Table 5.
Effect of different gossypol addition levels on rumen microbial population of two rations after 48 h of incubation (log10 gene copy number/ mL of DNA extract).
| Item | Ration | SEM 2 | Gossypol (mg/g) | SEM 2 | p-Value | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HF 1 | LF 1 | 0 | 0.25 | 0.5 | 0.75 | Ration | Dose | I 3 | L 3 | Q 3 | |||
| F. succinogenes | 6.75 a | 6.50 b | 0.025 | 7.15 a | 6.34 d | 6.48 c | 6.61 b | 0.034 | <0.01 | <0.01 | 0.05 | <0.01 | <0.01 |
| R. flavefaciens | 6.78 | 6.68 | 0.080 | 6.67 b | 6.73 b | 6.41 b | 7.11 a | 0.110 | 0.41 | <0.01 | 0.99 | 0.08 | 0.02 |
| R. albus | 6.32 | 6.25 | 0.021 | 6.42 a | 6.28 b | 6.24 b | 6.21 b | 0.026 | 0.07 | <0.01 | 0.82 | <0.01 | 0.11 |
| B. fibrisolvens | 8.50 b | 8.58 a | 0.016 | 8.72 a | 8.54 b | 8.49 b | 8.40 c | 0.022 | <0.01 | <0.01 | 0.60 | <0.01 | 0.11 |
| P. ruminicola | 7.18 b | 7.26 a | 0.022 | 7.40 a | 7.01 d | 7.25 b | 7.14 c | 0.028 | 0.03 | <0.01 | 0.02 | <0.01 | <0.01 |
| S. ruminantium | 6.09 b | 6.20 a | 0.028 | 6.23 a | 6.05 b | 6.15 ab | 6.15 ab | 0.034 | 0.01 | 0.06 | 0.62 | 0.51 | 0.06 |
| Protozoa | 4.97 a | 4.89 b | 0.016 | 4.76 c | 4.87 b | 4.94 b | 5.15 a | 0.022 | <0.01 | <0.01 | 0.82 | <0.01 | 0.07 |
| Fungi | 3.36 a | 3.21 b | 0.016 | 3.45 a | 3.35 b | 3.26 c | 3.09 d | 0.023 | <0.01 | <0.01 | 0.31 | <0.01 | 0.14 |
| Total bacteria | 9.82 b | 9.93 a | 0.035 | 9.78 b | 9.83 b | 9.86 b | 10.04 a | 0.049 | <0.01 | <0.01 | <0.01 | <0.01 | 0.04 |
a,b,c,d Values in a line within the same class without a common superscript are significantly different (p < 0.05). 1 HF, high-forage substrate; LF, low-forage substrate. 2 SEM, standard error of the difference of the means.3 I, interaction effect; L, linear; Q, quadratic.