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The CAMDA sheep breeding scheme: II. Genetic progress over twenty years

Published online by Cambridge University Press:  20 November 2017

A. A. Aslaminejad
Affiliation:
Department of Agriculture, University of Aberdeen, Aberdeen, AB24 5UA, UK
R. M. Lewis
Affiliation:
Animal Biology Division, SAC, King's Buildings, Edinburgh EH9 3JG, UK
J. A. Roden
Affiliation:
Department of Agriculture, University of Aberdeen, Aberdeen, AB24 5UA, UK
V.R. Fowler
Affiliation:
Department of Agriculture, University of Aberdeen, Aberdeen, AB24 5UA, UK
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Extract

Two aspects of the CAMDA group breeding scheme is to improve lamb growth rate and the mothering ability of Welsh Mountain sheep. Genetic variation for these traits is present (Aslaminejad et al., 1999) but the rate of genetic progress depends on the selection decisions made within the scheme. The objective of this study was to estimate the genetic gain achieved in the nucleus and members’ flocks over the 20 years since the scheme began.

A total of 31887 records of 12 and 18-week live weight of Welsh Mountain lambs collected between 1976 and 1995 in 7 flocks of the CAMDA scheme were used in this study. Each flock was analysed separately fitting a univariate animal model with a direct and maternal random genetic effect. Genetic parameters were estimated using a derivative-free restricted maximum likelihood algorithm (DFREML; Meyer, 1993).

Type
Programme
Copyright
Copyright © The British Society of Animal Science 1999

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References

Aslaminejad, A.A., Lewis, R.M., Roden, J.A. and Fowler, V.R. 1999. The CAMDA sheep breeding scheme: I. Estimation of genetic parameters for 18-week weight. Proceedings BSAS Annual meeting, Scarborough CrossRefGoogle Scholar
Meyer, K. 1993. DFREML user note. University of New England, Armidale, Australia.Google Scholar
Pollott, G.E., Croston, D. and Guy, D.R. 1994. Genetic progress in the CAMDA group breeding scheme. Animal Science 58:431A.Google Scholar