Six barrows of an average initial BW 27.5±1.2 kg were used. Each pig was fitted with two cannulas in different segments of the small intestine: pig 1 in the duodenum (CI) and upper jejunum (C2), pig 2 in C2 and the lower jejunum (C3), pig 3 in C2 and C3, pig 4 in CI and the terminal ileum (C4), pig 5 in C3 and C4, pig 6 in CI and C4. Pigs were also fitted with one catheter in the vena jugularis for blood sampling and with a second one in the arteria carotis for continuous infusion of 15 N-leucine (4.2 mg/kg°7 5 BW/d). Pigs were used in a crossover design experiment with three treatments and three periods of digesta collection (36 h) and blood sampling (36 h). Maize starch-based diets that contained: soyabean concentrate (SC), a mixture of toasted and untoasted soyabean meal (mSBM) of a high trypsin inhibitor activity, or rapeseed cake (RC) of a high NDF