Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-27T13:14:13.844Z Has data issue: false hasContentIssue false

Efficiency of energy utilisation and voluntary feed intake in ruminants

Published online by Cambridge University Press:  15 March 2010

B. J. Tolkamp*
Affiliation:
Animal Nutrition and Health, SAC, West Mains Road, Edinburgh EH9 3JG, Scotland
Get access

Abstract

Energy requirements of animals are most readily expressed in terms of net energy (NE), while the energy yield of feed is, at least initially, expressed in terms of metabolisable energy (ME). Energy evaluation systems ‘translate’ NE requirements into ME requirements (ME systems) or assign NE values to feeds (NE systems). Efficiency of ME utilisation is higher for maintenance than for production and the NE yield of a feed varies, therefore, with ME intake. In addition, energetic efficiency for maintenance and production is thought to be different for lactating and non-lactating animals and to be affected by diet quality. As a result, there are currently many national energy evaluation systems that are complex, differ in their approach and are, as a result, difficult to compare. As ruminants in most production systems are fed ad libitum, this is also the most appropriate intake level at which to estimate energetic efficiency. Analyses of older as well as more recent data suggest that ad libitum feeding (i) abolishes the effects of diet quality on energetic efficiency (almost) completely, (ii) abolishes the differences between lactating and non-lactating animals (almost) entirely and (iii) results in overall energetic efficiencies that are always close to 0.6. The paper argues that there is now sufficient information to develop an international energy evaluation system for ad libitum fed ruminants. Such a system should (i) unify ME and NE systems, (ii) avoid the systematic bias and large errors that can be associated with current systems (iii) be simpler than current systems and (iv) have as a starting point a constant efficiency of ME utilisation, with a value of around 0.6. The remarkably constant efficiency of ME utilisation in ad libitum fed ruminants could be the result of energetic efficiency as well as feed intake regulation being affected by the same variables or of a direct role of energetic efficiency in feed intake regulation. Models to predict intake on the basis of the latter hypothesis are already available for non-reproducing ruminants but remain to be developed for reproducing animals.

