Table 1.
Rumen fermentation parameters, body weight, ADWG, fecal N, BUN, and plasma nitrogen fractionation (δ 15N) in pregnant heifers grazing tropical forage at late-dry season, two months on supplementation or un-supplemented.
| Un-Supplemented | Supplemented | SEM | p-Value | |
|---|---|---|---|---|
| Body weight (Kg) | 379 | 437 | 8.17 | 0.002 |
| N intake kg/day | 0.002 | 0.023 | 0.001 | 0.001 |
| Supplement intake kg/day | 0.015 | 0.153 | 0.001 | 0.001 |
| ADWG (Kg) | −0.374 | 0.674 | 0.09 | 0.001 |
| δ 15Nplasma protein | 7.11 | 5.44 | 0.11 | 0.001 |
| Fecal N % | 1.10 | 1.12 | 0.03 | 0.72 |
| Ammonia-N mg/L | 14.3 | 23.9 | 3.17 | 0.15 |
| BUN mg/100 mL | 4.66 | 4.75 | 0.30 | 0.89 |
| Total VFA mM | 75.8 | 75.8 | 3.31 | 0.99 |
| Fatty acid % | ||||
| Acetate | 73.2 | 74.5 | 0.27 | 0.031 |
| Propionate | 18.2 | 14.0 | 0.38 | 0.005 |
| Butyrate | 7.70 | 8.65 | 0.16 | 0.007 |
| iso-Butyrate | 0.25 | 0.34 | 0.03 | 0.084 |
| Valerate | 0.37 | 0.41 | 0.01 | 0.167 |
| iso-Valerate | 0.24 | 0.32 | 0.03 | 0.161 |
| Acetic:Propionic ratio | 4.08 | 4.73 | 0.11 | 0.008 |