Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-24T04:26:14.170Z Has data issue: false hasContentIssue false
  • English
  • Français

Efficiency of energy utilization in cattle given food ad libitum: predictions according to the ARC system and practical consequences

Published online by Cambridge University Press:  02 September 2010

B. J. Tolkamp  and
J. J. M. H. Ketelaars
B. J. Tolkamp
Affiliation:
Department of Tropical Animal Production, Wageningen Agricultural University, PO Box 338, 6700 AH Wageningen, The Netherlands
J. J. M. H. Ketelaars
Affiliation:
Centre for Agrobiological Research, PO Box 14, 6700 AH Wageningen, The Netherlands
Get access

Abstract

Overall efficiency of energy utilization (i.e. total net energy intake as a fraction of metabolizable energy intake) in cattle given food ad libitum was calculated from information included in the United Kingdom energy evaluation system as published by the Agricultural Research Council. For growing cattle (live weight 250 kg), overall efficiency was estimated for five levels of diet metabolizability (ranging from q = 0·45 to q = 0·65) for each of two diet types: coarse/long roughage and fine/pelleted diets. The overall efficiencies varied from 0·58 to 0·62 and were not systematically affected by diet type or diet metabolizability. For lactating cattle (live weight 600 kg), overall efficiency was also calculated for five diets with metabolizability ranging from 0·45 to 0·65. Calculations were made for cows at equilibrium intake (i.e. zero energy balance) and at milk production levels proportionately 0·30 higher or lower than those attained at equilibrium intake. Overall efficiencies varied from 0·60 to 0·63 and were not systematically affected by diet metabolizability.

It is concluded that, in practical cattle production systems with ad libitum feeding, the net energy content of food may be estimated at 0·6 of the metabolizable energy content (or 0·5 of the digestible energy content), irrespective of diet type, diet metabolizability or productive function.

Keywords

cattleenergyfood intakegrowthlactation
Type
Research Article
Information
Animal Production , Volume 59 , Issue 1 , August 1994 , pp. 43 - 47
Copyright
Copyright © British Society of Animal Science 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Agricultural Research Council. 1980. The nutrient requirements of ruminant livestock. Commonwealth Agricultural Bureaux, Farnham Royal.Google Scholar
Ketelaars, J. J. M. H. and Tolkamp, B. J. 1992a. Toward a new theory of feed intake regulation in ruminants. 1. Causes of differences in voluntary feed intake: critique of current views. Livestock Production Science 30: 269–296.CrossRefGoogle Scholar
Ketelaars, J. J. M. H. and Tolkamp, B. J. 1992b. Toward a new theory of feed intake regulation in ruminants. 3. Optimum feed intake: in search of a physiological background. Livestock Production Science 31: 235–258.Google Scholar
Tolkamp, B. J. and Ketelaars, J. J. M. H. 1992. Toward a new theory of feed intake regulation in ruminants. 2. Costs and benefits of feed consumption: an optimization approach. Livestock Production Science 30: 297–317.Google Scholar