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Maternal effects and selection response with an application to sheep data

Published online by Cambridge University Press:  02 September 2010

J. P. Hanrahan
Affiliation:
The Agricultural Institute, Belclare, Tuam, Co. Galway, Ireland
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Summary

The implications of genetic variation in maternal performance for the relative merits of common selection strategies have been investigated. If the accuracy of progeny testing is computed without taking maternal effects into account, the estimate is biased upward. This bias increases as the correlation between direct and maternal genetic effects decreases from positive to negative values. The relative efficiency of progeny and performance test selection is a function of the heritability of direct and maternal genetic effects and the correlation between them. In terms of genetic gain per unit time, progeny testing is almost always less efficient than performance testing. For sire line improvement progeny testing is relatively more useful but is still likely to be less efficient than performance test selection unless there is a negative correlation between direct and maternal genetic effects or the correlation between purebred and crossbred direct genetic effects is very low or negative.

Analysis of body weight at 6 and 14 weeks of age in Galway sheep has shown that maternal genetic effects are an important source of variation in this population.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1976

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References

REFERENCES

Bowman, J. C. 1968. Genetic variation of body weight in sheep. In Growth and Development of Mammals (ed. Lodge, G. A. and Lamming, G. E.). Butterworth, London.Google Scholar
Ch'Ang, T. S. and Rae, A. L. 1972. The genetic basis of growth, reproduction, and maternal environment in Romney ewes. II. Genetic covariation between hogget characters, fertility, and maternal environment of the ewe. Aust. J. agric. Res. 23: 149165.CrossRefGoogle Scholar
Cochran, W. G. 1951. Improvement by means of selection. Proc. 2nd Berkeley Symp. Math. Stat. and Prob., pp. 449470.Google Scholar
Dickerson, G. E. 1947. Composition of hog carcasses as influenced by heritable differences in rate and economy of gain. Res. Bull. Iowa agric. Exp. Stn, No. 354, pp. 489524.Google Scholar
Falconer, D. S. 1960. Introduction to Quantitative Genetics. Oliver and Boyd, Edinburgh.Google Scholar
Hanrahan, J. P. and Eisen, E. J. 1973. Sexual dimorphism and direct and maternal genetic effects on body weight in mice. Theor. appl. Genet. 43: 3945.CrossRefGoogle ScholarPubMed
Hanrahan, J. P. and Eisen, E. J. 1974. Genetic variation in litter size and 12-day weight n i mice and their relationships with post-weaning growth. Anim. Prod. 19: 1323.Google Scholar
Hanrahan, J. P., Eisen, E. J. and Legates, J. E. 1973. Effects of population size and selection intensity on short-term response to selection for postweaning gain in mice. Genetics, Austin, Tex. 73: 513530.CrossRefGoogle ScholarPubMed
Pattie, W. A. 1965. Selection for weaning weight in Merino sheep. 1. Direct response to selection. Aust. J. Exp. agric. Anim. Husb. 5: 353360.CrossRefGoogle Scholar
Turner, H. N. and Young, S. S. Y. 1969. Quantitative Genetics in Sheep Breeding. Macmillan, London.Google Scholar
Van Vleck, L. D. 1970. Index selection for direct and maternal genetic components of economic traits. Biometrics 26: 477483.CrossRefGoogle ScholarPubMed
Van Vleck, L. D. 1973. Selection for direct and maternal genetic effects. In Genetics Lectures (ed. Bogart, R.), 3: 133148. Oregon State Univ. Press, Corvallis, Oregon.Google Scholar
Vesely, J. A., Peters, H. F., Slen, S. B. and Robison, O. W. 1970. Heritabilities and genetic correlations in growth and wool traits of Rambouillet and Romnelet sheep. J. Anim. Sci. 30: 174181.CrossRefGoogle ScholarPubMed
Vinson, W. E., Eisen, E. J. and Robison, O. W. 1969. Predicted response to selection for crossbred performance in mice. J. Anim. Sci. 28: 725733.CrossRefGoogle ScholarPubMed
Willham, R. L. 1963. The covariance between relatives for characters composed of components contributed by related individuals. Biometrics 19: 1827.CrossRefGoogle Scholar