02972naa a2200301 a 450000100080000000500110000800800410001902400850006010000190014524501770016426000090034152020350035065000110238565000150239665000100241165000120242165000160243365000100244965300310245965300180249070000170250870000160252570000160254170000200255770000170257770000160259477300600261015177262026-01-15       1997    bl uuuu     u00u1 u    #d7 ahttps://doi-org.ez103.periodicos.capes.gov.br/10.1016/S0921-4488(96)00981-92DOI1 aGOETSCH, A. L.  aNet flux of nutrients across splanchnic tissues in wethers consuming bermudagrass or ryegrass-wheat hay supplemented with rumen undegradable protein.h[electronic resource]  c1997  aAbstract: Crossbred wethers (14, 37 ± 1.5 kg BW and 10 months old) were used in a 21-day experiment (2 × 2 factorial) to determine effects of dietary grass source (tropical vs temperate) on response to rumen undegradable protein supplementation in oxygen consumption by, and net flux of N fractions across, the portal-drained viscera and liver. Bermudagrass (B; 73.1% NDF and 6.2% CP) or ryegrass-wheat (RW; 65.9% NDF and 8.9% CP) hay was supplemented with 53 g day−1 (DM) of soybean meal (S) or 53 g day−1 (DM) of soybean meal plus 70 g day−1 (DM) of a mixture of feedstuffs high in rumen undegradable protein (SR; 46.6% com gluten, 26.7% feather and 26.7% blood meals). Digestible energy intake (9.1, 10.0, 11.3 and 12.1 MJ day−1) was greater (P &lt 0.01) for RW than for B, and N intake was 12.5, 21.5, 16.5 and 25.3 g day−1 (SE 1.08) for B-S, B-SR, RW-S and RW-SR, respectively. Splanchnic energy use as a percentage of DE intake was less (P = 0.03) for RW vs B (21.4 vs 27.8%). Supplementation with Sr increased (P = 0.04) alpha-amino N release by the portal-drained viscera (6.6, 22.0, 9.8 and 20.6 mmol h−1) and hepatic uptake (10.9, 25.6, 11.2 and 14.3 mmol h−1 for B-S, B-SR, RW-S and RW-SR, respectively; SE 2.29). Supplementation with Sr increased (P &lt 0.01) hepatic urea N release (26.7, 48.4, 29.0 and 41.8 mmol h−1) and ammonia N uptake (17.3, 29.7, 23.3 and 26.6 mmol h−1 for B-S, B-SR, RW-S and RW-SR, respectively) more (interaction; P = 0.09 and 0.08, respectively) with B than with RW. In conclusion, these results indicate that DE intake and splanchnic energy consumption for tropical and temperate grasses may influence metabolic fate of rumen undegradable protein N and, thus, impact potential performance benefits of supplementation. Also, unless forage intake is changed, any improvements in animal performance with rumen undegradable protein supplementation would be through increased N absorption without change in energy available to peripheral tissues, regardless of grass source.  aForage  aMetabolism  aSheep  aConsumo  aMetabolismo  aOvino  aRumen undegradable protein  aSuplementacao1 aPATIL, A. R.1 aWANG, Z. S.1 aPARK, K. K.1 aGALLOWAY, D. L.1 aROSSI, J. E.1 aKOUAKOU, B.  tSmall Ruminant Researchgv. 25, n. 2, p. 119-128, 1997.