Table 2.
Effects of antimethanogenic compounds on VFA concentrations in the ruminal cultures
| VFA(s) | Mean concn (μmol ml−1) witha: |
SEM | P value | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| PA | EB | ETB | 2NEOH | NE | BES | SN | C | |||
| Acetate | 41.58 c | 72.85 a,b | 68.41 a,b | 26.50 d | 65.44 b | 78.18 a | 46.74 c | 66.75 a,b | 2.87 | <0.0001 |
| Propionate | 5.67 c | 27.44 a | 27.20 a | 4.93 c | 26.18 a | 17.69 b | 5.49 c | 26.94 a | 0.94 | <0.0001 |
| Butyrate | 3.20 b | 7.26 a | 8.84 a | 2.69 b | 7.39 a | 8.44 a | 2.94 b | 7.33 a | 0.40 | <0.0001 |
| Valerate | 0.24 b,c | 0.33 b,c | 0.38 a,b | 0.20 c | 0.28 b,c | 0.24 b,c | 0.20 c | 0.47 a | 0.03 | 0.0003 |
| Isobutyrate | 0.33 c | 0.45 b,c | 0.64 a,b,c | 0.27 c | 0.80 a,b | 0.65 a,b,c | 0.27 c | 0.87 a | 0.11 | 0.0008 |
| Isovalerate | 0.26 b | 0.33 b | 0.45 a,b | 0.21 b | 0.80 a | 0.68 a,b | 0.19 b | 0.81 a | 0.11 | 0.0017 |
| Total VFAs | 51.28 b | 108.66 a | 105.92 a | 34.80 c | 100.89 a | 105.88 a | 55.84 b | 103.17 a | 3.96 | <0.0001 |
| Acetate/propionate | 7.32 b | 2.66 e | 2.52 e | 5.37 c | 2.51 e | 4.43 d | 8.57 a | 2.48 e | 0.14 | <0.0001 |
a
PA, propynoic acid; EB, ethyl-2-butynote; ETB, ethyl trans-2-butenoate; 2NEOH, 2-nitroethanol; NE, nitroethane; BES, 2-bromoethanesulphonate; SN, sodium nitrate (SN); C, control containing no inhibitor. Means within rows with different letters differ significantly (P < 0.05).