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Metabolism of the lactating cow: III. Properties of mechanistic models suitable for evaluation of energetic relationships and factors involved in the partition of nutrients

Published online by Cambridge University Press:  01 June 2009

R. Lee Baldwin ,
James France ,
David E. Beever ,
Margaret Gill  and
John H. M. Thornley
R. Lee Baldwin
Affiliation:
Department of Animal Science, University of California, Davis CA 95616USA
James France
Affiliation:
Animal and Grassland Research Institute, Hurley, Maidenhead SL6 5LR, UK
David E. Beever
Affiliation:
Animal and Grassland Research Institute, Hurley, Maidenhead SL6 5LR, UK
Margaret Gill
Affiliation:
Animal and Grassland Research Institute, Hurley, Maidenhead SL6 5LR, UK
John H. M. Thornley
Affiliation:
Animal and Grassland Research Institute, Hurley, Maidenhead SL6 5LR, UK
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Summary

TWO models of lactating dairy cows were constructed by combining mechanistic models of digestion and metabolism reported previously and by adding elements to allow simulation of changes in tissue metabolic capacities over time. One model (day version) had an integration interval of 0·005 d and was suitable for simulation of within-day dynamics of nutrient supply and partition. The other (lactation version) had an integration interval of 1 d and was suitable for simulation of full lactation cycles. A number of simulation analyses were conducted to characterize and evaluate the models, to examine quantitative and dynamic properties of mechanisms which influence partition of nutrients, to identify aspects requiring further study, and to illustrate the potential usefulness of mechanistic, as compared to empirical, models in analyses of energy balance in lactating dairy cows.

Type
Original Articles
Information
Journal of Dairy Research , Volume 54 , Issue 1 , February 1987 , pp. 133 - 145
Copyright
Copyright © Proprietors of Journal of Dairy Research 1987

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References

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