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Selection for predicted carcass lean content in Scottish Blackface sheep

Published online by Cambridge University Press:  02 September 2010

S. C. Bishop
S. C. Bishop
Affiliation:
AFRC Roslin Institute (Edinburgh)†, Midlothian EH25 9PS
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Abstract

Scottish Blackface sheep have been selected for either increased or decreased predicted carcass lean content at 20 weeks of age, using an index combining ultrasonic backfat depth and body weight. The index was designed to alter carcass lean content without changing body weight. After 4 years there have been large responses in the index and fat depth, the proportional difference between the divergent lines in fat depth is 0·28, but body weight and ultrasonic muscle depth have not changed between the lines. The realized heritability for the index is 0·45. Heritabilities for the index, ultrasonic fat depth, body weight and ultrasonic muscle depth, calculated using multivariate restricted maximum likelihood, are 0·47 (s.e. = 0·14), 0·39 (s.e. 0·13), 0·23 (s.e. 0·12) and 0·36 (s.e. 0·14), respectively. The selected lines will be used to investigate relationships between carcass lean content, viability and maternal performance under the harsh environmental conditions encountered in the Scottish hill environment.

Keywords

genetic parametersselectionsheepultrasonic backfat

Information

Type
Research Article
Information
Animal Production , Volume 56 , Issue 3 , June 1993, pp. 379 - 386
Copyright
Copyright © British Society of Animal Science 1993

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References

Atkins, K. D. 1986. A genetic analysis of the components of lifetime productivity in Scottish Blackface sheep. Animal Production 43: 405–419.Google Scholar
Atkins, K. D. and Thompson, R. 1986. Predicted and realized responses to selection for an index of bone length and body weight in Scottish Blackface sheep. 1. Responses in the index and component traits. Animal Production 43: 421–435.Google Scholar
Bennett, G. L. 1990. Selection for growth and carcass composition in sheep. Proceedings of the fourth world congress on genetics applied to livestock production, Vol. 15, pp 27–37.Google Scholar
Bennett, G. L., Meyer, H. H. and Kirton, A. H. 1988. Effects of selection for divergent ultrasonic fat depth in rams on progeny fatness. Animal Production 47: 379–386.Google Scholar
Cameron, N. D. and Bracken, J. 1992. Selection for carcass lean content in a terminal sire breed of sheep. Animal Production 54: 367–377.Google Scholar
Cunningham, J. M. M. and Groves, C. R. 1985. The hills and uplands of the UK. In Hill and upland livestock production (ed. Maxwell, T. J. and Gunn, R. G.) occasional publication, no. 10, British Society of Animal Production, pp. 1–8.Google Scholar
Kadim, I. T., Purchas, R. W., Rae, A. L. and Barton, R. A. 1989. Carcass characteristics of Southdown rams from high and low backfat selection lines. New Zealand Journal of Agricultural Research 32: 181–191.CrossRefGoogle Scholar
Lawes Agricultural Trust. 1983. GENSAT a general statistical program. Numerical Algorithms Group Limited.Google Scholar
McEwan, J. C., Fennessy, P. F., Bain, W. E. and Greer, G. R. 1990. Selection for leanness in sheep. Proceedings of the fifth Australasian Association of Animal Production conference, Taipei, Taiwan, Vol. 3, p. 252.Google Scholar
Meyer, K. 1985. Maximum likelihood estimation of variance components for a multivariate mixed model with equal design matrices. Biometrics 41: 153–165.CrossRefGoogle ScholarPubMed
Mrode, R. A., Smith, C. and Thompson, R. 1990. Selection for rate and efficiency of lean gain in Hereford cattle. 1. Selection pressure applied and direct responses. Animal Production 51: 23–34.Google Scholar
Newman, J. A., Rahnefeld, G. W. and Fredeen, H. T. 1973. Selection intensity and response to selection for yearling weight in beef cattle. Canadian Journal of Animal Science 53: 1–12.CrossRefGoogle Scholar
Pattie, W. A. 1965. Selection for weaning weight in Merino sheep. 1. Direct response to selection. Australian Journal of Experimental Agriculture and Animal Husbandry 5: 353–360.CrossRefGoogle Scholar
Russel, A. J. F., Gunn, R. G. and Doney, J. M. 1968. Components of weight loss in pregnant hill ewes during winter. Animal Production 10: 43–51.CrossRefGoogle Scholar
Thompson, R. and Juga, J. 1989. Cumulative selection differentials and realized heritabilities. Animal Production 49: 203–208.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: 1–7.Google Scholar
Wolf, B. T., Smith, C. and Sales, D. I. 1980. Growth and carcass composition in the crossbred progeny of six terminal sire breeds of sheep. Animal Production 31: 307–313.Google Scholar
Young, M. A. 1989. Responses to selection for leanness in Suffolk sheep. M.Sc. thesis, University of Edinburgh.Google Scholar