Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-27T21:27:40.579Z Has data issue: false hasContentIssue false
  • English
  • Français

Selection for carcass lean content in a terminal sire breed of sheep

Published online by Cambridge University Press:  02 September 2010

N. D. Cameron  and
J. Bracken
N. D. Cameron
Affiliation:
AFRC Institute of Animal Physiology and Genetics Research, Edinburgh Research Station, Roslin, Midlothian EH25 9PS
J. Bracken
Affiliation:
AFRC Institute of Animal Physiology and Genetics Research, Edinburgh Research Station, Roslin, Midlothian EH25 9PS
Get access

Abstract

A divergent selection experiment for carcass leanness in Texel-Oxford sheep was established to examine the differences between genetically lean and fat animals derived from the same base population. The selection criterion was designed to change body composition without a corresponding change in live weight, using an index of ultrasonic backfat depth and live weight at 20 weeks of age. The index was constructed using estimates of genetic and phenotypic parameters, which were available at the start of the experiment in 1985. The difference between the high and low lines, after 3 years of selection, for the selection index, live weight at 20 weeks of age, ultrasonic backfat and muscle depths was 0·59,1·30 kg, -0·76 mm and 0·88 mm respectively. The estimated difference for carcass lean and fat weight was 0·72 kg and -0·04 kg respectively with 13·5 g/kg and -13·8 g/kg for carcass lean and fat proportion. The realized heritability for the selection index, estimated from the regression of cumulative response on cumulative selection differential was 0·42, with a standard error of 0·25, after taking account of genetic drift. The selection index heritability, estimated with residual maximum likelihood (REML) methodology, was 0·46 (s.e. 0·14). REML heritability estimates for live weight at 20 weeks of age, ultrasonic backfat and muscle depths were 0·20 (s.e. 0·13), 0·35 (s.e. 0·14) and 0·43 (s.e. 0·14) respectively.

Keywords

carcass compositiongenetic parametersselectionsheepultrasonic fat measurement
Type
Research Article
Information
Animal Production , Volume 54 , Issue 3 , June 1992 , pp. 367 - 377
Copyright
Copyright © British Society of Animal Science 1992

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

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 i n the index and component traits. Animal Production 43: 421–435.Google Scholar
Bennett, G. L. 1990. Selection for growth and carcass composition in sheep. Fourth world congress on genetics applied to livestock production, vol. 15, pp. 27–36.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 Drury, D. J. 1985. Comparison of terminal sire breeds for growth and carcass traits in crossbred lambs. Animal Production 40: 315–322.Google Scholar
Falconer, D. S. 1981. Introduction to quantitative genetics. 2nd ed. Longman, London.Google Scholar
Fennessy, P. F., Greer, G. J. and Bass, J. J. 1982. Progeny test of selected lean and fat rams. Proceedings of the New Zealand Society of Animal Production 42: 137–140.Google Scholar
Hill, W. G. 1972. Estimation of realised heritabilities from selection experiments. 1. Divergent selection. Biometrics 28: 747–765.CrossRefGoogle Scholar
James, J. W. 1986. Cumulative selection differentials and realized heritabilities with overlapping generations. Animal Production 42: 411–415.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
Kempster, A. J., Cook, G. L. and Grantley-Smith, M. 1986. National estimates of the body composition of British cattle, sheep and pigs with special reference to trends in fatness: a review. Meat Science 17: 107–138.CrossRefGoogle ScholarPubMed
Lawes Agricultural Trust. 1983. GENSTAT 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 Australian 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
Meyer, K. 1989. Restricted maximum likelihood to estimate variance components for animal models with several random effects using a derivative-free algorithm. Genetique, Selection et Evolution 21: 317–340.CrossRefGoogle Scholar
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
Nute, G. R., Francombe, M. A. and Dransfield, E. 1983. Consumer attitudes to fatness in meat. Proceeding of the fifth home economics research conference.Google Scholar
Parratt, A. C., Burt, C. M., Bennett, G. L., Clarke, J. N., Kirton, A. H. and Rae, A. L. 1987. Heritabilities, genetic and phenotypic correlations for carcass traits and ultrasonic fat depth in sheep. Proceeding of the sixth Australian Association of Animal Breeding and Genetics Conference, pp. 76–78.Google Scholar
Pattie, W. A. 1965. Selection for weaning in Merino sheep. 1. Direct response to selection. Australian Journal of Experimental Agriculture and Animal Husbandry 5: 353–360.CrossRefGoogle Scholar
Quaas, R. L. and Pollak, E. J. 1980. Mixed model methodology for farm and ranch beef cattle testing programs. Journal of Animal Science 51: 1277–1287.CrossRefGoogle Scholar
Sales, J. and Hill, W. G. 1976. Effect of sampling errors on efficiency of selection indices. 2. Use of information on associated traits for improvement of a single important trait. Animal Production 23: 1–14.Google Scholar
Simm, G. 1987. Carcass evaluation in sheep breeding programmes. In New techniques in sheep production (ed. Marai, I. F. and Owen, J. B.), pp. 125–144, Butterworths, London.CrossRefGoogle Scholar
Simm, G. and Dingwall, W. S. 1989. Selection indices for lean meat production in sheep. Livestock Production Science 21: 223–233.CrossRefGoogle Scholar
Simm, G., Dingwall, W. S., Murphy, S. V. and FitzSimons, J. 1990. Selection for improved carcass composition in Sufolk sheep. Fourth world congress on genetics applied livestock production, vol. 15, pp. 100–104.Google Scholar
Simm, G., Young, M. J. and Beatson, P. R. 1987. An economic selection index for lean meat production in New Zealand sheep. Animal Production 45: 465–475.Google Scholar
Smith, S. P. and Graser, H. U. 1986. Estimating variance components in a class of mixed models by restricted maximum likelihood. Journal of Dairy Science 69: 1156–1165.CrossRefGoogle Scholar
Thompson, J. M. 1990. Correlated responses to selection for growth and leanness in sheep. Fourth world congress on genetics applied to livestock production, vol. 16, pp. 266–275Google Scholar
Thompson, R. and Atkins, K. D. 1990. Estimation of heritability from selection experiments. Fourth world congress on genetics applied to livestock production, vol.13, 257–260.Google Scholar
Thompson, R. and Juga, J. 1989. Cumulative selection differentials and realized heritabilities. Animal Production 49: 203–208.Google Scholar
Vangen, O. 1979. Studies on a two trait selection experiment in pigs. II. Genetic changes and realized genetic parameters in the traits under selection. Acta Agriculturae Scandinavica 29: 305–319.CrossRefGoogle Scholar
Van Vleck, D. 1988. Notes on the theory and applications selection principals for the genetic improvement of animals. Cornell University, Ithaca.Google Scholar
Webster, J. F. 1977. Selection for leanness and the energetic efficiency of growth in meat animals. Proceeding of the Nutrition Society 36: 53–59.CrossRefGoogle ScholarPubMed
Whitehead, C. C. 1988. Selection for leanness in broilers using plasma lipoprotein concentration as selection criterion. Leanness in domestic birds (ed. Leclercq, B. and Whitehead, C. C.), pp. 59–70. Butterworths, London.Google Scholar
Williams, D. A. 1982. The use of the deviance to test the goodness of fit of a logistic-linear model to binary data. GLIM Newsletter 6: 60–62.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
Young, M. J. 1989. Responses to selection for leanness in Suffolk sheep. M.Sc. Thesis, University of Edinburgh.Google Scholar