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Gene flow and potential selection response in age-structured subpopulations having a common male pool

Published online by Cambridge University Press:  18 August 2016

L. Rönnegård  and
Ö. Danell
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Abstract

In extensive pastoral systems, where mating cannot be controlled, the breeding strategies of intermingling owner flocks interact. We present a method to evaluate a breeding programme in extensive reindeer (Rangifer tarandus) management which can also be applied to other pastoral production systems. Our main objective was to evaluate the method by applying sensitivity analyses. The method included a gene flow model with maternal effects. The potential response Rp was defined as the response that could be achieved in a closed nucleus with a given selection procedure. The value of Rp was derived from the gene flow from dams to daughters, selection differentials, and the realized difference between subpopulations. We studied a population structure having two subpopulations, only one of which had been subjected to selection. Random mating between subpopulations and a common male pool were assumed. A reference case was defined using reindeer data from the literature. After 9 years of continued selection among progeny the estimate of Rp was 7·0 times higher than the realized subpopulation difference. We analysed deviations of Rp from the reference case caused by different female age structures between subpopulations. We also analysed the sensitivity of maternal effects. The method proved insensitive to differences in female age structure between subpopulations but was sensitive to the relative contribution of maternal effects to progeny performance.

Keywords

genetic gain, maternal effectsprojectionsrandombred populationsreindeer
Type
Breeding and genetics
Information
Animal Science , Volume 72 , Issue 3 , June 2001 , pp. 427 - 440
Copyright
Copyright © British Society of Animal Science 2001

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References

Bijma, P. and Woolliams, J. A. 1999. Prediction of genetic contributions and generation intervals in populations with overlapping generations under selection. Genetics 151: 1197–1210.Google Scholar
Bijma, P. and Woolliams, J. A. 2000. On the relation between gene flow theory and genetic gain. Genetics, Selection, Evolution 32: 99–104.Google Scholar
Charlesworth, B. 1994. Evolution in age-structured populations, second edition. Cambridge University Press, England.Google Scholar
Fisher, R. A. 1918. The correlation between relatives on the supposition of Mendelian inheritance. Royal Society of Edinburgh, Transactions 52: 399–433.Google Scholar
Hill, W. G. 1974. Prediction and evaluation of response to selection with overlapping generations. Animal Production 18: 117–139.Google Scholar
Hirotani, A. 1994. Dominance rank, copulatory behaviour and estimated reproductive success in male reindeer. Animal Behaviour 48: 929–936.Google Scholar
Hopkins, I. R. and James, J. W. 1978. Theory of nucleus breeding schemes with overlapping generations. Theoretical and Applied Genetics 53: 17–24.Google Scholar
Hopkins, I. R. and James, J. W. 1979. Genetic responses in the early years of selection programmes using genetic differences between generations. Animal Production 28: 65–77.Google Scholar
James, J. W. 1977. Open nucleus breeding systems. Animal Production 24: 287–305.Google Scholar
Khombe, C. T. 1998. A description of the response in weaning weight realised in one generation when improved bulls are introduced into a randomly mating unimproved population. Proceedings of the sixth world congress on genetics applied to livestock production, Armidale, vol. 25, pp. 285–288.Google Scholar
McClintock, A. E. and Cunningham, E. P. 1974. Selection in dual purpose cattle populations: defining the breeding objective. Animal Production 18: 237–247.Google Scholar
Mohiuddin, G. 1993. Estimates of genetic and phenotypic parameters of some performance traits in beef cattle. Animal Breeding Abstracts 61: 495–522.Google Scholar
Petersson, C. J. and Danell, Ö. 1992. Simulated production losses in reindeer herds caused by accidental death of animals. Rangifer 12: 143–150.Google Scholar
Reinsch, N. and Kalm, E. 1995. Gene-flow and relative importance of maternal, paternal and direct effects in dairy cattle. Archives of Animal Breeding 38: 355–366.Google Scholar
Willham, R. L. 1972. The role of maternal effects in animal breeding. III. Biometrical aspects of maternal effects in animals. Journal of Animal Science 35: 1288–1293.Google Scholar