Combining Gene-Based Methods and Reproductive Technologies to Enhance Genetic Improvement of Livestock in Developing Countries

  • Julius van der Werf
  • Karen Marshall
Conference paper

Abstract

Selection based on DNA markers is most useful for traits that are hard to measure and have low heritability. It allows earlier and more accurate selection, increasing short- and medium-term selection response, and may aid in targeting genotypes for specific production environments or markets. The use of genotypic information in breeding programmes for within-breed selection will generally have limited extra benefit, unless selection based on phenotype is difficult or advanced reproductive technologies are used. Novel reproductive technologies boost reproductive rates of breeding animals and may allow reproduction at juvenile ages. The benefit arises from increased selection intensity, as well as from increased selection accuracy due to larger families and decreased generation interval, as higher reproductive rates result in lower optimal ages for breeding animals. Increased reproductive rates and early selection rely more on between-family selection and potentially decrease effective population size, therefore increasing inbreeding. Selection needs to be optimized with respect to inbreeding and merit. Extra benefit from scenarios with unlimited use of reproductive technologies is restricted by the need to maintain genetic diversity. Benefits from marker assisted selection are higher in breeding programmes that use reproductive technologies, as the value of providing information about genotype is more beneficial for selection of young animals before they have a phenotype. Moreover, genotype information exploits variation within families, which is beneficial in breeding programmes where loss of genetic diversity is to be controlled. In developing countries, use of genotype information is likely to be most useful in marker assisted introgression programmes, where valuable genes are introgressed from one breed into another. A large variety of genetic resources in developing countries exists across breeds and populations, and utilization and management of this variation might greatly benefit from gene technologies.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Gibson, J.P. 1994. Short-term gain at the expense of long-term response with selection of identified loci. Proceedings of the 5th World Congress on Genetics Applied to Livestock Production, 21-201.Google Scholar
  2. Lande, R. & Thompson, R. 1990. Efficiency of marker-assisted selection in the improvement of quantitative traits. Genetics, 124: 743–756.PubMedGoogle Scholar
  3. Marshall, K. 2002. Marker assisted selection in the Australian sheepmeat industry. PhD thesis, University of New England, Armidale, Australia.Google Scholar
  4. Marshall, K., Henshall, J. & an der Werf, J.H.J. 2002. Response from marker-assisted selection when various proportions of animals are marker typed: a multiple trait simulation study relevant to the sheepmeat industry. Animal Science, 74: 223–232.Google Scholar
  5. Meuwissen, T.H.E. 1997. Maximizing the response of selection with a predefined rate of inbreeding. Journal of Animal Science, 75: 934–940.PubMedGoogle Scholar
  6. Meuwissen, T.H.E. & Goddard, M.E. 1996. The use of marker haplotypes in animal breeding schemes. Genetics Selection Evolution, 28: 161–176.Google Scholar
  7. Meuwissen, T.H.E., Hayes, B.J. & Goddard, M.E. 2001. Prediction of total genetic value using genome-wide dense marker maps. Genetics, 157: 1819–1829.PubMedGoogle Scholar
  8. Soller, M. & Medjugorac, I. 1999. A successful marriage: making the transition from QTL mapping to marker-assisted selection. pp. 85–96, in: J.C.M. Dekkers, S.J. Lamont and M.F. Rothschild (eds). From Jay Lush to Genomics: Visions for Animal Breeding and Genetics. Proceedings of a conference. Ames, Iowa, 16–18 May 1999. See: http://www.agbiotechnet.com/proceedings/jaylush.aspGoogle Scholar
  9. Spelman, R. & Garrick, D. 1997. Utilisation of marker assisted selection in a commercial dairy cow population. Livestock Production Science, 47: 139–147.CrossRefGoogle Scholar
  10. Van Arendonk, J.A.M. & Bijma, P. 2003. Factors affecting commercial application of embryo technologies in dairy cattle in Europe — a modelling approach. Theriogenology, 59: 635–649.PubMedGoogle Scholar
  11. Visscher, P.M. & Haley, C.S. 1995. Utilizing genetic markers in pig breeding programs. Animal Breeding Abstracts, 63: 1–8.Google Scholar
  12. Woolliams, J.A., Pong-Wong, R., & Villanueva, B. 2002. Strategic optimization of short-and long term gain and inbreeding in MAS and non-MAS schemes. Proceedings of the 7th World Congress on Genetics Applied to Livestock Production. Communication No. 23-02. INRA, France.Google Scholar

Copyright information

© IAEA 2005

Authors and Affiliations

  • Julius van der Werf
    • 1
  • Karen Marshall
    • 1
  1. 1.School of Rural Science and AgricultureUniversity of New EnglandArmidaleAustralia

Personalised recommendations