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Effect of sampling errors on efficiency of selection indices 1. Use of information from relatives for single trait improvement

Published online by Cambridge University Press:  02 September 2010

Jill Sales  and
W. G. Hill
Jill Sales
Affiliation:
Institute of Animal Genetics, Edinburgh EH9 3JN
W. G. Hill
Affiliation:
Institute of Animal Genetics, Edinburgh EH9 3JN
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Summary

An analysis is undertaken of the effect of errors in estimates of parameters, particularly the intra-class correlations, on the response from selection for one trait using an index of individual together with full- and/or half-sib family records. A distinction is drawn between the response (R) possible with use of the optimum index, that predicted (R) and that achieved (R*) with an index which uses the sample estimates of the parameter values.

It is found that the loss of efficiency (R*–R) using sample estimates is very small even for estimates far from the correct value. R is more sensitive to errors, particularly of the heritability and phenotypic variance estimates. Since the latter also appear in the prediction of response from individual selection, errors in predicting the relative responses from index and individual selection are small. Expected values of the proportional loss in response,

are approximately proportional to the variance of the estimate of intra-class correlation. It is shown that in practice initial experiments with 20 or so families may be sufficient to get average proportional losses down to less than 1%.

Type
Research Article
Information
Animal Production , Volume 22 , Issue 1 , February 1976 , pp. 1 - 17
Copyright
Copyright © British Society of Animal Science 1976

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References

Bulmer, M. G. 1971. The effect of selection on genetic variability. Am. Nat. 105:201–211.CrossRefGoogle Scholar
Fisher, R. A. 1925. Statistical Methods for Research Workers. Oliver and Boyd, Edinburgh.Google Scholar
Gill, J. L. and Jensen, E. L. 1968. Probability of obtaining negative estimates of heritability. Biometrics 24: 517–526.CrossRefGoogle ScholarPubMed
Harris, D. L. 1963. The influence of errors of parameter estimation upon index selection. In Statistical Genetics and Plant Breeding (ed. Hanson, W. D. and Robinson, H. F.), pp. 491–500. Publ. 982. National Academy of Sciences—National Research Council, Washington, D.C.Google Scholar
Harris, D. L. 1964. Expected and predicted progress from index selection involving estimates of population parameters. Biometrics 20: 46–72.CrossRefGoogle Scholar
Hazel, L. N. 1943. The genetic basis for constructing selection indexes. Genetics, Princeton 28: 476–490.CrossRefGoogle ScholarPubMed
Henderson, C. R. 1963. Selection index and expected genetic advance. In Statistical Genetics and Plant Breeding (ed. Hanson, W. D. and Robinson, H. F.), pp. 141–163. Publ. 982. National Academy of Sciences—National Research Council, Washington, D.C.Google Scholar
Hill, W. G. 1974. Heritabilities: estimation problems and the present state of information. In 1st Wld Cong. Genet, appl. Livestock Prod. 1: 343–351. Editorial Garsi, Madrid.Google Scholar
Lush, J. L. 1947. Family merit and individual merit as bases for selection. Am. Nat. 81: 241–261; 362–379.CrossRefGoogle Scholar
Mao, I. L. 1971. The effect of parameter estimation errors on the efficiency of index selection and on the accuracy of genetic gain prediction. Ph.D. Thesis, Cornell University, Ithaca, New York.Google Scholar
Osborme, R. 1957. The use of sire and dam family averages in increasing the efficiency of selective breeding under a hierarchical mating system. Heredity, Lond. 11: 93–116.CrossRefGoogle Scholar
Pig Industry Development Authority. 1965. Combined Testing. Recommendations by the Statistics Section for the Selection Index, (Mimeograph). DA 188. Pig Industry Development Authority, London.Google Scholar
Wilson, S. P. 1974. An experimental comparison of individual, family and combination selection. Genetics, Princeton 76: 823–836.CrossRefGoogle ScholarPubMed