Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-30T19:33:10.751Z Has data issue: false hasContentIssue false

A comparison of carcass traits in Scottish Blackface and Welsh Mountain lambs and their crosses

Published online by Cambridge University Press:  02 September 2010

G. J. Lee
Affiliation:
AFRC Animal Breeding Research Organisation, West Mains Road, Edinburgh EH9 3JQ
Get access

Abstract

A total of 219 lambs of the Welsh Mountain (W) and Scottish Blackface (B) breeds, and six types of crossbred with varying proportions of the two breeds from a cyclical crossbreeding experiment, were slaughtered in six groups at fortnightly intervals from 6 to 8 months of age. Each group had balanced numbers of each genotype and each sex. Genotype differences and effects of heterosis were estimated. Fat grades were assessed by farm staff before slaughter and Meat and Livestock Commission fat and conformation scores and external linear hindquarter measurements of each carcass were recorded.

At the same age, W carcasses were lighter (W: B = 0·86, W = 11·7 kg, B = 13·4 kg) but were more mature and had more kidney fat (W: B = 1·73) and higher fat and conformation scores especially in the loin region, but relatively shorter, thinner legs. At the same degree of maturity (carcass weight/estimated mature carcass weight), the Welsh carcasses had more kidney fat but the difference in leg measurements was reduced, and the differences for fat and conformation scores disappeared. When compared at the same grade, the Welsh lambs were 2 kg lighter and had higher conformation scores suggesting comparative undergrading, especially by the farm assessors. Results for crossbred lambs were as predicted from their breed composition and there was no evidence of heterosis.

The results suggest that at the same estimated carcass fatness, the Blackface has the potential to produce a heavier carcass but is later maturing, taking approx. 12 days longer to reach this degree of fatness.

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

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

Butterfield, R. M., Zamora, J., James, A. M., Thompson, J. M. and Reddacliff, K. J. 1983a. Changes in body composition relative to weight and maturity in large and small strains of Australian Merino rams. 3. Body organs. Anim. Prod. 36: 461470.Google Scholar
Butterfield, R. M., Zamora, J., James, A. M., Thompson, J. M. and Williams, Jean. 1983b. Changes in body composition relative to weight and maturity in large and small strains of Australian Merino rams. 2. Individual muscles and muscle groups. Anim. Prod. 36: 165174.Google Scholar
Callow, E. H. 1961. Comparative studies of meat. VII. A comparison between Hereford, Dairy Shorthorn and Friesian steers on four levels of nutrition. J. agric. Sci, Camb. 56: 265282.CrossRefGoogle Scholar
Kempster, A. J. 1979. Variation in the carcass characteristics of commercial British sheep with particular reference to overfatness. Meat Sci. 3: 199208.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: 2334.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: 165179.Google Scholar
Kempster, A. J., Cuthbertson, A. and Jones, D. W. 1977. Bone weight distribution in steer carcasses of different breeds and crosses; and the prediction of carcass bone content from the bone content of joints. J. agric. Sci., Camb. 89: 675682.CrossRefGoogle Scholar
McClelland, T. H., Bonaiti, B. and Taylor, St C. S. 1976. Breed differences in body composition of equally mature sheep. Anim. Prod. 23: 281293.Google Scholar
McClelland, T. H. and Russel, A. J. F. 1972. The distribution of body fat in Scottish Blackface and Finnish Landrace lambs. Anim. Prod. 15: 301306.Google Scholar
Purser, A. F. 1981. The performance of Welsh Mountain and Scottish Blackface sheep in a Welsh hill environment. Rep. Anim. Breed. Res, Org., pp. 36.Google Scholar
Truscott, T. G., Lang, C. P. and Tulloh, N. M. 1976. A comparison of body composition and tissue distribution of Friesian and Angus steers. J. agric. Sci., Camb. 87: 114.CrossRefGoogle Scholar
Wiener, G. and Hayter, Susan. 1974. Body size and conformation in sheep from birth to maturity as affected by breed, crossbreeding, maternal and other factors. Anim. Prod. 19: 4765.Google Scholar
Wood, J. D., MacFie, H. J. H., Pomeroy, R. W. and Twinn, D. J. 1980. Carcass composition in four sheep breeds: the importance of type of breed and stage of maturity. Anim. Prod. 30: 135152.Google Scholar