Hostname: page-component-8448b6f56d-m8qmq Total loading time: 0 Render date: 2024-04-24T18:51:19.867Z Has data issue: false hasContentIssue false

A comparison of alternative nucleus breeding systems and a sire referencing scheme for sheep improvement

Published online by Cambridge University Press:  02 September 2010

J. A. Roden
Affiliation:
Department of Agriculture, University of Aberdeen, 581 King Street, Aberdeen AB24 5UA
Get access

Abstract

Stochastic simulation was used to compare selection response and rate of inbreeding in four nucleus breeding systems and a sire referencing scheme for sheep: an open nucleus system (ONS), an open nucleus system with sequential selection of the nucleus (ONS-S), a sire referencing scheme (SRS) and a dispersed open nucleus system (DONS). Selection was based on best linear unbiased prediction of breeding values for a single trait measurable on all individuals prior to selection. Selection in a population of 1200 ewes equally divided into 10 flocks was simulated over a 15-year period. The mean rate of genetic gain was proportionately about 0-15 higher in ONS-S and DONS compared with ONS and SRS. The rate of inbreeding in SRS was considerably lower and in ONS-S, considerably higher, than in the other systems. The level of prolificacy in the population did not influence the relative ranking of the breeding systems but may have implications for their optimal structure.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1996

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

Guy, D. R. and Croston, D. 1994. UK experience and progress with sheep sire referencing schemes. Proceedings of the fifth world congress on genetics applied to livestock production, Guelph, vol. 18, pp. 5558.Google Scholar
Harvey, T. G., Haydon, R., Blair, H. T., Daniell, D. and Hilson, R. 1990. Response to modern technology within the New Zealand sheep breeding industry. Proceedings of the New Zealand Society of Animal Production 50: 423426.Google Scholar
James, J. W. 1977. Open nucleus breeding systems Animal Production 24: 287305.Google Scholar
James, J. W. 1978. Effective population size in open nucleus breeding schemes Acta Agricultume Scandinavica 28: 387392.CrossRefGoogle Scholar
Kinghorn, B. P. and Shepherd, R. K. 1994. A tactical approach to breeding for information-rich designs. Proceedings of the fifth world congress on genetics applied to livestock production, Guelph, vol. 18, pp. 255261.Google Scholar
Mueller, J. P. and James, J. W. 1983. Effects of reduced variance due to selection in open-nucleus breeding systems. Australian journal of Agricultural Research 34: 5362.CrossRefGoogle Scholar
Nicholas, F. W. 1989. Incorporatio n of new reproductive technology in genetic improvement programmes. In Evolution and animal breeding — reviews on molecular and quantitative approaches in honour of Alan Robertson (ed. Hill, W. G. and Mackay, T. F. C.), pp. 201209. CAB International, Wallingford.Google Scholar
Parnell, P. F., Baker, R. L. and Foulley, J. L. 1986. The efficiency and place of multi-herd animal evaluation procedures for beef cattle. Proceedings of the third world congress on genetics applied to livestock production, Lincoln, Nebraska, vol. IX, pp. 373388.Google Scholar
Quirke, J. F. and Hanrahan, J. P. 1977. Comparison of the survival in the uteri of adult ewes of cleaved ova from adult ewes and ewe lambs, journal of Reproduction and Fertility 51: 487489.CrossRefGoogle ScholarPubMed
Rangel-Santos, R., McDonald, M. F. and Wickham, G. A. 1991. Evaluation of the feasibility of a juvenile MOET scheme in sheep. Proceedings of the New Zealand Society of Animal Production 51: 139142.Google Scholar
Roden, J. A. 1994. A simulation study of alternative nucleus breeding systems in a sheep population. Proceedings of the fifth world congress on genetics applied to livestock production, Guelph, vol. 18, pp. 302305.Google Scholar
Roden, J. A. 1995. A simulation study of open nucleus and closed nucleus breeding systems in a sheep population. Animal Science 60: 117124.CrossRefGoogle Scholar
Westell, R. A., Quass, R. L. and Van Vleck, L. D.Genetic groups in an animal model, journal of Dairy Science 71: 13101318.CrossRefGoogle Scholar
Wolf, B. T. and McDougall, I. 1994. Comparison of MOET in Texel ewe lambs and yearling ewes. Animal Production 58: 448 (abstr.).Google Scholar