Table 2.
Effect of breed type and pasture type on voluntary dry matter intake (DMI) and methane (CH4) emissions by weaned lambs (where WM, Welsh Mountain; TexX, Texel cross; MLW, metabolic live weight)
| Ryegrass | Permanent pasture | P value* | |||||
|---|---|---|---|---|---|---|---|
| WM | TexX | WM | TexX | s.e.d. | Breed | Pasture | |
| Weight of lambs at start (kg) | 27 | 35 | 26 | 34 | 1·2 | <0·001 | 0·307 |
| DMI (g/day) | 931 | 1041 | 705 | 758 | 74·7 | 0·275 | <0·001 |
| DMI (g/kg MLW) | 78 | 73 | 61 | 53 | 4·7 | 0·168 | <0·001 |
| CH4 emitted (g/day) | 15 | 17 | 12 | 14 | 1·1 | 0·035 | <0·001 |
| CH4 emitted (g/kg MLW) | 1·2 | 1·2 | 1·0 | 1·0 | 0·07 | 0·651 | <0·001 |
| CH4 emitted (g/kg DMI) | 16·1 | 16·7 | 16·7 | 18·8 | 0·87 | 0·116 | 0·004 |
| CH4 emitted (kg/year)† | 5·4 | 6·3 | 4·3 | 5·1 | 0·41 | 0·035 | <0·001 |
| CH4-E/GE intake (MJ/MJ) | 0·052 | 0·054 | 0·053 | 0·059 | 0·0028 | 0·120 | 0·018 |
GE, gross energy
*
There were no significant interaction effects.
†
Estimated using the Tier 1 approach (Dong et al. 2006).