Table 2.
Definition of traits.
| Trait | Unit | Abbreviation | Formula |
|---|---|---|---|
| Mid-test body weight | kg | BW | Predicted live weight by regression at mid-test |
| Metabolic body weight | Kg0.75 | MBW | BW0.75 |
| Dry matter intake | kg/d | DMI | Daily average of roughage plus pellet dry matter intake |
| Average daily gain | g/d | ADG | Regression coefficient of body weights on time |
| Methane emission rate | g/d | CH4 | Daily average of methane emission spot measures |
| Carbon dioxide emission rate | g/d | CO2 | Daily average of carbon dioxide emission spot measures |
| Feed efficiency ratio | g/kg | ADG/DMI | ADG divided by DMI |
| Residual gain from MBW and DMI | g/d | rwiADG | ADG—expADG where expADG is obtained by the regression of ADG on MBW and DMI |
| Residual intake from MBW and ADG | kg/d | rwgDMI | DMI—expDMI where expDMI is obtained by the regression of DMI on MBW and ADG |
| Methane yield | g/kg | CH4/DMI | CH4 divided by DMI |
| Residual methane from MBW and DMI | g/d | rwiCH4 | CH4—expCH4 where expCH4 is obtained by the regression of CH4 on MBW and DMI |
| Gain to carbon dioxide ratio | g/kg | ADG/CO2 | ADG divided by CO2 |
| Residual gain from MBW and CO2 | g/d | rwcADG | ADG—expADG where expADG is obtained by the regression of ADG on MBW and CO2 |
| Residual carbon dioxide from MBW and ADG | g/d | rwgCO2 | CO2—expCO2 where expCO2 is obtained by the regression of CO2 on MBW and ADG |
| Methane to carbon dioxide ratio | g/kg | CH4/CO2 | CH4 divided by CO2 |
| Residual methane from MBW and CO2 | g/d | rwcCH4 | CH4—expCH4 where expCH4 is obtained by the regression of CH4 on MBW and CO2 |