Table 3.
Selected enteric CH4 prediction equations from the literature evaluated in present study with emissions expressed per kilogram of DM intake.
| Reference | Equation No. | Equations 1 | |
|---|---|---|---|
| [29] | 5 | CH4 (g/kg DMI) | =(18 + 22.5 × DMI)/DMI |
| [6] | 6 | =(1.3 + 11.2 × DE/GE + FL × (2.37 − 5 × DE/GE)/100 × GE × DMI/0.05565/DMI | |
| [26] | 7 | =(DE × DMI × (0.094 + 0.028 × (FADF/ADF × DMI)) − 2.453 × (FL − 1))/0.05565/DMI | |
| [26] | 8 | =(DE × DMI × (0.096 + 0.035 × (FDMI/DMI)) − 2.298 × (FL − 1))/0.05565/DMI | |
| [4] | 9 | =(56.27 − (56.27 + 0) × e(−0.028 × DMI))/0.05565/DMI | |
| [4] | 10 | =(45.89 − (45.89 + 0) × e(−0.003 × ME × intake))/0.05565/DMI | |
| [30] | 11 | =(74.43 − (74.43 + 0) × e(−0.0163 × DMI))/0.05565/DMI | |
| [30] | 12 | =(7.16 − 0.101 × DMI)/100 × GE × intake/0.05565/DMI | |
| [18] | 13 | =((0.877 − 14.66 × ME/GE + 13.55 × DE/GE + 0.457 × FDMI/DMI + 4.153 × NDF/1000 − 7.47 × ADF/1000) × GE × DMI + 0.8) × 0.003954/0.05565/DMI |
1 DMI = dry matter intake (kg/day); DE = digestible energy (MJ/kg DM); ME = metabolizable energy (MJ/kg DM); GE = gross energy (MJ/kg DM); FL = multiples of ME intake over maintenance calculated from AFRC (1993); NFC = non-fibre carbohydrate (kg/day); HC = hemicellulose (kg/day); C = cellulose (kg/day); ADF = acid detergent fibre (g/kg DM); FADF = forage ADF (kg/day); FDMI = forage DMI (kg/day); NDF = neutral detergent fibre (g/kg DM).