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A model of the energy system of lactating and pregnant cows

Published online by Cambridge University Press:  02 September 2010

J. M. Bruce
Affiliation:
Scottish Farm Buildings Investigation Unit, Craibstone, Bucksburn, Aberdeen, AB2 9TR
P. J. Broadbent
Affiliation:
Scottish Farm Buildings Investigation Unit, Craibstone, Bucksburn, Aberdeen, AB2 9TR
J. H. Topps
Affiliation:
North of Scotland College of Agriculture, 581 King Street, Aberdeen AB9 1UD
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Abstract

1. A deterministic model and computer program of the energy system of lactating and pregnant cows have been developed.

2. Input data for cow, nutritional, management and environmental factors are required.

3. The output of milk production, live weight and heat production is a time series, with a weekly time-step.

4. Suckler and dairy cow examples are given to illustrate the use of the model to evaluate the effects of quality, quantity and pattern of food intake, and shelter.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1984

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References

REFERENCES

Agricultural Reseárch Council. 1980. The Nutrient Requirements of Ruminant Livestock. Commonwealth Agricultural Bureaux, Slough.Google Scholar
Blaxter, K. L. and Wainman, F. W. 1961. Environmental temperature and the energy metabolism and heat emission of steers. J. agric. Sci., Camb. 56: 8190.CrossRefGoogle Scholar
Broadbent, P. J., Topps, J. H., Clark, J. J. and Bruce, J. M. 1984. Evaluatio n of a model of the energy system of lactating and pregnant cows. Anim.Prod. 38: 363375.Google Scholar
Brody, S. 1945. Bioenergetics and Growth. Reinhold, New York.Google Scholar
Bruce, J. M. 1980. Modelling the climatic energy demand on suckler cows. Anim. Prod. 30: 449450 (Abstr.).Google Scholar
Bruce, J. M. 1982. The effect of food level and environment on suckler cows. Anim. Prod. 34: 393394 (Abstr.).Google Scholar
Forbes, J. M. 1977. Development of a model of voluntary food intake and energy balance in lactating cows. Anim. Prod. 24: 203214.Google Scholar
Gonzalez-Jimenez, E. and Blaxter, K. L. 1962. The metabolism and thermal regulation of calves in the first month of life. Br. J. Nutr. 16: 199212.CrossRefGoogle Scholar
Holmes, W. 1973. Size of animal in relation to productivity. Nutritional aspects. Proc. Br. Soc. Anim.Prod. (New Ser.) 2: 2734.Google Scholar
Linzell, J. L. 1972. Milk yield, energy loss in milk, and mammary gland weight in different species. Dairy Sci. Abstr. 34: 351360.Google Scholar
Robinson, J. J., McDonald, I., Fraser, C. and Gordon, J. G. 1980. Studies on reproduction in prolific ewes. 6. The efficiency of energy utilization for conceptus growth. J. agric. Sci., Camb. 94: 331338.CrossRefGoogle Scholar
Taylor, St C. S. 1968. Time taken to mature in relation to mature weight for sexes, strains and species of domesticated mammals and birds. Anim. Prod. 10: 157169.Google Scholar
Taylor, St C. S. 1973. Genetic differences in milk production in relation to mature body weight. Proc.Br. Soc. Anim. Prod. (New Ser.) 2: 1526.Google Scholar
Webster, A. J. F. 1974. Heat loss from cattle with particular emphasis on the effects of cold. In Heat Loss from Animals and Man (ed. Monteith, J. L. and Mount, L. E.), pp. 205–231. Butterworth, London.Google Scholar
Wood, P. D. P. 1979. A simple model of lactation curves for milk yield, food requirement and body weight. Anim. Prod. 28: 5563.Google Scholar
Wood, P. D. P. 1980. Breed variations in the shape of the lactation curve of cattle and their implications for efficiency. Anim. Prod. 31: 133141.Google Scholar