Table 4.
Effects of different levels of COS on rumen fermentation parameters of beef cattle.
| Items | Dietary COS Level, Feeding Basis | SEM | p-Value | |||||
|---|---|---|---|---|---|---|---|---|
| CON | 0.02% COS |
0.04% COS |
0.08% COS |
Main Effect | Linear | Quadratic | ||
| pH | 6.42 c | 6.43 c | 6.46 b | 6.49 a | 0.007 | <0.01 | 0.858 | <0.01 |
| NH3-N (mg/dL) | 7.98 a | 7.93 a | 7.69 b | 7.35 c | 0.090 | <0.01 | 0.739 | <0.01 |
| MCP (mg/mL) | 0.59 b | 0.59 b | 0.61 ab | 0.62 a | 0.010 | 0.104 | 0.733 | <0.01 |
| Total VFA (mmol/mL) | 112.53 | 113.09 | 113.83 | 113.43 | 1.249 | 0.104 | 0.591 | 0.557 |
| Acetate (mmol/mL) | 68.95 a | 68.15 ab | 67.37 ab | 66.70 b | 0.897 | <0.01 | 0.584 | 0.07 |
| Propionate (mmol/mL) | 25.83 b | 27.13 a | 27.66 a | 27.66 a | 0.524 | <0.01 | 0.059 | <0.01 |
| Isobutyrate (mmol/mL) | 0.72 a | 0.69 b | 0.66 c | 0.65 c | 0.008 | <0.01 | 0.272 | <0.01 |
| Butyrate (mmol/mL) | 13.74 b | 13.76 b | 14.91 a | 15.23 a | 0.287 | 0.635 | 0.880 | <0.01 |
| Isovalerate (mmol/mL) | 1.48 | 1.51 | 1.47 | 1.48 | 0.036 | <0.01 | 0.410 | 0.467 |
| Valerate (mmol/mL) | 1.82 a | 1.85 a | 1.76 b | 1.71 b | 0.027 | 0.76 | 0.334 | <0.01 |
| Acetate/propionate | 2.67 a | 2.51 b | 2.43 b | 2.42 b | 0.044 | <0.01 | 0.042 | <0.01 |
In the table, the superscript “a–c” represents the differences in data between the treatment groups. Different letters indicate differences between the groups (p < 0.05), while the same or no letters indicate no significant differences (p > 0.05); SEM, standard error of the mean. pH, potential of hydrogen; MCP, microbial protein.