Microbial protein supply from the rumen

This paper considers the theory, assessment and prediction of microbial pro tein synthesis in the rumen. The difficulties of techniques for assessing m icrobial protein synthesis, as well as the complexity of the rumen ecosyste m, have limited progress. Inconsistencies in the literature undermine the v alue of incorporating advanced rumen models into rationing schemes and limi t the exploitation of microbial protein as an important protein resource fo r ruminants. The paper gives examples of situations in which particular fac tors have significant effects on microbial protein synthesis, but moves on to discuss the development of new less-invasive approaches for estimating m icrobial protein synthesis. The latter approaches have the attraction of of fering in-built technology transfer through the development of diagnostic t ests, based on samples of milk or urine. Some of these techniques offer a d escription of rumen function that is less rigorously quantitative (in terms of microbial protein synthesis), but more usefully qualitative (in terms o f microbial populations, substrates and interactions). (C) 2000 Elsevier Sc ience B.V. All rights reserved.