Table 5.
Effects of dietary treatment on allantoin excretion, purine derivative excretion, purine derivative absorption and microbial protein synthesis
| Items | Levels of MUP (g/hd/d) | SEM | |||
|---|---|---|---|---|---|
|
| |||||
| T1 | T2 | T3 | T4 | ||
| Allanoin excretion (mmol/d) | 54.3a | 92.1b | 110.7c | 137.7d | 3.25 |
| PD excretion (mmol/d)1 | 63.9a | 108.4b | 130.3c | 162.0d | 3.82 |
| PD absorption (mmol/d)2 | 59.0a | 111.3b | 137.3c | 174.4d | 4.68 |
| MNS (g N/d)3 | 42.9a | 80.9b | 99.8c | 126.8d | 3.40 |
| MP (g/d)4 | 268.2a | 505.4b | 623.6c | 792.2d | 15.05 |
| EMNS (g N/d of OMDR)5 | 12.6a | 22.7b | 26.1c | 31.0d | 0.90 |
a,b,c
Means in the same row with different superscripts differ (p<0.05).
1
Urinary purine derivative contained allanoin 80–85%.
2
Calculated from (PD excretion-0.147×BW0.75)/0.85.
3
MNS = Microbial nitrogen supply, calculated form (PD absorption×0.727) (Chen and Gomes, 1995).
4
MP = Microbial protein production, calculated from (MNS×6.25).
5
EMNS = Efficiency of microbial nitrogen supply (EMNS, of g/kg of OM digested in the rumen (OMDR) = ((MCP (g/d)×1,000)/DOMR (g)) assuming that rumen digestion = 65% of digestion in total tract.