Hostname: page-component-848d4c4894-sjtt6 Total loading time: 0 Render date: 2024-06-29T11:47:38.742Z Has data issue: false hasContentIssue false
  • English
  • Français

Selection in a population with overlapping generations

Published online by Cambridge University Press:  02 September 2010

Maurice Bichard ,
A. H. R. Pease ,
P. H. Swales  and
K. Özkütük
Maurice Bichard
Affiliation:
Department of Agriculture, The University, Newcastle upon Tyne, NE1 7RU
A. H. R. Pease
Affiliation:
Department of Agriculture, The University, Newcastle upon Tyne, NE1 7RU
P. H. Swales
Affiliation:
Department of Agriculture, The University, Newcastle upon Tyne, NE1 7RU
K. Özkütük
Affiliation:
Department of Agriculture, The University, Newcastle upon Tyne, NE1 7RU
Get access

Summary

A theoretical investigation is reported into the effects of overlapping generations on the prediction of genetic gain from repeated within-population truncation selection for a quantitative trait. The gain resulting from the selection process produces genetic differences between the groups of breeding animals of different ages, and between the means of their progeny. These differences are not allowed for in the usual prediction formula. The correct allowances to make for the genetic effects of maternal age are derived for a simple situation. The implications of these allowances on the overall rate of genetic progress, and on the optimum age structure for maximum progress, are shown in a model pig breeding programme. The normal prediction formula underestimates the genetic gain which can be achieved if females are kept for five litters by 10 to 12%, and overestimates the disadvantages of keeping females for more than one or two litters.

Type
Research Article
Information
Animal Production , Volume 17 , Issue 3 , December 1973 , pp. 215 - 227
Copyright
Copyright © British Society of Animal Science 1973

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

Abramowitz, M. and Stegun, A. (ed.) 1964. Handbook of Mathematical Functions with Formulas, Graphs and Mathematical Tables. U.S. National Bureau of Standards, Applied Mathematics Series: 55.Google Scholar
Bichard, M. 1971. Dissemination of genetic improvement through a livestock industry. Anim. Prod. 13: 401–411.Google Scholar
Dickerson, G. E. and Hazel, L. N. 1944a. Effectiveness of selection on progeny performance as a supplement to earlier culling in livestock. J. agric. Res. 69: 459–475.Google Scholar
Dickerson, G. E. and Hazel, L. N. 1944b. Selection for growth rate of pigs and productivity of sows. J. Anim. Sci. 3: 201–212.CrossRefGoogle Scholar
Falconer, D. S. 1960. Introduction to Quantitative Genetics. Oliver and Boyd, Edinburgh.Google Scholar
Fisher, R. A. and Yates, F. 1963. Statistical Tables for Biological, Agricultural and Medical Research. 6th ed. Oliver and Boyd, Edinburgh.Google Scholar
Hetzer, H. O., Comstock, R. E., Zeller, J. H., Hiner, R. L. and Harvey, W. R. 1961. Combining abilities in crosses among six inbred lines of swine. Tech. Bull. U.S. Dep. Agric, No. 1237.Google Scholar
Lush, J. L. 1947. Family merit and individual merit as bases for selection. Part I. Am. Ata. 81:241–261.Google Scholar
Neimann-Sørensen, A. and Robertson, Alan. 1961. The association between bloodgroups and several production characteristics in three Danish cattle breeds. Ada Agric. scand. 11: 163–196.CrossRefGoogle Scholar
Rendel, J. M. and Robertson, Alan. 1950. Estimation of genetic gain in milk yield by selection in a closed herd of dairy cattle. J. Genet. 50: 1–8.CrossRefGoogle Scholar
Strang, G. S. 1970. Litter productivity in Large White pigs. 1. The relative importance of some sources of variation. Anim. Prod. 12: 222–233.Google Scholar