Table 2

Concentrations of metabolites identified in various rumen fluids

MetaboliteAvg concn (μM) ± SDa
HGSHFSHDCKNG
Organic acids
    Acetate (mM)78.9 ± 1.969.7 ± 1.163.2 ± 2.1643.7 ± 2.7
    Propionate (mM)15.2 ± 1.015.9 ± 1.315.8 ± 0.914.7 ± 0.3
    Butyrate (mM)8.04 ± 0.69.78 ± 0.510.8 ± 1.111.6 ± 1.5
    Valerate (mM)2.12 ± 0.12.07 ± 0.11.84 ± 0.24.59 ± 0.4
    Isobutyrate (mM)1.32 ± 0.21.33 ± 0.13.61 ± 0.42.26 ± 0.3
    Lactate382 ± 39331 ± 36238 ± 141,400 ± 160
    3-Phenylpropionate453 ± 21397 ± 23862 ± 36766 ± 32
    Acetoacetate141 ± 1684.7 ± 1770.8 ± 6.9564 ± 56
    Formate154 ± 16105 ± 2875.6 ± 15556 ± 99
    Fumarate23.8 ± 4.228.5 ± 8.725.1 ± 4.0266 ± 49
    3-Hydroxybutyrate131 ± 8.080.1 ± 9.476.5 ± 17606.3 ± 14
    Isovalerate726 ± 99681 ± 120533 ± 821,280 ± 98
    Phenylacetate379 ± 26343 ± 22219 ± 6.4708 ± 77
    3-Hydroxyphenylacetate104 ± 4.354.5 ± 2.062.0 ± 3.0293 ± 31
    Succinate77.3 ± 1373.0 ± 1149.1 ± 8.2240 ± 49
    Total organic acids (mM)108.1100.188.483.6
Amino acids
    Alanine231 ± 51184 ± 54109 ± 26748 ± 51
    Aspartate410 ± 51252 ± 9.7159 ± 6.2858 ± 67
    Glutamate479 ± 45341 ± 46256 ± 18811 ± 76
    Glycine143 ± 34200 ± 4560.3 ± 9.9617 ± 79
    Histidine171 ± 24164 ± 6371.4 ± 13423 ± 61
    Isoleucine216 ± 25231 ± 48128 ± 4.11,060 ± 150
    Leucine122 ± 46132 ± 2095.3 ± 13487 ± 84
    Lysine188 ± 30189 ± 17115 ± 241,030 ± 65
    Phenylacetylglycine224 ± 12303 ± 6898.1 ± 20511 ± 22
    Proline418 ± 86399 ± 90289 ± 491,230 ± 45
    Tyrosine159 ± 30162 ± 3382.0 ± 14438 ± 33
    Valine187 ± 12197 ± 3194.1 ± 23549 ± 44
Amines
    Methylamine445 ± 44489 ± 63213 ± 322,240 ± 150
    Cadaverine107 ± 1.8104 ± 4.861.3 ± 7.2514 ± 33
    Dimethylamine148 ± 9.4164 ± 1775.5 ± 2.0213 ± 29
Miscellaneous
    Choline23.0 ± 2.916.9 ± 8.212.1 ± 1.8115 ± 9.2
  • a Data are presented as average values measured in triplicate (metabolite concentrations are presented as μM concentrations [unless stated otherwise in column 1] ± mean standard deviations). Ruminant abbreviations are as defined in Table 1, footnote a.