Dry matter intake, rumen fermentation and microbial nitrogen supply in pelibuey sheep fed low-quality rations and different levels of corn oil

Résumé 0

"Eight Pelibuey hair sheep (45 ±2.2kg body weight), cannulatedin the rumen and kept in metabolic stalls in a roofed building,were used to determine the effect of the incorporation of corn oilin a concentrate upon dry matter (DM) intake, rumen fermentationof DM, organic matter (OM) crude protein (CP) and neutraldetergent fiber (NDF), as well as microbial N supply to thesmall intestine. Sheep were fed low-quality Guinea hay (Panicummaximum) grass ad libitum and 300g daily of a commercial concentrateto which 0, 4, 8 and 12% of corn oil was added. VoluntaryDM intake was measured and rumen fermentation of DM,OM, CP and NDF neutral detergent fiber were estimated with thenylon bag technique, after hay incubation in the rumen for 6, 12,24, 48, 72 and 96h. Urinary excretion of purine derivatives wasdetermined. As oil concentration was increased, DM intake of haydecreased (P0.05) between treatments, but rates of digestion (fraction c)were higher for DM, OM and CP when oil was not included inthe supplement (4.9, 14.5 and 10.4%/h, respectively). Digestionrate of NDF was higher (5.71%/h; P0.05) between treatments; however, addition of 8%oil decreased (5.11 ±0.29 gd) microbial N supply with respect to4% (6.18 ±0.29), and N supply was lower when the oil was notadded (4.73 ±0.27) than when it was added at 4, 8 and 12%(6.18 ±0.29, 5.11 ±0.29 and 5.19 ±0.29, respectively). Corn oilin the concentrate fed to sheep tended to decrease DM intake oflow-quality tropical hay without effects on rumen degradabilityand microbial N supply to the small intestine."