent total-tract digestibility of GE digestibility was lower (P < 0.05) for high-ether extract than low-ether extract soybean products. The NE value ranged from 2.3 to 4.5 Mcal/kg of DM, and did not differ among the soybean products. In conclusion, the soybean products had high SID of AA, and hence they can serve as a good source of AA in swine diets. However, ether extract may hinder energy digestibility in the soybean products. Table 1. Lysine, ether extract (EE), and NDF content; Lys and GE digestibility; and NE value for soybean products fed to growing pigs¹

Item	Soybean products
1	2	3	4	5	6	7	8	9
CP, % DM	51.6	58.1	65.2	60.7	71.8	55.0	50.2	40.8	38.5
Lys, % DM	3.31	3.56	4.19	3.58	4.49	3.33	3.09	2.52	2.32
EE, % DM	1.55	1.18	1.51	2.11	0.98	1.31	1.99	23.3	20.7
NDF, % DM	11.1	13.7	22.7	30.6	22.6	13.1	16.7	12.7	16.6
SID of Lys, %	89.4bc	96.5a	95.8ab	90.6abc	92.1abc	86.2c	95.4ab	91.0abc	86.7c
ATTD2 of GE, %	91.0ab	90.1ab	81.9bc	90.3ab	88.7ab	83.9abc	91.7a	76.4c	76.8c
NE, Mcal/kg of DM	2.92	2.92	2.71	3.01	2.93	2.73	2.97	2.96	2.88

^abcMeans within a row without a common superscript differ (P < 0.01). ¹SEM and P-values are respectively: 2.7 and 0.02 for SID of Lys, 1.2 and 0.01 for ATTD of GE, and 0.13 and 0.58 for NE. ²ATTD = apparent total-tract digestibility.