Table 3.
Genetic and phenotypic correlations (±SE) for gas emission parameters determined using respiration chambers for lambs or portable accumulation chambers (PAC) for lambs and ewes
| Trait | Genotypic correlation | Phenotypic correlation | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| BW | CH4 | CO2 | CH4 + CO2 | CH4/(CH4 + CO2) | BW | CH4 | CO2 | CH4 + CO2 | CH4/(CH4 + CO2) | |
| PAC, lambs vs respiration chamber, lambs | ||||||||||
| BW, kg | 0.90 (0.03) | 0.71 (0.10) | 0.49 (0.13) | 0.51 (0.12) | 0.42 (0.14) | 0.80 (0.01) | 0.34 (0.02) | 0.30 (0.02) | 0.31 (0.02) | 0.12 (0.03) |
| CH4, g/d | 0.63 (0.09) | 0.67 (0.11) | 0.04 (0.17) | 0.08 (0.17) | 0.73 (0.13) | 0.54 (0.02) | 0.27 (0.02) | 0.19 (0.02) | 0.20 (0.02) | 0.14 (0.02) |
| CO2, g/d | 0.79 (0.06) | 0.65 (0.11) | 0.41 (0.13) | 0.43 (0.13) | 0.37 (0.15) | 0.66 (0.01) | 0.29 (0.02) | 0.25 (0.02) | 0.26 (0.02) | 0.11 (0.03) |
| CH4 + CO2, mol/d | 0.82 (0.05) | 0.68 (0.11) | 0.40 (0.13) | 0.42 (0.13) | 0.44 (0.15) | 0.69 (0.01) | 0.32 (0.02) | 0.26 (0.02) | 0.27 (0.02) | 0.12 (0.03) |
| CH4/(CH4 + CO2), mol/mol | 0.08 (0.15) | 0.38 (0.15) | −0.36 (0.18) | −0.33 (0.18) | 0.57 (0.13) | 0.05 (0.03) | 0.08 (0.02) | 0.01 (0.02) | 0.01 (0.02) | 0.08 (0.02) |
| CH4, g/kg DMI | 0.05 (0.16) | 0.34 (0.15) | −0.38 (0.18) | −0.35 (0.18) | 0.54 (0.14) | 0.03 (0.03) | 0.08 (0.02) | 0.01 (0.02) | 0.01 (0.02) | 0.08 (0.02) |
| PAC, ewes vs. respiration chamber, lambs | ||||||||||
| BW, kg | 0.81 (0.08) | 0.56 (0.14) | 0.34 (0.13) | 0.35 (0.13) | 0.03 (0.13) | 0.55 (0.02) | 0.20 (0.03) | 0.22 (0.03) | 0.22 (0.03) | −0.02 (0.03) |
| CH4, g/d | 0.57 (0.11) | 0.62 (0.14) | 0.15 (0.14) | 0.16 (0.14) | 0.32 (0.15) | 0.36 (0.03) | 0.16 (0.03) | 0.13 (0.03) | 0.13 (0.03) | 0.03 (0.03) |
| CO2, g/d | 0.76 (0.09) | 0.58 (0.14) | 0.43 (0.12) | 0.44 (0.12) | −0.03 (0.14) | 0.46 (0.02) | 0.18 (0.03) | 0.21 (0.03) | 0.21 (0.03) | −0.03 (0.03) |
| CH4 + CO2, mol/d | 0.75 (0.09) | 0.59 (0.13) | 0.41 (0.12) | 0.41 (0.12) | 0.01 (0.14) | 0.48 (0.02) | 0.19 (0.03) | 0.22 (0.03) | 0.23 (0.03) | −0.02 (0.03) |
| CH4/(CH4 + CO2), mol/mol | 0.14 (0.14) | 0.33 (0.15) | −0.18 (0.14) | −0.17 (0.14) | 0.50 (0.14) | 0.06 (0.03) | 0.05 (0.02) | −0.01 (0.03) | -0.01 (0.03) | 0.06 (0.02) |
| CH4, g/kg DMI | 0.15 (0.14) | 0.29 (0.15) | −0.22 (0.15) | −0.23 (0.15) | 0.47 (0.14) | 0.05 (0.03) | 0.06 (0.02) | 0.01 (0.02) | 0.01 (0.02) | 0.05 (0.02) |
| PAC, lambs vs PAC, ewes | ||||||||||
| BW, kg | 0.89 (0.07) | 0.65 (0.11) | 0.58 (0.13) | 0.60 (0.13) | 0.36 (0.15) | 0.67 (0.02) | 0.30 (0.03) | 0.31 (0.03) | 0.32 (0.03) | 0.10 (0.03) |
| CH4, g/d | 0.71 (0.12) | 0.99 (0.10) | 0.34 (0.16) | 0.38 (0.16) | 0.85 (0.12) | 0.25 (0.03) | 0.21 (0.02) | 0.10 (0.03) | 0.11 (0.03) | 0.14 (0.02) |
| CO2, g/d | 0.61 (0.12) | 0.44 (0.13) | 0.93 (0.08) | 0.93 (0.08) | −0.25 (0.15) | 0.24 (0.03) | 0.12 (0.03) | 0.31 (0.02) | 0.31 (0.02) | −0.07 (0.03) |
| CH4 + CO2, mol/d | 0.62 (0.12) | 0.46 (0.13) | 0.93 (0.08) | 0.93 (0.08) | −0.23 (0.15) | 0.24 (0.03) | 0.13 (0.03) | 0.31 (0.02) | 0.31 (0.02) | −0.07 (0.03) |
| CH4/(CH4 + CO2), mol/mol | 0.10 (0.14) | 0.38 (0.14) | −0.65 (0.12) | −0.62 (0.12) | 0.85 (0.09) | 0.02 (0.03) | 0.08 (0.03) | −0.17 (0.03) | −0.17 (0.03) | 0.18 (0.020 |