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Submitted to: Journal of Dairy Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/3/1994
Publication Date: N/A
Citation: Interpretive Summary: The feeding of live microorganisms, probiotics, has a potential market value of $200 million for cattle in the U.S. This assumes that probiotics are as effective as ionophores (monensin) in increasing animal production. However, of the cattle studies reported, only 50% indicate that probiotics increase production efficiency. The objective of our studies was to determine if the inconsistent response with probiotics is due to a limiting dose of the probiotic being fed. Therefore, besides the recommended dose of 3 g/cow per day, we also fed 9 and 27 g to determine if the fungal probiotic, Aspergillus oryzae, has a positive or negative effect on digestion of low quality bromegrass (6% crude protein). Results from six cows fed each level indicated that the probiotic had no effect on digestion in the rumen with the exception that the total volatile fatty acids were higher when 27 g daily were fed. These results indicate that feeding higher levels than the recommended dose of this probiotic do not produce inhibitory consequences; however, feeding higher levels also does not guarantee a stimulatory effect or increased production efficiency.
Technical Abstract: The objective of this study was to determine if Aspergillus oryzae fermentation extract (Amaferm) produced a stimulatory effect or any inhibitory responses on ruminal fermentation when fed at higher levels than the recommended dose of 3 g daily. Using an incomplete Latin square design, four dietary treatments of 0, 3, 9, and 27 g Amaferm were fed daily to six cows fitted with ruminal cannula. For each of four periods, bromegrass hay (6% CP) with and without Amaferm was fed for 28 d; 1 to 14 d for adaptation, 15 to 21 d for feed intake and 22 to 28 d for ruminal sampling. Dacron bags containing bromegrass cell walls were ruminally incubated to determine ruminal fiber degradation at 3, 6, 9, 12, 24, 48, and 72 h. Amaferm did not affect degradation of cell walls, cellulose or hemicellulose. Total ruminal anaerobic or cellulolytic bacteria were not different between treatments; neither were the proportions of cellulolytic species, Butyrivibrio sp., Ruminococcus albus or R. flavefaciens. Ruminal ammonia was not different; however, total VFA was higher and pH tended to be lower when 27 g daily were fed. The proportion of VFA was not different between treatments. These results indicate that Amaferm fed at nine times the recommended dosage did not produce any stimulatory effects, with the exception of total VFA; and it was not inhibitory or toxic to ruminal metabolism and forage fiber degradation.