Hostname: page-component-76fb5796d-dfsvx Total loading time: 0 Render date: 2024-04-26T19:55:18.506Z Has data issue: false hasContentIssue false
  • English
  • Français

A genetic analysis of early growth and ultrasonic measurements in hill sheep

Published online by Cambridge University Press:  02 September 2010

J. Conington ,
S. C. Bishop ,
A. Waterhouse  and
G. Simm
J. Conington
Affiliation:
Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG
S. C. Bishop
Affiliation:
Roslin Institute(Edinburgh), Roslin, Midlothian EH25 9PS
A. Waterhouse
Affiliation:
Scottish Agricultural College, Auchincruive, Ayr KA6 5HW
G. Simm
Affiliation:
Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG
Get access

Abstract

Genetic parameters were estimated for early lamb growth and ultrasonic measurements taken on Scottish Blackface lambs reared under extensive conditions on two Scottish hill farms. Measurements were taken on approximately 2000 lambs born to unselected ewes, and sired by 32 rams previously selected for divergent predicted carcass lean content. Heritabilities for birth weight, marking iveight (at approx. 6 weeks of age) and weaning weight (at 17 weeks) were 0·07 (s.e. 0·04), 0·02 (s.e. 0·03), and 0·14 (s.e. 0·05), respectively. Heritabilities for ultrasonic muscle and fat depths at weaning were 0·27 (s.e. 0·09) and 0·16 (s.e. 0·06), respectively. There was a strong maternal effect on weight which declined from birth with lamb age and was relatively unimportant for the ultrasonic measurements. The rearing environment of the lambs (hill pasture v. ‘improved’ (or ‘inbye’) pasture) was an important environmental effect on the heritability estimate for backfat thickness, with that for lambs reared on improved pasture being twice that of hill-reared lambs. The implications of the results from this work on genetic improvement of sheep in liill environments are discussed.

Keywords

environmental factorsgenetic parameterssheepultrasonic measurements
Type
Research Article
Information
Animal Science , Volume 61 , Issue 1 , August 1995 , pp. 85 - 93
Copyright
Copyright © British Society of Animal Science 1995

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. 1984. The estimation of responses to selection in hill sheep. Ph.D. thesis, University of Edinburgh.Google Scholar
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
Barillet, F., Bibe, B. and Bouix, J. 1982. Genetic parameters of the growth 0-150 d within 2 standardised breeding environments for Lacaune shee p breed. Proceedings of the second world congress on genetics applied to livestock production vol. 8, pp.712–731.Google Scholar
Bennett, G. L. 1990. Selection of 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
Bioux, J., Bibé, B. and Lefevre, C. 1982. Genetic parameters of growth and carcass quality for meat sheep in progeny testing station. Proceedings of the second world congress on genetics applied to livestock production, vol. 8, pp.732–738.Google Scholar
Bishop, S. C. 1993. Selection for predicted carcass lean content in Scottish Blackface sheep. Animal Production 56:379–386.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
Fennessy, P. F., Bain, W. E., Greer, G. J. and Johnstone, P. D. 1992. Carcass characteristics of progeny from ram lambs selected for high or low ultrasonic backfat thickness. New Zealand Journal of Agricultural Research 35:177–183.Google Scholar
Henningsson, T. and Malmfors, G. 1992. Liveweight of Swedish lambs at 120 days of age and its correlations with carcass traits. Proceedings of the forty-third annual meeting of the European Association for Animal Production, Madrid, paper SV.5.Google Scholar
Lawes Agricultural Trust. 1983. Genstat, a general statistical program. Numerical Algorithms Group Limited.Google Scholar
Maria, G. A., Boldman, K. G., Van Vleck, L. D. 1993. Estimates of variances due to direct and maternal effects for growth traits of Romanov sheep, journal of Animal Science 71:845–849.Google Scholar
Mavrogenis, A. P., Louca, A. and Robinson, O. W. 1980. Estimates of genetic parameter s for pre-weaning and post-weaning growth traits in Chios lambs. Animal Production 30:271–276.Google Scholar
Meat and Livestock Commission. 1988. Sheep in Britain. Sheep Improvement Services, Milton Keynes.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
Simm, G. 1992. Selection for lean meat production in sheep. In Progress in sheep and goat research (ed. Speedy, A. W.), pp. 193–215. CAB International, Wallingford.Google Scholar
Simm, G., Dingwall, W. S., Murphy, S. V. and FitzSimons, J. 1990. Selection for improved carcass composition in Suffolk sheep. Proceedings of the fourth world congress on genetics applied to livestock production, vol. 15, pp.100–103.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
Waldron, D. F., Clarke, J. N., Rae, A. L., Kirton, A. H. and Bennett, G. L. 1992. Genetic and phenotypic parameter estimates for selection to improve lamb carcass traits. New Zealand journal of Agricultural Research 35:287–298.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
Young, M. J. and Simm, G. 1990. Genetic parameters for in vivo body measurernents in Suffolk sheep. Proceedings of the New Zealand Society of Animal Production 50:403–406.Google Scholar