Table 4. In situ ruminal dry matter degradation kinetics of fresh winter forage rape and fresh perennial ryegrass a .
| Degradation parameters | Forage rape | Perennial ryegrass | P c |
|---|---|---|---|
| (n = 4) b | (n = 4) | ||
| Period 1 | |||
| Soluble fraction A (g/kg DM d ) | 562 ±10 | 539 ±9 | 0.087 |
| Potentially degradable fraction B (g/kg DM) | 418 ±12.4 | 403 ±12.4 | 0.377 |
| Indigestible fraction C (g/kg DM) | 21 ±4.3 | 59 ±4.3 | <0.001 |
| DM degradation rate k (/h) | 0.142 ±0.0046 | 0.071 ±0.0046 | <0.001 |
| Period 2 | |||
| Soluble fraction A (g/kg DM) | 529 ±9 | 489 ±9 | 0.002 |
| Potentially degradable fraction B (g/kg DM) | 441 ±12.4 | 434 ±12.4 | 0.729 |
| Indigestible fraction C (g/kg DM) | 30 ±4.3 | 77 ±4.3 | <0.001 |
| DM degradation rate k (/h) | 0.135 ±0.0046 | 0.077 ±0.0046 | <0.001 |
a in situ incubations conducted in the rumens of two cows fed perennial ryegrass. Soluble fraction A was calculated from dry matter disappearance at 0 h.
b The number of field replicates of forage samples. Values are means ± SEM.
c P value for the difference between forage rape and perennial ryegrass.
d Dry matter.