Ammonia requirements for rumen fermentation. (Abstract)

Abstract

9A AMMONIA REQUIREMENTS FOR RUMEN FERMENTATION F. ALVAREZ*, R. M. DIXON* and T. R. PRESTON* The minimum concentration of rumen digestion by the microorganisms has been (Satter and Roffler, 1977) or 235 mg N/l experiment the NH3-N requirements for DM in sheep given fibre-based diets. NH30N for estimated (Mehrez & digestion maximal rate to be SO-100 &. 1977) . were measured of mg In in rmen N/l this vivo Five rumen-fistulated sheep (25-35 kg) were given &f &&m freshly chopped pen&&WI PuhputreWn forage alone ('Expt 2)) or this forage and containing 93% NaOH (5%) treated maize 450. g/d of a supplement (Expt 1) c&s, 5%. molasses and 2% -minerals (Control) or incorporating 2% urea (Urea A), 4% urea (Urea H) or 21.6% soyabean meal (Soya). Rumen fluid was sampled 6 times during the experimental day to measure pH and NH.30N concentration, and duplicate nylon bags containing ground NaOH (5%) treated,maize cobs or dried and ground mature b&Wb?~ ~WLPWL~W~ forage were incubated in the rumen for 9 h and 24 h. TABLE I Intake and rumen digestion with forage plus N supplements Rumen concentration of NH3N was increased with supplements containing urea or soy&&an meal. The nylon bag m digestion of both feedstuffs was increased by supplements. containing urea or soyabean meal. The results suggest that the mir&num ammonia concentration for maximum fermentation of mature PGLkWiZti PWLweWn forage was between 32 and 90 mg NH3-N/l, but for NaOH treated ma&e cobs was fn excess of 133 mg N/l. MEHREZ, A. 2.) @?SKOV, E. R. and McDONALD, I. (3977). &L J. Nutr. SATTER, L. D. and ROFFLLER, R. R. 447, 38: C (1977) 0 Trap, Anim. Prod. 2: - 248. - * Institute de Produc&& Animal, Facultad de Agronda, Universidad Central de Venezuela, Maracay, Venezuela.