Table 3.
Effect of Cut (1–5 where 1, 3 and 5 is the first, second and third cut in the three-cut system, and 2 and 4 is the first and second cut in the two-cut system) and crop (T, Timothy; T + RC, Timothy + red clover; RG, perennial ryegrass) on silage fermentation characteristics averaged across DM and additive treatments (n = 4).
| Cut | Three cuts | Two cuts | SEM | P value | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| T | T + RC | RG | T | T + RC | RG | Cut | Crop | Cut × crop | C1 | C2 | C3 | C4 | C5 | |||
| Lactic acid, g/kg DM | 1st | 35.6 | 33.3 | 38.8 | 22.6 | 18.9 | 23.3 | 11.31 | 0.007 | 0.515 | 0.889 | 0.001 | 0.129 | 0.104 | 0.631 | 0.254 |
| 2nd | 33.3 | 40.7 | 34.2 | 15.7 | 24.9 | 21.6 | ||||||||||
| 3rd | 40.6 | 71.3 | 47.2 | – | – | – | ||||||||||
| Acetic acid, g/kg DM | 1st | 7.44 | 9.95 | 17.0 | 5.89 | 5.44 | 7.91 | 3.319 | 0.069 | 0.262 | 0.831 | 0.011 | 0.068 | 0.396 | 0.111 | 0.273 |
| 2nd | 8.09 | 9.38 | 9.90 | 5.71 | 7.77 | 6.92 | ||||||||||
| 3rd | 10.3 | 16.6 | 12.7 | – | – | – | ||||||||||
| Propionic acid, g/kg DM | 1st | 2.35 | 1.93 | 1.99 | 1.00 | 0.88 | 1.47 | 0.199 | < 0.001 | 0.251 | 0.392 | < 0.001 | < 0.001 | 0.037 | 0.583 | 0.104 |
| 2nd | 1.26 | 0.76 | 0.82 | 0.56 | 0.64 | 0.60 | ||||||||||
| 3rd | 0.81 | 0.73 | 0.75 | – | – | – | ||||||||||
| Butyric acid, g/kg DM | 1st | 7.32 | 8.91 | 8.09 | 3.25 | 3.20 | 5.87 | 1.986 | 0.048 | 0.673 | 0.889 | 0.305 | 0.018 | 0.458 | 0.849 | 0.512 |
| 2nd | 3.37 | 2.58 | 3.89 | 6.03 | 4.19 | 3.25 | ||||||||||
| 3rd | 5.76 | 2.71 | 5.84 | – | – | – | ||||||||||
| Ethanol, g/kg DM | 1st | 2.44 | 3.08 | 1.94 | 2.18 | 1.63 | 1.71 | 0.700 | < 0.001 | 0.374 | 0.964 | < 0.001 | 0.268 | < 0.001 | 0.486 | 0.478 |
| 2nd | 1.28 | 1.74 | 1.29 | 5.27 | 5.11 | 4.51 | ||||||||||
| 3rd | 1.46 | 2.67 | 1.64 | – | – | – | ||||||||||
| Formic acid, g/kg DM | 1st | 5.17 | 5.79 | 6.61 | 4.16 | 3.58 | 3.74 | 2.995 | 0.374 | 0.970 | 1.000 | 0.065 | 0.411 | 0.157 | 0.934 | 0.808 |
| 2nd | 5.72 | 5.35 | 5.01 | 1.47 | 2.69 | 1.37 | ||||||||||
| 3rd | 5.57 | 6.99 | 6.15 | – | – | – | ||||||||||
| pH | 1st | 4.42 | 4.50 | 4.24 | 4.22 | 4.41 | 4.31 | 0.193 | < 0.001 | 0.499 | 0.939 | < 0.001 | 0.639 | < 0.001 | 0.496 | 0.243 |
| 2nd | 4.04 | 4.21 | 4.06 | 4.80 | 4.98 | 5.21 | ||||||||||
| 3rd | 4.08 | 4.19 | 4.16 | – | – | – | ||||||||||
| NH3, g/kg total N | 1st | 45.4 | 40.6 | 38.3 | 39.1 | 29.6 | 36.0 | 8.173 | 0.016 | 0.360 | 0.919 | 0.220 | 0.336 | 0.061 | 0.444 | 0.505 |
| 2nd | 33.1 | 31.9 | 46.8 | 56.9 | 50.4 | 64.3 | ||||||||||
| 3rd | 38.9 | 43.6 | 47.9 | – | – | – | ||||||||||
C1 is the contrast three versus two cuts per season overall; C2 is the contrast three versus two cuts per season, 1st cut; C3 is the contrast three versus two cuts per season, 2nd cut; C4 is the contrast T versus RG; C5 is contrast T versus T + RC.