Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-30T14:35:03.560Z Has data issue: false hasContentIssue false

Combining clonal response and genetic response in dairy cattle improvement

Published online by Cambridge University Press:  02 September 2010

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
Get access

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
Copyright
Copyright © British Society of Animal Science 1989

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

Hulle, L. R. and Van Vleck, L. D. 1984. Cloning embryos as a method of genetic improvement. Genetics Research 1983/1984, Report to the Eastern Artificial Insemination Cooperative Inc., USA.Google Scholar
Marx, J. L. 1988. Cloning sheep and cattle embryos. Science, Washington 239: 463464.Google ScholarPubMed
Nicholas, F. W. and Smith, C. 1983. Increased rates of genetic change in dairy cattle by embryo transfer and splitting. Animal Production 36: 341353.Google Scholar
Smith, C. 1989. Cloning and genetic improvement of beef cattle. Animal Production 49: 4962.Google Scholar
Van Vleck, L. D. 1981. Potential genetic impact of artificial insemination, sex selection, embryo transfer, cloning and selfing in dairy cattle. In New Technologies in Animal Breeding (ed. Brackett, B. G., Seidel, G. E. and Seidel, S. M.), pp. 221242. Academic Press, New York.Google Scholar
Woolliams, J. A. 1989. The value of cloning in MOET nucleus breeding schemes for dairy cattle. Animal Production 48: 3135.CrossRefGoogle Scholar
Woolliams, J. A. and Smith, C. 1988. The value of indicator traits in the genetic improvement of dairy cattle. Animal Production 46: 333345.Google Scholar