Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-20T13:27:10.570Z Has data issue: false hasContentIssue false
  • English
  • Français

Studies on a selection index for improvement of litter weight in sheep

Published online by Cambridge University Press:  02 September 2010

T. G. Martin  and
C. Smith
T. G. Martin
Affiliation:
ARC Animal Breeding Research Organisation, West Mains Road, Edinburgh EH9 3JQ
C. Smith
Affiliation:
ARC Animal Breeding Research Organisation, West Mains Road, Edinburgh EH9 3JQ
Get access

Abstract

The value of a selection index for 8-week litter weight as a trait of the ewe, combining information on the ewe and on five classes of female relatives, was considered. Adding records on the dam and on paternal half sibs to those of the ewe gives increases of 10 to 50% in the rates of genetic response. The index can be simplified with little loss in efficiency by weighting all records equally for relatives with 1, 2 or more records within each class of relative. In selecting breeding replacements, information on the parents of the sire of the individual being selected may increase the rates of response by a further 20 to 30 %.

Type
Research Article
Information
Animal Production , Volume 31 , Issue 1 , August 1980 , pp. 81 - 85
Copyright
Copyright © British Society of Animal Science 1980

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

Cunningham, E. P. 1970. Selind: a Fortran computer program for genetic selection indices. Agricultural Institute, Castleknock, Co. Dublin. Eire.Google Scholar
Martin, T. G., Sales, D. I., Smith, C. and Nicholson, D. 1980. Phenotypic and genetic parameters for lamb weights in a synthetic line of sheep. Anim. Prod. 30: 261–269.Google Scholar
Robertson, A. 1977. The effect of selection on the estimation of genetic parameters. Z. Tierziicht. ZiichtBiol. 94: 131–135.CrossRefGoogle Scholar
Sales, Jill and Hill, W. G. 1976. Effect of sampling errors on efficiency of selection indices. 2. Use of information on associated traits for improvement of a single important trait. Anim. Prod. 23: 1–14.Google Scholar
Smith, C., King, J. W. B., Nicholson, D., Wolf, B. T. and Bampton, P. R. 1979. Performance of crossbred sheep from a synthetic dam line. Anim. Prod. 29: 1–9.Google Scholar