There are two TI families of proteins in soybeans that inhibit either
trypsin or trypsin and chymotrypsin activity in the gastrointestinal tract,
thus interfering with protein digestion (Norton, 1991). TI concentra-
tions in SBM range from 5 to 8 g/kg (Russett, 2002). Salmonids are
sensitive to TI (Sandholm et al., 1976; Krogdahl et al., 1994). In studies
with rainbowtrout and Atlantic salmon, trypsin production increased as
dietary soy inclusion increased, then decreased as dietary soy inclusion