Table 1.
Fermentation parameters in feces changing from moderate- to high-concentrate feeding
| Parameter | Feeding Phase 1 | SEM | p-Value Phase | |||
|---|---|---|---|---|---|---|
| MC | HCwk2 | HCwk3 | HCwk4 | |||
| Fecal pH (mean) | 7.78 a | 7.51 b | 7.45 b,c | 7.39 c | 0.038 | <0.001 |
| Total SCFA (mmol/L) | 55.7 b | 88.9 a | 83.0 a | 86.0 a | 6.07 | <0.001 |
| Acetate (%) | 75.5 a | 73.9 b | 74.8 | 74.4 | 0.77 | 0.08 |
| Propionate (%) | 14.3 a | 13.4 b | 13.8 a | 13.1 b | 0.29 | 0.01 |
| Butyrate (%) | 4.3 c | 5.3a | 5.2 a | 4.8 b | 0.17 | <0.001 |
| Valerate (%) | 1.14 a | 1.11 a,b | 1.01 b | 0.99 b | 0.05 | 0.05 |
| Caproate (%) | 0.16 b | 2.09 | 0.46 b | 2.49 a | 0.819 | 0.05 |
| iso-Butyrate (%) | 3.9 | 3.9 | 4.3 | 3.8 | 0.24 | 0.48 |
| iso-Valerate (%) | 0.84 a | 0.36 | 0.46 b | 0.38 b | 0.047 | <0.001 |
1 16 dairy cows were fed a 40% concentrate diet (18.8% starch, DM base) for 1wk (MC), followed by four weeks of 60% concentrate diet (27.7% starch, DM base; HCwk1–4). a,b,c Different superscript letters indicate significant difference (p ≤ 0.05) or difference by trend (0.05 < p ≤ 0.1, in parentheses) between the feeding phases. SEM, Standard error of the mean.