Skip to main content Accessibility help
×
Home

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

  • B. J. Tolkamp (a1) and J. J. M. H. Ketelaars (a2)

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.

Copyright

References

Hide All
Agricultural Research Council. 1980. The nutrient requirements of ruminant livestock. Commonwealth Agricultural Bureaux, Farnham Royal.
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: 269296.
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: 235258.
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: 297317.

Keywords

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

  • B. J. Tolkamp (a1) and J. J. M. H. Ketelaars (a2)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed