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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

REFERENCES

Baldwin, R. L. & Black, J. L. 1979 Simulation of the effects of nutritional and physiological status on the growth of mammalian tissues: Description and evaluation of a computer program. Melbourne: CSIRO. (Animal Research Laboratories Technical Paper No. 6)Google Scholar
Baldwin, R. L., France, J. & Gill, M. 1987 a Metabolism of the lactating cow. I. Animal elements of a mechanistic model. Journal of Dairy Research 54 77–105CrossRefGoogle ScholarPubMed
Baldwin, R. L., Thornley, J. H. M. & Bbever, D. E. 1987 a Metabolism of the lactating cow. II. Digestive elements of a mechanistic model. Journal of Dairy Research 54 107–131CrossRefGoogle ScholarPubMed
Broster, W. H. & Broster, V. J. 1984 Reviews of the progress of dairy science: Long-term effects of plane of nutrition on the performance of the dairy cow. Journal of Dairy Research 51 149–196CrossRefGoogle ScholarPubMed
Broster, W. H. & Thomas, C. 1981 The influence of level and pattern of concentrate input on milk output. In Recent Advances in Animal Nutrition – 1981 pp. 49–69 (Ed. Haresign, W.). London: ButterworthsCrossRefGoogle Scholar
Flatt, W. P., Moe, P. W., Munson, A. W. & Cooper, T. 1969 Energy utilization by high producing dairy cows. II. Summary of energy balance experiments with lactating Holstein cows. In Energy Metabolism of Farm Animals (Symposium 4, 1967) pp. 235–251 (Eds Blaxter, K. L., Kielanowski, J. and Torbek, G.), Newcastle upon Tyne: Oriel Press (EAAP Publication no. 12)Google Scholar
Leng, R. A. (1970). Formation and production of volatile fatty acids in the rumen. In Physiology of Digestion and Metabolism in the Ruminant (International symposium no. 3, 1969) pp. 406–421 (Ed. Phillipson, A. T.), Newcastle upon Tyne: Oriel PressGoogle Scholar
Neal, H. D. St. C. & Thornley, J. H. M. 1983 The lactation curve in cattle: a mathematical model of the mammary gland. Journal of Agricultural Science 101 389–400CrossRefGoogle Scholar
Romero, J. J., Cañas, R., Baldwin, R. L. & Koong, L.J. 1976 Lactational efficiency complex of rats: provisional model for interpretation of energy balance data. Journal of Dairy Science 59 57–67CrossRefGoogle ScholarPubMed
Smith, N. E. 1970 Modelling studies of ruminant metabolism. Ph.D. thesis, University of California, Davis.Google Scholar
Sutton, J. D. 1985 Digestion and absorption of energy substrates in the lactating cow. Journal of Dairy Science 68 3376–3393CrossRefGoogle Scholar