This study was conducted to investigate the appropriate processing conditions for solid-state
fermented soybean meal (FSBM) using a mixed starter culture ofStreptococcus thermophilus,
Bacillus subtilisMA139, andSaccharomyces cerevisae(Exp. 1), and determine the effect of
FSBM (produced with appropriate conditions) as a partial replacement for soybean meal
(SBM) on growth performance and nutrient digestibility of weanling pigs (Exp. 2). In Exp. 1,
SBM was fermented using different processing conditions, including initial moisture content,
incubation temperature and duration, sugar addition, protease supplementation, and neutral
protease to acid protease ratio. After fermentation, pH value and contents of crude protein,
lactic acid, glycinin, and β-conglycinin in FSBM were determined. Results showed that the
appropriate incubation temperature for FSBM production was 401C. Greater initial moisture
content (60%) and protease supplementation (0.3%) improved nutritional value. The suitable
neutral protease to acid protease ratio was 3:1. Five days of incubation was sufficient for
production of good quality FSBM. Addition of brown sugar did not affect the glycinin, andβ-conglycinin contents in FSBM. In Exp. 2, a total of 72 crossbred piglets (DurocLand
raceLarge White) of an average weight of 8.9 kg were randomly allotted to 2 treatments
with 6 replicate pens and 6 piglets per pen. Piglets were fed either a control diet with 24%
SBM or a test diet with 6% FSBM added at the expense of SBM. Results from Exp. 2 showed
that replacing SBM with 6% FSBM improved average daily gain and average daily feed intake
(Po0.05), while feed conversion ratio was unaltered. The nutrient digestibility and plasma
ureaNconcentration in piglets on the FSBM diet were not different from those fed the SBM
diet. In conclusion, achieving a suitable incubation temperature, greater initial moisture
content, and supplementing with protease are essential to obtain good quality FSBM. Feeding
a diet containing 6% FSBM can result in greater growth performance in weanling pigs,
implying that this new strategy has the potential to be used to produce solid-state FSBM