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Selection indices for terminal sires to improve lean meat production from sheep in the United Kingdom

Published online by Cambridge University Press:  02 September 2010

A. C. Parratt
Affiliation:
Edinburgh School of Agriculture, West Mains Road, Edinburgh EH9 3JG
G. Simm
Affiliation:
Edinburgh School of Agriculture, West Mains Road, Edinburgh EH9 3JG
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Abstract

Selection indices to improve lean meat production of terminal sire breeds of sheep were derived. An aggregate breeding value which comprised growth rate, killing-out proportion and carcass lean proportion was examined. Selection criteria included growth rate and ultrasonic or X-ray computer tomography (CT) estimates of carcass composition. Correlations betwen the index and the aggregate breeding value were about 0·38 for indices using ultrasonic fat measurements, and about 0·40 for those using CT measurements. Dropping ultrasonic or CT measurements from the indices reduced the correlations with the aggregate breeding value by only about 0·01 and 002 respectively, indicating that selection on growth rate alone under current economic conditions was highly efficient. Changes in economic weights, and genetic parameters had little effect on the efficiency of selection. The total national discounted value of returns from a single round of selection on the indices was expected to be between £6 and £30·5 million, depending on penetration rates of improved stock, the breeding scheme used, and with a time horizon of 20 years.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1987

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References

Bennett, G. L. and Clarke, J. N. 1984. Expected selection responses in lamb carcass composition and weight. Proceedings of the New Zealand Society of Animal Production 44: 243247.Google Scholar
Botkin, M. P., Field, R. A., Riley, M. L., Nolan, J. C. and Roehrkasse, G. P. 1969. Heritability of carcass traits in lambs. Journal of Animal Science 29: 251255.Google Scholar
Brascamp, E. W., Smith, C. and Guy, D. R. 1985. Derivation of economic weights from profit equations. Animal Production 40: 175179.Google Scholar
Cunningham, E. P. 1970. Selind: A Fortran computer program for genetic selection indices. An Foras Taluntais. Dunsinea, Castleknock, Co. Dublin, Eire. (Mimeograph).Google Scholar
Fowler, V. R., Bichard, M. and Pease, A. 1976. Objectives in pig breeding. Animal Production 23: 365387.Google Scholar
Hight, G. K. and Jury, K. E. 1970. Hill country sheep production. II. Lamb mortality and birth weights in Romney and Border Leicester x Romney flocks. New Zealand Journal of Agricultural Research 13: 735752.Google Scholar
Hinch, G. M., Crosbie, S. F., Kelly, R. W., Owens, J. L. and Davis, G. H. 1985. Influence of birth weight and litter size on lamb survival in high fecundity Booroola-Merino crossbred flocks. New Zealand Journal of Agricultural Research 28: 3138.Google Scholar
James, J. W. 1982. Economic aspects of developing breeding objectives: general considerations. In Future Developments in the Genetic Improvement of Animals (ed. Barker, J. S. F., Hammond, K. and McClintock, A. E.), pp. 107118, Academic Press, Sydney.Google Scholar
Kempster, A. J., Cook, G. L. and Grantley-Smith, M. 1986. National estimates of body composition of British cattle, sheep and pigs with special reference to trends in fatness: a review. Meat Science 17: 107138.Google Scholar
Kendall, M. G. and Stuart, S. 1958. The Advanced Theory of Statistics. Vol. I. Griffin, London.Google Scholar
Meat and Livestock Commission. 1984. Sheep Yearbook. Meat and Livestock Commission, Bletchley.Google Scholar
Moav, R. 1973. Economic evaluation of genetic differences. In Agricultural Genetics (ed. Moav, R.), pp. 319352. Wiley, New York.Google Scholar
Nute, G. R., Francombe, M. A. and Dransfield, E. 1983. Consumer attitudes to fatness in meat. Proceedings of the 5th Home Economics Research Conference, Cardiff.Google Scholar
Scottish Agricultural Colleges. 1984. Farm Management Handbook 1984/85. Publication No. 144.Google Scholar
Sehested, E. 1984. Evaluation of carcass composition of live lambs based on computed tomography. Proceedings of the 35th Meeting of the European Association of Animal Production, The Hague.Google Scholar
Simm, G., Smith, C. and Prescott, J. H. D. 1986. Selection indices to improve the efficiency of lean meat production in cattle. Animal Production 42: 183193.Google Scholar
Smith, C. 1978. The effect of inflation and form of investment on the estimated value of genetic improvement in farm livestock. Animal Production 26: 101110.Google Scholar
Smith, C. 1986. Use of embryo transfer in genetic improvement of sheep. Animal Production 42: 8188.Google Scholar
Smith, G. M. 1977. Factors affecting birth weight, dystocia and preweaning survival in sheep. Journal of Animal Science 44: 745753.Google Scholar
Smith, J. F. 1985. Immunisation of ewes against steroids: A review. Proceedings of the New Zealand Society of Animal Production 45: 171177.Google Scholar
Tess, M. W., Benne'it, G. L. and Dickerson, G. E. 1983. Simulation of genetic changes in life cycle efficiency of pork production. II. Effects of components on efficiency. Journal of Animal Science 56: 354368.Google Scholar
Webster, A. J. F. 1977. Selection for leaness and the energetic efficiency of growth in meat animals. Proceedings of the Nutrition Society 36: 5359.Google Scholar
Wolf, B. T., Smith, C., King, J. W. B. and Nicholson, D. 1981. Genetic parameters of growth and carcass composition in crossbred lambs. Animal Production 32: 17.Google Scholar