2. Material and methods
2.1. Preparation of fermented soybean meal
The method used to ferment the soybean meal was described previously (Feng et al.,
2007). Dried soybean meals were soaked with distilled water to maintain moisture content
of 350 g kg−1 for 60 min. Hydrated soybean meals were cooked in a steam tank at
60–70 ◦C for 1 h. Then cooked soybean meals were cooled to room temperature for 1 h,
inoculated with 0.3% A. oryzae 3.042 (±104 counts/g of soybean meal, kindly offered by
Microbial Institute of Zhejiang Province), mixed and fermented in a bed-packed incubator
for 48 h. The nutritional analysis of the FSBM was presented in Table 1. After fermentation,
the level of trypsin inhibitor in SBM decreased compared with FSBM (2.6 mg/g versus
0.0 mg/g).
J. Feng et al. / Animal Feed Science and Technology 134 (2007) 295–303 297
Table 1
Composition of soybean meal (SBM) and fermented soybean meal (FSBM)
Diet (g kg−1) SBM FSBM S.E.M.
Dry matter 882a 912c 0.8
Crude protein1 437a 463b 2.6
Crude fat1 84a 99c 1.6
Calcium1 5.4 5.3 0.2
Phosphorus1 13a 20c 1.2
FSBM, fermented soybean meal; SBM, soybean meal. Values with different letters (a–c) in the same row differ
significantly (P < 0.01). Values with different letters (a–b) in the same row differ significantly (P < 0.05).
1 On a dry matter basis.