Table 2.
Data summary and meta-analysis of relevant variables based on all of the selected studies
| Variables | No. of trials | Defaunation group | Faunation group | Meta-analysis | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| n | Mean | SD | n | Mean | SD | I2, % | SMD | P-value | ||
| CH4, L/d | 18 | 126 | 20.8 | 12.4 | 129 | 23.4 | 12.0 | 71.9 | −0.602 | 0.037 |
| Total VFA, mmol/L | 29 | 211 | 78.8 | 29.7 | 212 | 87.1 | 31.3 | 44.2 | −0.549 | < 0.001 |
| Individual VFA molar proportion, % | ||||||||||
| Acetate | 29 | 210 | 67.7 | 5.6 | 211 | 66.3 | 4.3 | 67.8 | 0.358 | 0.083 |
| Propionate | 29 | 210 | 21.0 | 4.8 | 211 | 20.6 | 3.1 | 73.5 | 0.150 | 0.515 |
| Butyrate | 27 | 202 | 8.2 | 2.0 | 203 | 10.2 | 2.8 | 68.3 | −1.026 | < 0.001 |
| A:P | 18 | 78 | 3.6 | 1.6 | 81 | 3.5 | 0.7 | 77.0 | −0.284 | 0.493 |
| Total-tract fiber digestibility, % | ||||||||||
| NDF | 15 | 109 | 55.0 | 11.6 | 109 | 58.1 | 11.8 | 55.7 | −2.063 | < 0.001 |
| ADF | 11 | 82 | 42.8 | 2.7 | 82 | 45.7 | 3.7 | 69.8 | −3.075 | < 0.001 |
n number of animals, I2 percentage of heterogeneity across studies, SMD standardized mean difference, A:P acetate: propionate ratio, NDF neutral detergent fiber, ADF acid detergent fiber