Table 3 Relative abundance (%) of 10 targeted rumen bacteria species and the 16S rRNA gene copy numbers of the total rumen bacterial community in the rumen solids-fraction of the most- (n = 6) and the least- (n = 6) efficient beef cattle on RFI testing for 70 d during the finishing period
Items1 | RFI2 | SE3 | Sex | SE4 | P-value | ||||
|---|---|---|---|---|---|---|---|---|---|
Most-efficient animals | Least-efficient animals | Steers | Heifers | RFI | Sex | RFI × sex | |||
Target bacterial species | |||||||||
 A. lipolytica | 1.80 × 10−4 | 9.00 × 10−5 | 0.27 | 1.20 × 10−4 | 1.30 × 10− 4 | 0.31 | 0.48 | 0.96 | 0.45 |
 B. proteoclasticus | 1.91 × 10−2 | 1.12 × 10− 2 | 0.22 | 1.33 × 10− 2 | 1.60 × 10− 2 | 0.25 | 0.47 | 0.80 | 0.66 |
 E. ruminantium | 9.13 × 10-2a | 4.18 × 10-2b | 0.10 | 9.09 × 10-2a | 4.20 × 10-2b | 0.11 | 0.05 | 0.05 | 0.84 |
 F. succinogenes | 2.90 × 10-4a | 1.00 × 10-4b | 0.13 | 3.00 × 10-4a | 0.90 × 10-4b | 0.14 | 0.03 | 0.02 | 0.79 |
 M. elsdenii | 7.00 × 10-5a | 3.00 × 10-5b | 0.12 | 4.00 × 10−5 | 5.00 × 10−5 | 0.12 | 0.04 | 0.73 | 0.35 |
 P. bryantii | 4.31 × 10−2 | 3.52 × 10−2 | 0.14 | 5.37 × 10−2 | 2.82 × 10− 2 | 0.16 | 0.67 | 0.20 | 0.40 |
 S. ruminantium | 1.25 × 10−1 | 1.17 × 10−1 | 0.08 | 1.21 × 10−1 | 1.20 × 10−1 | 0.09 | 0.80 | 0.97 | 0.95 |
 S. amylolytica | 0.70 × 10-4b | 3.80 × 10-4a | 0.14 | 2.40 × 10−4 | 1.20 × 10−4 | 0.14 | < 0.01 | 0.16 | 0.83 |
 S. bovis | 5.63 × 10−3 | 6.75 × 10−3 | 0.25 | 6.30 × 10− 3 | 6.03 × 10− 3 | 0.29 | 0.83 | 0.96 | 0.48 |
 S. dextrinosolvens | 4.81 × 10−2 | 1.22 × 10−2 | 0.48 | 1.38 × 10− 2 | 4.26 × 10− 2 | 0.56 | 0.41 | 0.49 | 0.28 |
Bacteria density | |||||||||
 The 16S rRNA gene copy numbers (log10)/ng DNA5 | 8.03b | 8.07a | 0.01 | 8.05 | 8.05 | 0.01 | 0.05 | 0.89 | 0.60 |