Table 2.
The 3-NOP effects compared with control period on CH4 and H2 production, dry matter intake, live weight, daily weight gain and fermentation parameters in steers fed at forage diet (Rhodes grass hay).
| Control | 3-NOP | SEMd | P-value | |
|---|---|---|---|---|
| DMI in pens (kg) | 7.7 | 7.6 | 0.22 | 0.32 |
| DMI in chambers (kg) | 6.6 | 7.4 | 0.37 | 0.035 |
| LW (kg) | 487 | 499 | 9.21 | 0.003 |
| DWG (kg)a | −0.040 | 0.571 | 0.09 | 0.012 |
| CH4 (g/d) | 149 | 104 | 1.38 | 0.016 |
| CH4 (g/kg DMI) | 22.9 | 14.2 | 1.0 | 0.005 |
| H2 (g/day) | 0.004 | 0.004 | 0.001 | 0.77 |
| Ym (%)b | 7.3 | 4.5 | 0.32 | 0.005 |
| pH | 6.87 | 6.96 | 0.06 | 0.71 |
| DM degradability % (24 h)c | 33.7 | 31.3 | 0.49 | 0.049 |
| DM degradability % (48 h)c | 40.4 | 38.1 | 0.42 | 0.07 |
| NH3-N (mg/100 mL) | 22.3 | 27.8 | 2.13 | 0.06 |
| Total SCFA, (mM) | 102 | 86.6 | 8.7 | 0.12 |
| Individual SCFA (mol/100 mol) | ||||
| Acetate | 73.5 | 74.4 | 0.38 | 0.016 |
| Propionate | 16.1 | 15.9 | 0.33 | 0.60 |
| i-Butvrate | 0.9 | 1.3 | 0.07 | 0.039 |
| Butvrate | 6.7 | 5.0 | 0.42 | 0.009 |
| i-Valerate | 1.2 | 1.7 | 0.05 | 0.001 |
| Valerate | 1.2 | 1.5 | 0.07 | 0.11 |
| Caproate | 0.37 | 0.23 | 0.02 | 0.001 |
| A:P | 4.6 | 4.7 | 0.11 | 0.28 |
| Ruminal metabolites by NMR | ||||
| (μmol/L rumen fluid) | ||||
| Glucose | 24 | 17 | 4.54 | 0.49 |
| Maltose | 11 | 5.6 | 1.13 | 0.15 |
| Phenyl acetate | 134 | 159 | 12.9 | 0.16 |
| Dimethyl sulfone | 20 | 113 | 3.84 | 0.001 |
| N,N-Dimethylglycine | 31 | 87 | 19.1 | 0.21 |
| Trimethylamine | 334 | 1242 | 137 | 0.016 |
| Dimethylacetamide | 133 | 321 | 34.5 | 0.029 |
| Ethanol | 49 | 54 | 4.02 | 0.10 |
| Methanol | 70 | 118 | 17.5 | 0.14 |
aDWG for the control period corresponds to the period of time where the animals were adapted to the diet (30 days), bMethane conversion rate (Ym) = % GEI lost as CH4. cIn sacco degradability of Rhodes grass hay. dSEM, standard error of the mean.