Energy Nutrition of Rumen Micro-Organisms

  • M. Ryle
  • E. R. Ørskov

Abstract

The rumen has often been compared to a fermentation vat. However, although its temperature and anaerobic state are stable and its pH fluctuations are limited, nothing else is reminiscent of industrial conditions. Both the chemical composition and the physical structure of the ingested substrates can vary widely and rapidly. Instead of one or two types of micro-organism providing the enzymes for fermentation, there may be significant numbers of many species belonging to each of three main groups — bacteria, fungi and protozoa. The relative numbers of the different species vary with the composition and structure of the feed and their mutual interactions are highly complex. Yet although the proportions of the different end-products also vary, they nevertheless normally consist principally of carbon dioxide, methane and the three volatile fatty acids (VFAs) acetic acid, propionic acid and butyric acid, together with ammonia, traces of some other VFAs and sometimes lactic acid.

Keywords

Volatile Fatty Acid Soluble Carbohydrate Rumen Fluid Cellulolytic Bacterium Ciliate Protozoan 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Abe, M., Iriki, T., Tobe, N. & Shibui, H. (1981) Sequestration of Holotrich protozoa in the retículo-rumen of cattle Appi. Env. Microbiol. 41, 758–765Google Scholar
  2. Brock, F.M., Forsberg, C.W. & Buchanan-Smith, J.G. (1982) Proteolytic activity of rumen microorganisms and effects of proteinase inhibitors Appi. Env. Microbiol. 44, 561–569Google Scholar
  3. Coleman, G.S. (1979) The role of rumen protozoa in the metabolism of ruminants given tropical feeds Trop. Anim. Prod. 4, 199–213Google Scholar
  4. Coleman, G.S. (1980) Rumen ciliate protozoa Adv. Parasitol. 18, 121–173CrossRefGoogle Scholar
  5. Coleman, G.S. (1985a) The cellulase content of 15 species of entodiniomorphid protozoa, mixed bacteria and plant debris isolated from the ovine rumen J. agrie. Sci., Camb. 104, 349–360CrossRefGoogle Scholar
  6. Coleman, G.S. (1985b) Possible causes of the high death rate of ciliate protozoa in the rumen J. agrie. Sci., Camb. 105, 39–43CrossRefGoogle Scholar
  7. Coleman, G.S. (1986a) The distribution of carboxymethyl-cellulase between fractions taken from the rumens of sheep containing no protozoa or one of five different protozoal populations J. agrie. Sci., Camb. 106, 121–127CrossRefGoogle Scholar
  8. Coleman, G.S. (1986b) The amylase activity of 14 species of entodiniomorphid protozoa and the distribution of amylase in rumen digesta fractions of sheep containing no protozoa or one of seven different protozoal populations J. agrie. Sci., Camb. 107, 709–721CrossRefGoogle Scholar
  9. Cottle, D.J., Nolan, J.V. & Leng, R.A. (1984) Turnover of protozoa and bacteria in the rumen of sheep Proc. Austr. Soc. Anim. Prod. 12, 138Google Scholar
  10. Demeyer, D.I. (1981) Rumen microbes and digestion of plant cell walls Agric. & Env. 6, 295–337CrossRefGoogle Scholar
  11. Eadie, J.M. (1962) Inter-relationships between certain rumen ciliate protozoa J. gen. Microbiol. 29, 579–588Google Scholar
  12. Ffoulkes, D. & Leng, R.A. (1984) Dynamics of protozoa in the rumen of cattle Anim. Prod, in Austr. 15, 679Google Scholar
  13. Hungate, R.E. (1966) The Rumen and its Microbes Academic Press, New YorkGoogle Scholar
  14. Mountfort, D.O. (1987) The rumen anaerobic fungi FEMS Microbiol. Rev. 46, 401–408Google Scholar
  15. Nugent, J.H. & Mangan, J.L. (1981) Characteristics of the rumen proteolysis of Fraction I (18S) leaf protein from lucerne (Medicago sativa L.) Brit. J. Nutr. 46, 39–58CrossRefGoogle Scholar
  16. Ørskov, E.R., Flatt, W.P. & Moe, P.W. (1968) Fermentation balance approach to estimate extent of fermentation and efficiency of volatile fatty acid formation in ruminants J. Dairy Sci. 51, 1429–1435CrossRefGoogle Scholar
  17. Orpin, C.G. (1984) The role of ciliate protozoa and fungi in the rumen digestion of plant cell walls Anim. Feed Sci. Technol. 10, 121–144Google Scholar
  18. Orpin, C.G. (1985) Association of rumen ciliate populations with plant particles in vitro. Mier ob. Ecol. 11, 59–70Google Scholar
  19. Ryle, M. & 0rskov, E.R. (1987) Rumen ciliates and tropical feeds World Anim. Rev. 64, 21–30Google Scholar
  20. Veira, D.M. (1986) The role of ciliate protozoa in nutrition of the ruminant J. Anim. Sci. 63, 1547–1560Google Scholar
  21. Williams, A.G. (1982) The metabolism and significance of ciliate protozoa in the rumen ecosystem Rep. Hannah Res. Inst. pp. 93–110Google Scholar
  22. Williams, A.G. (1986) Rumen holotrich ciliate protozoa Microbiol. Rev. 50, 25–49Google Scholar
  23. Williams, A.G. & Coleman, G.S. (1985) Hemicellulose-degrading enzymes in ciliate protozoa Curr. Microbiol. 12, 85–90CrossRefGoogle Scholar
  24. Williams, A.G. & Strachan, N.H. (1984) The distribution of polysaccharide- degrading enzymes in the bovine rumen digesta ecosystem Curr. Microbiol. 10, 215–220CrossRefGoogle Scholar
  25. Williams, A.G., Withers, S.E. & Coleman, G.S. (1984) Glycoside hydrolases of rumen bacteria and protozoa Curr. Microbiol. 10, 287–294CrossRefGoogle Scholar
  26. Wolin, M J. (1979) The rumen fermentation: a model for microbial interactions in anaerobic ecosystems Adv. Microb. Ecol. 3, 49–77Google Scholar
  27. Yoder, R.D., Trenkle, A. & Burroughs, W. (1966) Influence of rumen protozoa and bacteria upon cellulose digestion in vitro. J. Anim. Sci. 25, 609–612Google Scholar

Copyright information

© Elsevier Science Publishers Ltd 1990

Authors and Affiliations

  • M. Ryle
    • 1
  • E. R. Ørskov
    • 2
  1. 1.Stocksbridge, SheffieldUK
  2. 2.Applied Research DepartmentThe Rowett Research InstituteUK

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