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Influence of short‐chain fatty acids on ammonia absorption across the rumen wall in sheep
Author(s) -
Bodeker D,
Shen Y,
Kemkowski J,
Holler H
Publication year - 1992
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.1992.sp003597
Subject(s) - rumen , ammonia , incubation , absorption (acoustics) , lactic acid , chemistry , fatty acid , biochemistry , short chain fatty acid , metabolism , food science , biology , bacteria , fermentation , butyrate , materials science , composite material , genetics
The effects of short‐chain fatty acids (SCFA) on ammonia net absorption from the sheep rumen in vivo and on ammonia transport across rumen wall mucosa in vitro were studied. Ammonia net absorption was directly, though in a non‐linear manner, correlated with the SCFA concentration in the artificial rumen fluid. Almost 70% of total ammonia absorption was dependent upon the presence of SCFA when 12 mmol l‐1 ammonia and 67.5 mmol l‐1 SCFA were present. Lactic acid was ineffective. Incubation experiments showed that mucosal disappearance and serosal appearance of ammonia were reduced by 38% and 32%, respectively, when SCFA (63 mmol l‐1) were replaced by lactic acid. The SCFA effect was independent of the type of SCFA used. In part of the experiments up to 54% of the ammonia taken up by the tissue was not recovered in the serosal incubation solution and must have been metabolized in the mucosa.