Ph D Thesis Amelie Deglaire - TEL

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(Buraczewska, 1979); however, Asche et al. (1989) reported that gut endogenous
enzymes are hydrolysed rapidly, because little soluble protein corresponding to the MW
of pancreatic enzymes was detected in ileal digesta. Taverner et al. (1981) commented
that the high amounts of proline, glycine, glutamic acid and aspartic acid recovered in
ileal digesta might result from their slow intestinal absorption.
Table 9. Comparison of the amino acid (AA) composition of ileal endogenous nitrogen
(N) with endogenous nitrogenous secretions in the small intestine of pigs.
Reference
Ileal
Source of N
endogenous N Pancreas Bile Ileal bacteria Mucins
Jansman et al,
2002
Corring et al,
1984
Juste,
1982
Dugan et al.,
1994
Lien et al.,
1997
g/100 g AA g/100 g AA g/100 g AA g/100 g AA g/100 g AA
Threonine 6.1 5.2 0.3 4.8 16.4
Valine 4.9 7.2 0.3 6.5 5.9
Isoleucine 3.5 5.9 0.2 6.5 3.0
Leucine 5.4 8.3 0.4 9.9 5.7
Phenylalanine 3.8 4.4 0.2 6.6 3.5
Tyrosine 3.6 5.7 0.2 4.6 3.2
Lysine 4.3 5.1 0.3 8.0 2.8
Histidine 1.9 2.6 0.2 2.6 1.7
Serine 6.1 6.9 0.3 5.1 10.9
Glutamic acid 12.2 10.3 1.1 9.5 10.1
Alanine 5.4 5.4 - 6.4 7.4
Proline 15.8 5.0 0.3 - 12.0
Arginine 4.8 5.1 0.3 7.3 3.5
Aspartic acid 8.4 12.5 0.4 14.5 7.8
Glycine 10.3 6.2 95.0 4.8 5.5
Methionine 1.2 1.1 0.1 1.2 0.8
Cysteine 2.1 3.4 0.6 1.9 -
Basal ileal endogenous N and IAA losses (Rowan et al., 1993; Fuller & Garlick, 1994;
Moughan et al., 2005) represent a significant proportion of the daily dietary requirement,
being 11% for N and 9–19% for IAA, except for threonine for which the ileal loss
amounts to some 28% of requirement (FAO/WHO/UNU, 2007). Whether endogenous N
entering the colon represents an actual loss for the body is still under discussion,
depending on the colonic capacity to (re)absorb AA and on the nutritional significance of
this reabsorption (Blachier et al., 2007), as discussed in the preceding section.