Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-10T19:58:21.022Z Has data issue: false hasContentIssue false
  • English
  • Français

An integrated, dynamic model of feed hydration anddigestion, and subsequent bacterial mass accumulation in the rumen

Published online by Cambridge University Press:  09 March 2007

Jaap Van Milgen ,
Larry L. Berger  and
Michael R. Murphy
Jaap Van Milgen
Affiliation:
Department of Animal Sciences, University of Illinois, Urbana, Illinois 61801, USA
Larry L. Berger
Affiliation:
Department of Animal Sciences, University of Illinois, Urbana, Illinois 61801, USA
Michael R. Murphy
Affiliation:
Department of Animal Sciences, University of Illinois, Urbana, Illinois 61801, USA
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Hydration of feeds and bacterial attachment to feed particles are thought to play major roles in rumen digestion of fibrous feedstuffs. The objective of the present study was to integrate these phenomena in a mechanistic model that could be used for data analysis. The proposed model was based on the conversion of biomass, where digestion end-products can be used for the synthesis of bacterial mass. Digestion of the potentially digestible fraction and subsequent accumulation of bacterial mass was based on a sequential, three-compartment model. These compartments represented substrate undergoing hydration, digestion, and bacterial mass accumulation. A fraction of the substrate was used for synthesis of bacterial mass. It was assumed that these bacteria associate either temporarily or permanently with the remaining substrate. Dacron bags containing either dry or fully-hydrated lucerne (Medicago sativa), maize (Zea mays) cobs, orchard grass (Dactylis glomeratd), and wheat straw were incubated in the rumen of a steer that was infused continuously with (15NH4)2SO4. The 15N-enrichments of isolated particle-associated bacteria and residue remaining in the bags were used to estimate bacterial attachment. Substrate remaining and microbial mass accumulation were analysed simultaneously. Hydration did not appear to limit digestion. Fractional rate of digestion and appearance of attached bacterial mass was fastest for lucerne. For lucerne, 5 % of the digestion end-products were used for synthesis of bacteria that associated with the substrate, whereas for maize cobs, orchard grass, and wheat straw this was 16, 14, and 19% respectively. Less than 2% of digestion end-products were used for synthesis of bacteria that permanently remained associated with the substrate. Permanent association can occur only with the indigestible fraction, and probably represents bacterial debris. Lysis and/or detachment of bacterial cells was highest for lucerne, and was indicative of the rapid dynamics of lucerne digestion.

Keywords

ModelsBacterial attachmentRumen digestion
Type
Modelling Feed Intake, Digestion and Rumen Bacteria
Information
British Journal of Nutrition , Volume 70 , Issue 2 , September 1993 , pp. 471 - 483
Copyright
Copyright © The Nutrition Society 1993

