Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-06T01:17:20.850Z Has data issue: false hasContentIssue false
  • English
  • Français

Value of conformation as an indicator of sheep carcass composition within and between breeds

Published online by Cambridge University Press:  02 September 2010

A. J. Kempster ,
D. Croston  and
D. W. Jones
A. J. Kempster
Affiliation:
Meat and Livestock Commission, PO Box 44, Queensway House, Bletchley, Milton Keynes MK2 2EF
D. Croston
Affiliation:
Meat and Livestock Commission, PO Box 44, Queensway House, Bletchley, Milton Keynes MK2 2EF
D. W. Jones
Affiliation:
Meat and Livestock Commission, PO Box 44, Queensway House, Bletchley, Milton Keynes MK2 2EF
Get access

Abstract

Carcass evaluation data from two breed-comparison trials were used to examine the value of conformation as an indicator of carcass composition when used in addition to carcass weight and different measures of fatness. One trial involved 1478 crossbred lambs out of three ewe types by Border Leicester, Dorset Down, Ile-de-France, North Country Cheviot, Oxford Down, Southdown, Suffolk, Texel and Wensleydale sires. The other trial involved 920 crossbred lambs out of two dam types by Dorset Down, Ile-de-France, Oldenburg, Oxford Down, Suffolk and Texel sires. Each trial extended over 3 years.

Conformation contributed little to the prediction of carcass lean percentage or proportion of lean in the higher-priced joints, although the additional precision was often significant at P<0·01. When conformation was used in association with dissected subcutaneous fat percentage, it was positively associated with carcass lean content; used with a visual assessment of external fat cover on a five-point scale, which provided a less effective control of fatness variation, it tended to be negatively related to carcass lean content.

Conformation was slightly more valuable for the prediction of lean to bone ratio and m. longissimus depth. The addition of sire-breed effect to weight and fat class provided an important increase in the precision of prediction of percentage lean in carcass and lean to bone ratio. Texel progeny had higher lean to bone ratios and more lean in the carcass than progeny of other sire breeds, but they did not have sufficiently high conformation scores to clearly identify this advantage.

Type
Research Article
Information
Animal Production , Volume 33 , Issue 1 , August 1981 , pp. 39 - 49
Copyright
Copyright © British Society of Animal Science 1981

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

REFERENCES

Croston, D., Jones, D. W. and Kempster, A. J. 1979. A comparison of the performance and carcass characteristics of lambs by nine sire breeds. Anim. Prod. 28: 456–457 (Abstr.).Google Scholar
Cuthbertson, A., Harrington, G. and Smith, R. J. 1972. Tissue separation—to assess beef and lamb variation. Proc. Br. Soc. Anim. Prod. (New Ser.) 1: 113–122.CrossRefGoogle Scholar
Jackson, T. H. and Mansour, Y. A. 1974. Differences between groups of lamb carcasses chosen for good and poor conformation. Anim. Prod. 19: 93–105.Google Scholar
Kempster, A. J. 1978. Bone growth and development with particular reference to breed differences in carcass shape and lean to bone ratio. In Patterns of Growth and Development in Cattle. Current Topics in Veterinary Medicine, Vol. 2 (ed. Boer, H. De and Martin, J.), pp. 149–166. Nijhoff, The Hague.CrossRefGoogle Scholar
Kempster, A. J. 1979. Variation in the carcass characteristics of commercial British sheep with particular reference to overfatness. Meat Sci. 3: 199–208.CrossRefGoogle ScholarPubMed
Kempster, A. J., Avis, P. R. D., Cuthbertson, A. and Harrington, G. 1976. Prediction of the lean content of lamb carcasses of different breed types. J. agric. Sci., Camb. 86: 23–34.CrossRefGoogle Scholar
Kempster, A. J. and Cuthbertson, A. 1977. A survey of the carcass characteristics of the main types of British lamb. Anim. Prod. 25: 165–179.Google Scholar
Kempster, A. J. and Harrington, G. 1980. The value of ‘fat-corrected’ conformation as an indicator of beef carcass composition within and between breeds. Livest. Prod. Sci. 7: 361–372.CrossRefGoogle Scholar
Kirton, A. H. and Pickering, F. S. 1967. Factors associated with differences in carcass conformation in lamb. N.Z. Jl agric. Res. 10: 183–200.CrossRefGoogle Scholar
Ringkob, T. P., Zobrisky, S. E., Ross, C. V. and Naumann, H. D. 1964. Measurements of muscle and retail cuts of lamb. Res. Bull. Univ. Mo. Coll. Agric, No. 876.Google Scholar
Spurlock, G. M. and Bradford, G. E. 1965. Comparison of systems of lamb carcass evaluation. J. Anim. Sci. 24: 1086–1091.CrossRefGoogle Scholar
Timon, V. M. and Bichard, M. 1965. Quantitative estimates of lamb carcass composition. 3. Carcass measurements and a comparison of the predictive efficiency of sample joint composition, carcass specific gravity determinations and carcass measurements. Anim. Prod. 7: 189–201.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. Anim. Prod. 31: 307–313.Google Scholar