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Comparison of theoretical and simulated equilibrium genetic response rates with progeny testing in dairy cattle

Published online by Cambridge University Press:  02 September 2010

Karin Meyer  and
C. Smith
Karin Meyer
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

The published theoretical estimates of equilibrium genetic change possible by progeny testing in dairy cattle are too high. Much of the overestimation is because no account has been taken of the temporary reduction in genetic variation due to selection of parents and ancestors. A particular efficient progeny testing scheme was modelled theoretically and simulated on computer using a continuous infinitesimal additive model. To make the simulation feasible an elite breeding herd of females was used, and progeny testing was done outside the herd. The proportional reduction in genetic variance due to previous selection was 0·25, 0·27 and 0·29 for original heritabilities of 0·05, 0·25 and 0·50, with the theoretical and simulated results being very similar. The theoretical and simulated proportional losses in equilibrium selection responses were 0·22 and 0·26, 0·21 and 0·22 and 0·21 and 0·25, respectively, for the three levels of heritability. Thus, most of the loss in response in the simulation results came from the reduction in genetic variance due to selection.

Keywords

dairy cattlegenetic varianceprogeny testingselection responses
Type
Research Article
Information
Animal Production , Volume 50 , Issue 2 , April 1990 , pp. 207 - 212
Copyright
Copyright © British Society of Animal Science 1990

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References

REFERENCES

Bulmer, M. G. 1971. The effect of selection on genetic variability. American Naturalist 105: 201–211.CrossRefGoogle Scholar
Falconer, D. S. 1981. Introduction to Quantitative Genetics. 2nd ed. Longmans, London.Google Scholar
Fimland, E. 1979. The effect of selection on additive genetic parameters. Zeitschrift für Tierzuchtung und Züchtungsbiologie 96: 120–134.CrossRefGoogle Scholar
Gomez-Raya, L. and Burnside, E. B. 1989. Linkage disequilibrium effects on genetic variance, heritability and response after repeated cycles of selection. Theoretical and Applied Genetics. In press.Google Scholar
Hill, W. G. 1977. Order statistics of correlated variables and implications in genetic selection programmes. II. Response to selection. Biometrics 33: 703–712.CrossRefGoogle Scholar
Juga, J. and Maki-Tanila, A. 1987. Genetic change in nucleus breeding dairy herds using embryo transfer. Ada Agriculturae Scandinavica 37: 511–519.CrossRefGoogle Scholar
Nicholas, F. W. and Smith, C. 1983. Increased rates of genetic change in dairy cattle by embryo transfer and splitting. Animal Production 36: 341–353.Google Scholar
Robertson, A. 1961. Inbreeding in artificial selection programmes. Genetical Research 2: 189–194.CrossRefGoogle Scholar
Robertson, A. and Rendel, J. M. 1950. The use of progeny testing with artificial insemination in dairy cattle. Journal of Genetics 50: 21–31.CrossRefGoogle ScholarPubMed
Van Vleck, L. D. 1986. Evaluation of dairy cattle breeding programs: specialized milk production. Proceedings of the 3rd World Congress on Genetics Applied to Livestock Production, Vol. 9, pp. 141–152.Google Scholar
Van Vleck, L. D. 1988. Observations on selection advances in dairy cattle. Proceedings of 2nd International Conference on Quantitative Genetics (ed. Weir, B. S., Eisen, E. J., Goodman, M. M. and Namkoong, G.), pp. 433–437.Google Scholar
Woolliams, J. A. 1989. Modifications to MOET nucleus breeding schemes to improve rates of genetic progress and decrease rates of inbreeding in dairy cattle. Animal Production 49: 1–14.Google Scholar
Woolliams, J. A. and Smith, C. 1988. The value of indicator traits in the genetic improvement of dairy cattle. Animal Production 46: 333–345.CrossRefGoogle Scholar