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A non-linear compartmental model to describe forage degradation kinetics during incubation in polyester bads in the rumen

Published online by Cambridge University Press:  09 March 2007

M.S. Dhanoa
Affiliation:
Institute of Grassiand and Environmental Research, Plas Gogerddan, Aberystwyth, Dyfed SY23 3EB
J. France
Affiliation:
Institute of Grassland and Envirounental Research, North Wyke Research Station, Okehampton, Devon EX20 2SB
R. C. Siddons
Affiliation:
Formerly Institute of Grassland and Environmental Research, Hurley, Maidenhead, Berkshire SL6 5LR
S. Lopez
Affiliation:
Department of Animal Production, University of Leon, 24007 Leon, Spain
J.G. Buchanan-Smith
Affiliation:
Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario NIG 2WI, Canada
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Abstract

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A new model for describing forage degradation kinetics during incubation in the rumen using polyester bags is presented. Attention is given to dealing with the problem of deviations from exponential behaviour in the early stages of degradation by devising a function capable of representing exponential or sigmoidal trends. This is achieved by allowing part of the fractional degradation rate to vary with time of incubation, thus enabling responses other than those expected under simple first-order kinetics to be described. Seven sets of data consisting of 620 curves were analysed to study the performance of the new model compared with a commonly used exponential model. The proportion of significantly better fits varied from set to set. The new model deals successfully with sigmoidal behaviour and, thus, provides a means of analysing the degradation profiles of low-quality

Type
Model for forage degradation kinetics
Copyright
Copyright © The Nutrition Society 1995

References

REFERENCES

Broderick, G. A. (1978) In vitro procedures for estimating rates of ruminal protein degradation and proportions of protein escaping the rumen undegraded. Journal of Nutrition 108, 181190.CrossRefGoogle ScholarPubMed
Beever, D. E., Dhanoa, M. S., Losada, H. R., Evans, R. T., Cammell, S. B. & France, J. (1986) The effect of forage species and stage of harvest on the processes of digestion occurring in the rumen of cattle. British Journal of Nutrition 56, 439454.CrossRefGoogle ScholarPubMed
Bibby, J. & Toutenberg, H. (1977) Prediction and Improved Estimation in Linear Models. London: John Wiley & Sons. Dhanoa, M. S. (1988). On the analysis of dacron bag data for low degradability feeds. Grass and Forage Science 43, 441444.Google Scholar
Dong, Y. (1990) The significance of chewing during eating and rumination on forage digestion in cattle. MSc Thesis, University of Guelph.Google Scholar
France, J., Dhanoa, M. S., Siddons, R. C., Thornley, J. H. M. & Poppi, D. P. (1988) Estimating the production of faeces by ruminants from faecal marker concentration curve. Journal of Theoretical Biology 135, 383391.CrossRefGoogle 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, 743758.CrossRefGoogle ScholarPubMed
France, J., Thornley, J. H. M., Lopez, S., Siddons, R. C., Dhanoa, M. S., Van Soest, P. J. & Gill, M. (1990) On the two compartment model for estimating the rate and extent of feed degradation in the rumen. Journal of Theoretical Biology 146, 269287.CrossRefGoogle ScholarPubMed
Harbers, L. H., Brazle, F. K., Raiten, D. J. & Owensby, C. E. (1981) Microbial degradation of smooth brome and tall fescue observed by scanning electron microscopy. Journal of Animal Science 51, 439446.CrossRefGoogle Scholar
Hartley, R. D. & Dhanoa, M. S. (1981) Rates of degradation of plant cell walls measured with a commercial cellulase preparation. Journal of Science of Food and Agriculture 32, 849856.CrossRefGoogle Scholar
Lopez, S., Carro, M. D., Gonzalez, J. S. & Ovejero, F. J. (1991 a) Rumen degradation of the main forage species harvested from permanent mountain meadows in North-western Spain. Journal of Agricultural Science, Cambridge 117, 363369.CrossRefGoogle Scholar
Lopez, S., Carro, M. D., Gonzalez, J. S. & Ovejero, F. J. (1991 b) The effect of method of forage conservation and harvest season on the degradation of forages harvested from permanent mountain meadows. Animal Production 53, 177182.Google Scholar
McDonald, I. (1981) A revised model for the estimation of protein degradability in the rumen. Journal of Agricultural Science, Cambridge 96, 251252.CrossRefGoogle Scholar
Mertens, D. R. (1973) Application of mathematical models to cell wall digestion and forage intake in ruminants, PhD Thesis, Cornell University.Google Scholar
Ørskov, E. R. & McDonald, I. (1979) The estimation of protein degradability in the rumen from incubation measurements weighted according to rates of passage. Journal of Agricultural Science, Cambridge 92, 449503.CrossRefGoogle Scholar
Ross, G. J. S. (1987) MLP, Maximum Likelihood Program, version 3·08. Oxford: Numerical Algorithms Group.Google Scholar
Schoemdn, E. A., De Vet, P. J. & Burger, W. J. (1972) The evaluation of the digestibility of treated proteins. Agroanimalia 4, 3546.Google Scholar
Siddons, R. C., Paradine, J., Beever, D. E. & Cornell, P. R. (1985 a) Ytterbium acetate as a particulate-phase digesta flow marker. British Journal of Nutrition 54, 509519.CrossRefGoogle ScholarPubMed
Siddons, R. C., Paradine, J., Gale, D. L. & Evans, R. T. (1985 b) Estimation of the degradability of dietary protein in the sheep rumen by in vivo and in vitro procedures. British Journal of Nutrition 54, 545561.CrossRefGoogle ScholarPubMed
Van Keuren, R. W. & Heinemann, W. W. (1962) Study of a nylon bag technique for in vivo estimation of forage digestibility. Journal of Animal Science 21, 340345.CrossRefGoogle Scholar