Type
Full Paper
Copyright
Copyright © The Animal Consortium 2010

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

Agnew, RE, Yan, T, France, J, Kebreab, E, Thomas, C 2004. Energy requirement and supply. In Feed into milk. A new applied feeding system for dairy cows (ed. C Thomas), pp. 1120. Nottingham University Press, Nottingham, UK.Google Scholar
Agricultural Research Council 1980. The nutrient requirements of ruminant livestock. CAB International, Wallingford, UK.Google Scholar
Agricultural and Food Research Council 1993. Energy and protein requirements of ruminants. An advisory manual prepared by the AFRC technical committee on responses to nutrients. CAB International, Wallingford, UK.Google Scholar
Bauman, DE, Davis, CL 1974. Biosynthesis of milk fat. In Lactation (ed. BL Larson and VR Smith), vol. II. pp. 3169. Academic Press, New York, USA.Google Scholar
Beever, DE, Cammell, S, Sutton, JD, Rowe, N, Perrott, GE 1998. Energy metabolism in high yielding cows. In Proceedings of the British Society of Animal Science 1998 Annual Meeting. BSAS, Penicuik, UK, p. 13.CrossRefGoogle Scholar
Blaxter, KL 1989. Energy metabolism in animals and man. Cambridge University Press, Cambridge, UK.Google Scholar
Blaxter, KL, Boyne, AW 1978. The estimation of the nutritive value of feeds as energy sources for ruminants and the derivation of feeding systems. Journal of Agricultural Science 90, 4768.CrossRefGoogle Scholar
Commonwealth Scientific and Industrial Research Organisation 1990. Feeding standards for Australian livestock: ruminants. Compiled by the Ruminants Subcommittee of the Standing Committee on Agriculture. CSIRO, East Melbourne, Australia.Google Scholar
Cushnahan, A, Mayne, C, Unsworth, EF 1995. Effects of ensilage of grass on performance and nutrient utilization by dairy cattle. 2. Nutrient metabolism and rumen fermentation. Animal Science 60, 347359.CrossRefGoogle Scholar
Emmans, GC, Kyriazakis, I 1995. Optimisation in animals: uses and dangers. Livestock Production Science 44, 189197.CrossRefGoogle Scholar
Gordon, FJ, Patterson, DC, Yan, T, Porter, MG, Mayne, CS, Unsworth, EF 1995. The influence of genetic index for milk production on the response to complete diet feeding and the utilisation of energy and nitrogen. Animal Science 61, 199210.CrossRefGoogle Scholar
Gordon, FJ, Patterson, DC, Porter, MG, Unsworth, EF 2000. The effect of degree of grass wilting prior to ensiling on performance and energy utilisation by lactating dairy cattle. Livestock Production Science 64, 291294.Google Scholar
Institute National de la Recherche Agronomique 1989. Ruminant nutrition, recommended allowances & feed tables. (ed. R Jarrige). John Libbey and Co Ltd, London.Google Scholar
Kebreab, E, France, J, Agnew, RE, Yan, T, Dhanoa, MS, Dijkstra, J, Beever, DE, Reynolds, CK 2003. Alternatives to linear analysis of energy balance data from lactating cows. Journal of Dairy Science 86, 29042913.CrossRefGoogle Scholar
Ketelaars, JJMH, Tolkamp, BJ 1992. Toward a new theory of feed intake regulation in ruminants. 1. Causes of differences in voluntary intake: critique of current views. Livestock Production Science 30, 269296.CrossRefGoogle Scholar
Ketelaars, JJMH, Tolkamp, BJ 1996. Oxygen efficiency and the control of energy flow in animals and man. Journal of Animal Science 74, 30363051.CrossRefGoogle Scholar
National Research Council 2000. Nutrient requirements of beef cattle, 7th revised edition. National Academy Press, Washington DC, USA.Google Scholar
National Research Council 2001. Nutrient requirements of dairy cattle, 7th revised edition. National Academy Press, Washington DC, USA.Google Scholar
Sutton, JD, Cammell, S, Beever, DE, Humphries, DJ, Phipps, R 1998. Energy and nitrogen balance of lactating dairy cows given mixtures of urea-treated whole-crop wheat and grass silage. Animal Science 67, 203212.Google Scholar
Sutton, JD, Phipps, RH, Cammell, SB, Humphries, DJ 2001. Attempts to improve the utilization of urea-treated whole-crop wheat by lactating dairy cows. Animal Science 73, 137147.CrossRefGoogle Scholar
Thomas, C (ed.) 2004. Feed into milk. A new applied feeding system for dairy cows. Nottingham University Press, Nottingham, UK.Google Scholar
Tolkamp, BJ, Ketelaars, JJMH 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.Google Scholar
Tolkamp, BJ, Ketelaars, JJMH 1994. Efficiency of energy utilisation in cattle given food ad libitum: predictions according to the ARC system and practical consequences. Animal Production 59, 4347.Google Scholar
Tolkamp, BJ, Kyriazakis, I 2009. Toward a new practical energy evaluation system for dairy cows. Animal 3, 307314.CrossRefGoogle Scholar
Tolkamp, BJ, Emmans, GC, Yearsley, J, Kyriazakis, I 2002. Optimisation of short-term animal behaviour and the currency of time. Animal Behaviour 64, 946953.Google Scholar
Tolkamp, B, Emmans, GC, Kyriazakis, I 2006. Body fatness affects feed intake of sheep at a given body weight. Journal of Animal Science 84, 17781789.CrossRefGoogle Scholar
Tolkamp, BJ, Yearsley, JM, Gordon, IJ, Illius, AW, Speakman, JR, Kyriazakis, I 2007. Predicting the effects of body fatness on the intake and performance of sheep. The British Journal of Nutrition 97, 12061215.Google Scholar
Van Es, AJH 1978. Feed evaluation for ruminants. 1. The system in use from May 1977 onwards in the Netherlands. Livestock Production Science 5, 331345.CrossRefGoogle Scholar
Van Es, AJH, Vermorel, M, Bickel, H 1978. Feed evaluation for ruminants – new energy-systems in Netherlands, France and Switzerland – general introduction. Livestock Production Science 5, 327330.CrossRefGoogle Scholar
Vermorel, M 1989. Energy: the feed unit systems. In INRA: ruminant nutrition, recommended allowances & feed tables (ed. R Jarrige). pp. 2332. John Libbey and Co. Ltd, London.Google Scholar
Yan, T, Patterson, DC, Gordon, FJ, Porter, MG 1996. The effects of wilting of grass prior to ensiling on the response to bacterial inoculation. 1. Silage fermentation and nutrient utilization over three harvests. Animal Science 62, 405441.Google Scholar
Yan, T, Gordon, FJ, Agnew, RE, Porter, MG, Patterson, DC 1997. The metabolisable energy requirement for maintenance and the efficiency of utilisation of metabolisable energy for lactation by dairy cows offered grass silage-based diets. Livestock Production Science 51, 141150.Google Scholar