Table 2.
Genetic correlation (±SE; below diagonal) and phenotypic correlation (±SE; above diagonal) for gas emission parameters within lambs in respiration chambers or portable accumulation chambers or within ewes in portable accumulation chambers
| Trait | BW | CH4 | CO2 | CH4 + CO2 | CH4/(CH4 + CO2) | CH4 |
|---|---|---|---|---|---|---|
| Kg | g/d | g/d | mol/d | mol/mol | g/kg DMI | |
| Respiration chamber, lambs | ||||||
| BW, kg | – | 0.61 (0.01) | 0.78 (0.01) | 0.78 (0.01) | 0.04 (0.02) | 0.003 (0.02) |
| CH4, g/d | 0.83 (0.04) | – | 0.74 (0.01) | 0.77 (0.01) | 0.65 (0.01) | 0.67 (0.01) |
| CO2, g/d | 0.96 (0.01) | 0.84 (0.04) | – | ~1 | −0.05 (0.02) | 0.11 (0.02) |
| CH4 + CO2, mol/d | 0.93 (0.02) | 0.85 (0.04) | ~1 | – | 0.01 (0.02) | 0.15 (0.02) |
| CH4/(CH4 + CO2), mol/mol | 0.09 (0.12) | 0.50 (0.09) | −0.01 (0.13) | 0.01 (0.11) | – | 0.84 (0.01) |
| CH4, g/kg DMI | 0.02 (0.13) | 0.50 (0.10) | 0.06 (0.13) | 0.07 (0.13) | 0.93 (0.02) | – |
| Portable accumulation chamber, lambs | ||||||
| BW, kg | – | 0.43 (0.02) | 0.36 (0.02) | 0.38 (0.02) | 0.22 (0.02) | – |
| CH4, g/d | 0.52 (0.11) | – | 0.41 (0.01) | 0.44 (0.01) | 0.79 (0.01) | – |
| CO2, g/d | 0.55 (0.11) | 0.37 (0.14) | – | ~1 | −0.19 (0.02) | – |
| CH4 + CO2, mol/d | 0.56 (0.11) | 0.41 (0.13) | ~1 | – | −0.16 (0.02) | – |
| CH4/(CH4 + CO2), mol/mol | 0.21 (0.14) | 0.82 (0.05) | −0.21 (0.15) | −0.17 (0.16) | – | – |
| Portable accumulation chamber, ewes | ||||||
| BW, kg | – | 0.31 (0.02) | 0.40 (0.02) | 0.41 (0.02) | −0.07 (0.03) | – |
| CH4, g/d | 0.59 (0.13) | – | 0.26 (0.03) | 0.35 (0.02) | 0.67 (0.02) | – |
| CO2, g/d | 0.65 (0.10) | 0.32 (0.02) | – | ~1 | −0.47 (0.02) | – |
| CH4 + CO2, mol/d | 0.65 (0.10) | 0.33 (0.15) | ~1 | – | −0.45 (0.02) | – |
| CH4/(CH4 + CO2), mol/mol | −0.13 (0.15) | 0.60 (0.02) | −0.60 (0.11) | −0.58 (0.11) | – | – |