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Combining clonal response and genetic response in dairy cattle improvement

Published online by Cambridge University Press:  02 September 2010

G. Teepker  and
C. Smith
G. Teepker
Affiliation:
Centre for Genetic Improvement of Livestock, Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
C. Smith
Affiliation:
Centre for Genetic Improvement of Livestock, Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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Abstract

Repeated cloning of bovine embryos by nuclear transfer, producing large clones of monozygous animals, may be possible in the future. Initially, clones could be tested and the best one selected and spread over the commercial population by embryo transfer. Further genetic improvement could be obtained by rebreeding a number of the best clones to produce a new set of clones. However, the testing and selection systems to pick the best clone (for short-term clonal response) and to pick clones with the best breeding values (for long-term genetic response) are different. The objective of this study was to derive a system which achieves both high clonal and high genetic responses. An adult MOET (multiple ovulation and embryo transfer) scheme with 40 breeding males and 40 breeding females per generation (cycle) was used to maintain adequate genetic variation for continued genetic response. For a fixed set of testing facilities and a given family structure initial clonal response is maximized by testing several members per clone. Long-term genetic response is usually greatest when testing one member per clone. Compromises to obtain both high clonal response and high genetic responses were from 95 to 100% efficient.

Type
Papers
Information
Animal Production , Volume 49 , Issue 2 , October 1989 , pp. 163 - 169
Copyright
Copyright © British Society of Animal Science 1989

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References

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