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The effect of ad lib feeding on the efficiency of energy utilization in growing and lactating cattle

Published online by Cambridge University Press:  24 November 2017

B.J. Tolkamp
Affiliation:
Department of Tropical Animal Production, Wageningen A.U. P.O. Box 338, 6700 AH Wageningen, The Netherlands
J.J.M.H. Ketelaars
Affiliation:
Centre for Agrobiological ResearchP.O. Box 14, 6700 AH Wageningen, The Netherlands
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Extract

Recently, we have proposed a new theory of feed intake regulation in ruminants (Ketelaars and Tolkamp, 1992a,b; Tolkamp and Ketelaars, 1992). This theory attributes great significance to the efficiency of metabolizable energy (ME) utilization for feed intake regulation. In brief, we assume that feed intake behaviour of ruminants aims at maximizing the ratio of net energy intake (representing the benefits of feeding) relative to oxygen consumption (representing the metabolic costs of feeding). Starting from this assumption, we have shown that knowledge of the efficiency of ME utilization obtained under conditions of restricted feeding can be used successfully to predict voluntary intake (Tolkamp and Ketelaars, 1992).

If, indeed, voluntary feed intake and the efficiency of ME utilization are so intimately related, the question comes up what the effect of ad lib feeding is on the overall efficiency of ME utilization (total net energy intake, NEI, as a fraction of ME intake, MEI). This paper investigates this question by means of model calculations for growing and lactating cattle according to the UK energy evaluation system.

Type
Ruminant Metabolism
Copyright
Copyright © The British Society of Animal Production 1993

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References

ARC (Agricultural Research Council), 1980. The nutrient requirements of ruminant livestock. Commonwealth Agricultural Bureaux, Farnham Royal, 351 pp.Google Scholar
Ketelaars, J.J.M.H. and Tolkamp, B.J., 1992a. Livest. Prod. Sci.,30: 269296.CrossRefGoogle Scholar
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