Table 2.
Rumen fermentative parameters of Angus heifers according to RFI groups.
| Itemsa | HRFI | LRFI | SEMb | P-valuec |
|---|---|---|---|---|
| pH | 6.63 | 6.86 | 0.09 | 0.10 |
| NH3-N, mg/dl | 10.40 | 11.07 | 0.98 | 0.64 |
| TVFA, mM | 58.89 | 62.09 | 4.64 | 0.64 |
| VFAs, molar % of TVFA | ||||
| Acetate | 71.35 | 70.99 | 0.22 | 0.33 |
| Propionate | 16.04 | 16.41 | 0.40 | 0.54 |
| Butyrate | 9.77 | 9.68 | 0.19 | 0.77 |
| Valerate | 0.55 | 0.60 | 0.02 | 0.12 |
| Isobutyrate | 0.99 | 0.93 | 0.13 | 0.73 |
| Isovalerate | 1.30 | 1.39 | 0.13 | 0.64 |
| AP | 4.47 | 4.34 | 0.11 | 0.44 |
a
HRFI, high residual feed intake; LRFI, low residual feed intake; VFAs, volatile fatty acids; TVFAs, total VFAs; AP, the acetate-to-propionate ratio.
b
SEM, standard error of the mean.
c
P-values were derived using a Student's t-test to assess the differences between the HRFI and LRFI groups.