Submitted to: Quantitative Aspects of Ruminant Digestion and Metabolism
Publication Type: Book / Chapter
Publication Acceptance Date: 9/25/2002
Publication Date: 11/15/2005
Citation: Russell, J.B., Strobel, H.J. 2005. Microbial energetics. In: Dikstra, J., Forbes, J. M., France, J., Editors. Quantitative Aspects of Ruminant Digestion and Metabolism. Wallingford, United Kingdom:CABI Publishing. p. 229-262. Interpretive Summary:
Technical Abstract: Rumen fermentation is an exergonic process that converts feedstuffs to short chain volatile fatty acids, methane, ammonia, and occasionally lactic acid. Some of the free energy is used to drive microbial growth, but heat is also evolved. The efficiency of rumen microbial growth can have a profound effect on animal performance. Microbial protein is a important amino acid supply for the animal, and it is now apparent that the yield of microbial protein can vary significantly. There are innumerable combinations of reactions leading to the formation of cell material, and this complexity is reflected in the diversity of the rumen microbial population. Since feeds are highly heterogeneous, and it appears that no single organism can be ideally fitted to all of the available niches. This complexity has thwarted the ability of nutritionists to estimate the availability of nutrients from dietary ingredients. However, rumen microbiologists and nutritionists are beginning design models that are abl to predict microbial growth in the rumen. New molecular tools and bio-informatics offer the promise for an even better understanding of this ecologically complex environment.