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Dissemination of genetic improvement through a livestock industry

Published online by Cambridge University Press:  02 September 2010

Maurice Bichard
Maurice Bichard
Affiliation:
School of Agriculture, The University, Newcastle upon Tyne, NE1 7RU
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Summary

A theoretical study is reported of the way in which additive genetic improvement, made in a nucleus population, is passed to successive levels in a three-tier multiplication system. The rate at which progress accumulates at each level is approximately equal. The extent to which each tier is genetically behind the previous one has been termed the ‘improvement lag’. These lags can be considerable; their actual size is determined by the annual rate of progress in the nucleus, the age structure in the lower tiers, and by the origins and degree of selection achieved in the animals used as parents in these tiers. Only improvements generated in the top tier are cumulative. The scope for reducing the improvement lag is discussed within the context of livestock production in Britain.

Type
Research Article
Information
Animal Production , Volume 13 , Issue 3 , August 1971 , pp. 401 - 411
Copyright
Copyright © British Society of Animal Science 1971

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References

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