Table 5.
Effect of grape pomace powder (GPP), mangosteen peel powder (MPP) and monensin on nitrogen balance, excretion of urinary purine derivatives (PD) and microbial crude protein supply in dairy steers
| Items | Control | Monensin | GPP | MPP | SEM |
|---|---|---|---|---|---|
| N balance (g/d) | |||||
| N intake | 62.6 | 64.1 | 65.9 | 65.0 | 1.37 |
| Fecal N | 14.2 | 13.8 | 14.1 | 14.0 | 0.27 |
| Urinary N | 20.3 | 19.1 | 19.4 | 18.8 | 0.98 |
| N absorption | 48.4 | 50.3 | 51.8 | 51.0 | 2.11 |
| N retention | 28.1a | 31.2ab | 32.4b | 32.2b | 1.69 |
| PD (mmol/d) | |||||
| Allantoin excretion | 77.3a | 82.2ab | 88.4b | 86.8b | 2.79 |
| Allantoin absorption | 66.4a | 72.3ab | 79.8b | 77.8b | 3.22 |
| MNS (g/d) | 48.3a | 52.6ab | 58.0b | 56.5ab | 2.34 |
| MCP (g/d) | 301.6a | 328.4ab | 362.6b | 353.4ab | 14.65 |
| EMNS (g N/kg OMDR) | 21.0a | 23.4b | 23.5b | 22.4ab | 0.80 |
SEM, standard error of the means; MNS, microbial nitrogen supply; MCP, microbial crude protein; EMNS, efficiency of microbial nitrogen synthesis; OMDR, digestible OM apparently fermented in the rumen.
ab
Values in the same row with different superscripts differ (p<0.05).