References

REFERENCES

Akin, D. E. (1986). Chemical and biological structures in plants as related to microbial degradation of forage cell walls. In Controlof Digestion and Metabolism in Ruminants, pp. 139–157 [Milligan, L. P., Grovum, W. L., and Dobson, A., editors]. Englewood Cliffs, NJ: Prentice-Hall.Google Scholar
Baldwin, R. L., Miller, P. S., Freetly, H. C., Hanigan, M. D., Fadel, J., Bowers, M. K. & Calvert, C. C. (1990). Future of tissue level models. In Modelling Digestion and Metabolism in Farm Animals, pp. 345–357 [Robson, A. B., and Poppi, D. P., editors]. Canterbury, New Zealand: Lincoln University.Google Scholar
Bremner, J. M. & Mulvaney, C. S. (1982). Nitrogen - total. In Methods of Soil Analysis, Part 2. Chemical and Microbiological Properties. Agronomy Monographs no. 9, 2nd ed., pp. 595–624 [Page, A. L., editor]. Madison, WI: American Society of Agronomy Inc.Google Scholar
Cecava, M. J., Merchen, N. R., Berger, L. L., Mackie, R. I. & Fahey, G. C. Jr (1991). Effects of dietary energy level and protein source on nutrient digestion and ruminal metabolism in steers. Journal of Animal Science 69, 2230–2243.Google Scholar
Cecava, M. J., Merchen, N. R., Gay, L. C. & Berger, L. L. (1990). Composition of ruminal bacteria harvested from steers as influenced by dietary energy level, feeding frequency, and isolation techniques. Journal of Dairy Science 73, 2480–2488.Google Scholar
Cheng, K.-J., Fay, J. P., Howarth, R. E. & Costerton, J. W. (1980). Sequence of events in the digestion of fresh legume leaves by rumen bacteria. Applied and Environmental Microbiology 40, 613–625.Google Scholar
Cheng, K.-J., McAllister, T. A., Kudo, H., Forsberg, C. W. & Costerton, J. W. (1991). Microbial strategy in feed digestion. In Recent Advances on the Nutrition of Herbivores, pp. 181–187 [Ho, Y. W., Wong, H. K., Abdullah, N. and Tajuddin, Z. A., editors]. Serdang, Malaysia: Malaysian Society of Animal Production.Google Scholar
Czerkawski, J. W. (1986). Degradation of solid feeds in the rumen: spatial distribution of microbial activity and its consequences. In Control of Digestion and Metabolism in Ruminants, pp. 158–172 [Milligan, L. P., Grovum, W. L., and Dobson, A., editors]. Englewood Cliffs, NJ: Prentice-Hall.Google Scholar
Draper, R. N. & Smith, H. (1981). Applied Regression Analysis, 2nd ed. New York, NY: John Wiley & Sons, Inc.Google Scholar
Firkins, J. L., Berger, L. L., Merchen, N. R. & Fahey, G. C. Jr (1986). Effects of forage particle size, level of feed intake and supplemental protein degradability on microbial protein synthesis and site of nutrient digestion in steers. Journal of Animal Science 62, 1081–1094.Google Scholar
France, J., Thornley, J. H. M., Dhanoa, M. S. & Siddons, R. C. (1985). On the mathematics of digesta flow kinetics. Journal of Theoretical Biology 113, 743–758.Google Scholar
Goering, H. K. & Van Soest, P. J. (1975). Forage Fiber Analyses (Apparatus, Reagents, Procedures, and Some Applications). Agriculture Handbook no. 379. Washington, DC: Agricultural Research Service, United States Department of Agriculture.Google Scholar
Hooper, A. P. & Welch, J. G. (1985). Change of functional specific gravity of forage in various solutions. Journal of Dairy Science 68, 1652–1658.Google Scholar
Mulvaney, R. L., Fohringer, C. L., Bojan, V. J., Michlik, M. M. & Herzog, L. F. (1990). A commercial system for automated nitrogen isotope-ratio analysis by the Rittenberg technique. Review of Scientific Instruments 61, 897–903.Google Scholar
Nocek, J. E. & Grant, A. L. (1987). Characterization of in situ nitrogen and fiber digestion and bacterial nitrogen contamination of hay crop forages preserved at different dry matter percentages. Journal of Animal Science 64, 552–564.Google Scholar
Olubobokun, J. A. & Craig, W. M. (1990). Quantity and characteristics of microorganisms associated with ruminal fluid or particles. Journal of Animal Science 68, 3360–3370.Google Scholar
Olubobokun, J. A., Craig, W. M. & Pond, K. R. (1990). Effects of mastication and microbial contamination on ruminal in situ forage disappearance. Journal of Animal Science 68, 3371–3381.Google Scholar
Papageorgakopoulou, H. & Maier, W. M. (1984). A new modeling technique and computer simulation of bacterial growth. Biotechnology and Bioengineering 26, 275–284.CrossRefGoogle ScholarPubMed
Ratkowsky, D. A. (1983). Nonlinear Regression Modeling. New York, NY: Marcel Dekker.Google Scholar
Roger, V., Fonty, G., Komisarczuk-Bony, S. & Gouet, P. (1990). Effects of physicochemical factors on the adhesion to cellulose Avicel of the ruminal bacteria Ruminococcus flavefaciens and Fibrobacter succinogenes subsp. succinogenes. Applied and Environmental Microbiology 56, 3081–3087.Google Scholar
SAS Institute Inc. (1988 a). SAS/STAT™ User's Guide, release 6.03 ed. Cary, NC: SAS Institute Inc.Google Scholar
SAS Institute Inc. (1988 b). SAS/ETS® User's Guide, version 6. Cary, NC: SAS Institute Inc.Google Scholar
Thornley, J. H. M. & France, J. (1984). Role of modeling in animal production research and extension work. In Modeling Ruminant Digestion and Metabofism. Proceeding of the Second International Workshop, pp. 4–9 [Baldwin, R. L. and Bywater, A. C., editors]. Davis, CA: Department of Animal Science, University of California.Google Scholar
Udén, P., Colucci, P. E. & Van Soest, P. J. (1980). Investigation of chromium, cerium, and cobalt as markers in digesta. Rate of passage studies. Journal of the Science of Food and Agriculture 31, 625–632.Google Scholar
Van Milgen, J., Berger, L. L. & Murphy, M. R. (1992). Fractionation of substrate as an intrinsic characteristic of feedstuffs fed to ruminants. Journal of Dairy Science 75, 124–131.Google Scholar
Van Milgen, J., Murphy, M. R. & Berger, L. L. (1991). A compartmental model to analyze ruminal digestion. Journal of Dairy Science 74, 2515–2529.Google Scholar