Table 3.
PH and in vitro fermentation end-products after 120 h of incubation of PPB silages and wheat straw.
| Parameter | PPB Silage: Straw Percentages | Straw | Substrate p Value |
|||
|---|---|---|---|---|---|---|
| 0% | 5% | 10% | ||||
| pH | 6.86 ± 0.07 A | 6.75 ± 0.04 A | 6.87 ± 0.04 A | 6.63 ± 0.06 B | <0.001 | |
| Acetate | mmol/g OM | 34.75 ± 1.60 D | 46.17 ± 1.04 B | 42.51 ± 1.00 C | 59.64 ± 1.47 A | <0.001 |
| Propionate | “ | 11.24 ± 0.51 D | 17.52 ± 0.33 B | 15.24 ± 0.33 C | 21.90 ± 0.47 A | <0.001 |
| Iso-butyrate | “ | 0.35 ± 0.01 C | 0.39 ± 0.01 B | 0.32 ± 0.01 C | 0.49 ± 0.01 A | <0.001 |
| Butyrate | “ | 3.98 ± 0.28 Bc | 4.60 ± 0.18 Bb | 3.95 ± 0.18 Bc | 6.50 ± 0.25 Aa | <0.001 |
| Iso-valerate | “ | 0.49 ± 0.03 B | 0.67 ± 0.02 A | 0.48 ± 0.02 B | 0.75 ± 0.03 A | <0.001 |
| Valerate | “ | 0.76 ± 0.05 B | 1.03 ± 0.03 A | 0.75 ± 0.03 B | 0.54 ± 0.05 C | <0.001 |
| VFA | “ | 52.78 ± 2.19 D | 70.38 ± 1.41 B | 63.75 ± 1.41 C | 89.80 ± 2.00 A | <0.001 |
| BCFA | % VFA | 1.62 ± 0.06 Aa | 1.52 ± 0.04A Ba | 1.28 ± 0.04 Cc | 1.39 ± 0.05B Cb | <0.001 |
PPB: Prickly pear by-products. VFA: Volatile fatty acids; BCFA: Branched-chain fatty acids (iso-valerate + iso-butyrate/total VFA × 100); OM: Organic Matter. Along the row different capital superscript letters indicate difference for p < 0.01; different lowercase superscript letters indicate difference for p < 0.05.