Influence of feeding Aspergillus oryzae fermentation extract (Amaferm) on in situ fiber degradation, ruminal fermentation, and microbial protein synthesis in nonlactating cows fed alfalfa or bromegrass hay.

Daily additions of 3 g of Amaferm to alfalfa (13% CP) and bromegrass (6% CP) diets were evaluated for effects on ruminal and postruminal fiber and organic matter digestion, fermentation profile, and duodenal bacterial nitrogen flow. Eight beef cows were fitted with ruminal and duodenal cannulas. Two experiments were conducted. Eight cows were fed bromegrass hay, four received Amaferm and four served as controls; later, seven cows received alfalfa hay with three receiving Amaferm and four serving as controls. Each experiment lasted 28 d: d 1 to 14 for adaptation, d 15 to 21 for measurement of feed intake, and d 22 to 28 for ruminal and duodenal sampling. Dacron bags containing NDF substrate from alfalfa or bromegrass were used to determine ruminal fiber degradation at 3, 6, 9, 12, 24, 48, and 72 h. There were no Amaferm effects (P > .15) on rate or extent of fiber degradation in situ when bromegrass of alfalfa was fed. There were no Amaferm effects (P > .10) on concentrations or molar proportions of ruminal VFA, pH, or NH3 or on feed intake in either experiment. There were no effects (P > .10) of Amaferm on site or extent of organic matter or fiber digestion, or duodenal nitrogen flow in cows fed either bromegrass or alfalfa. Amaferm increased (P < .10) the number of ruminal anaerobic bacteria in cows fed bromegrass but not in those fed alfalfa.(ABSTRACT TRUNCATED AT 250 WORDS)