First-pass extraction of amino acids by the small intestine in pig – How important is it? - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Access content directly
Conference Poster Year : 2022

First-pass extraction of amino acids by the small intestine in pig – How important is it?


The small-intestine is a metabolically very active tissue, able to extract a significant share of dietary amino acids (AA) in first-pass for its own needs. The objective of this study was to gather and analyse existing data on first-pass metabolism in pigs to identify influencing factors. A database was created (n = 20) from in vivo trials, investigating net portal balance (NPB, n = 18) and dual tracer balance (DTB, n = 11) as response variables. Both variables measure the proportion of dietary AA appearing in the portal vein after absorption by the small intestine and that are not metabolized in first-pass. Kruskal-Walis test was used to detect differences in NPB or DTB in between AA and Wilcoxon test was used for pairwise comparisons. For NPB, there was no difference (P = 0.16) in between essential amino acids, while there was for non-essential amino acids (P < 0.05). The average NPB of Glx and Asx was close to zero, while that of Ala exceeded 100%. For Cys, the NPB averaged 45%. A strong variation of NPB among articles was observed, which could not be reduced by expressing the NPB of each AA relative to Lys. Study profiles of NPB were similar among treatments within publications, suggesting a strong study effect. Data obtained with DTB were only available for seven AA and showed a value of 60% for Thr, while it was 100% for Met. The results confirm the disappearance of Glx and Asx across the intestine and a net production of Ala as NH3 acceptor. The important disappearance of Cys might be related to its role as a sulphur donor and the sparing of Met for non-digestive tissues. However, the variation among studies was such that it was not possible to precisely quantify first-pass metabolism, nor it was possible to identify influencing factors.

Dates and versions

hal-03788296 , version 1 (26-09-2022)



Clément Garçon, Nathalie Le Floc'H, Jaap J. van Milgen. First-pass extraction of amino acids by the small intestine in pig – How important is it?. 15. International symposium on digestive physiology of pigs (DPP), May 2022, Rotterdam, Netherlands. Animal - science proceedings, 13 (2), pp.179, 2022, Science for sustainable nutrition - Proceedings of the 15th international symposium on digestive physiology of pigs (DPP2022). ⟨10.1016/j.anscip.2022.03.275⟩. ⟨hal-03788296⟩


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