TABLE 4.
Fermentations parameters for consecutive batch culture 1 (CBC1; Experiment 2).
|
Time point (hours) |
P value |
||||||||||||
| Inoculum | 6 | 12 | 18 | 24 | 30 | 36 | 42 | 481 | SEM | Time | Inoculum | Time*Inoculum2 | |
| Gas volume (ml) | G | 18.3a | 56.3a | 85.8a | 132.6a | 153.0 | 176.9 | 185.7 | 211.7 | 18.17 | <0.001 | <0.001 | 0.005 |
| B | 13.4b | 52.6a | 79.8 | 116.6b | 150.2 | 166.9 | 186.9 | 199.3 | |||||
| M | 7.8c | 44.6b | 75.7b | 118.2b | 146.9 | 178.1 | 195.6 | 213.0 | |||||
| pH | G | 6.60a | 6.64a | 6.69 | 6.66a | 6.66a | 6.63a | 6.59a | 6.57 | <0.001 | <0.001 | <0.001 | 0.006 |
| B | 6.63b | 6.67b | 6.69 | 6.69b | 6.66a | 6.66b | 6.63b | 6.57 | |||||
| M | 6.65c | 6.69b | 6.69 | 6.71b | 6.69b | 6.65ab | 6.62b | 6.58 | |||||
| NH3-N (mg/ml) | G | 1.44 | 1.41 | 1.36 | 1.37 | 1.38 | 1.45 | 1.47 | 0.002 | 0.072 | <0.005 | (0.595) | |
| B | 1.45 | 1.45 | 1.46 | 1.43 | 1.41 | 1.50 | 1.45 | ||||||
| M | 1.38 | 1.31 | 1.37 | 1.43 | 1.45 | 1.42 | 1.37 | ||||||
| MCP (μg/ml) | G | 92.9 | 166.4 | 282.3 | 456.0 | 501.8 | 595.0 | 699.6 | 41.22 | <0.001 | 0.091 | (0.172) | |
| B | 87.8 | 232.1 | 254.8 | 323.9 | 479.9 | 405.6 | 589.3 | ||||||
| M | 109.8 | 154.3 | 203.7 | 381.4 | 433.0 | 630.6 | 637.6 | ||||||
| tVFA (mM) | G | 61.4 | 101.7 | 135.3 | 177.5 | 166.0 | 171.2 | 196.0 | 7.98 | <0.001 | 0.080 | (0.053) | |
| B | 57.1 | 97.9 | 139.7 | 153.7 | 214.7 | 199.2 | 195.8 | ||||||
| M | 56.5 | 87.4 | 126.1 | 137.4 | 153.1 | 199.5 | 193.2 | ||||||
| Acetate (mM) | G | 36.8 | 51.7 | 67.3 | 89.4 | 105.2 | 109.5 | 125.1 | 0.43 | <0.001 | 0.284 | (0.275) | |
| B | 42.0 | 55.1 | 68.4 | 89.2 | 101.3 | 113.4 | 127.4 | ||||||
| M | 36.9 | 49.3 | 69.5 | 91.3 | 99.6 | 114.1 | 127.0 | ||||||
| Propionate (mM) | G | 16.7 | 31.4 | 43.2 | 66.5a | 32.9a | 35.2 | 40.6 | 1.43 | <0.001 | 0.030 | <0.001 | |
| B | 8.1 | 33.9 | 45.1 | 26.4ab | 77.5b | 35.0 | 39.7 | ||||||
| M | 7.6 | 29.2 | 44.0 | 26.7b | 30.1a | 36.3 | 40.3 | ||||||
| Butyrate (mM) | G | 13.0 | 18.6 | 24.8 | 39.0a | 27.9a | 26.5 | 30.2a | 0.65 | <0.001 | 0.001 | <0.001 | |
| B | 7.0 | 18.1 | 26.2 | 21.4c | 50.1b | 26.2 | 28.6a | ||||||
| M | 7.0 | 16.3 | 20.9 | 19.4b | 23.4c | 23.9 | 25.9b | ||||||
With the exception of pH, mean values shown are normalized for substrate DM (1 g) added to the model. G, Good; B, Bad; M, Mix rumen fluid used as inoculum; SEM, standard error of the mean; NH3-N, ammonia-nitrogen; MCP, microbial crude protein; tVFA, total volatile fatty acids. 1Not all parameter means are shown at 48 h due to experimental error in preparation of these samples 2Where an interaction was not significant (P-values shown in brackets), it was removed from the analysis and the model was re-run. a–cMeans within a column that do not share a common superscript are significantly different (p < 0.05).