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Conservation of livestock breed diversity

Published online by Cambridge University Press:  01 August 2011

J.S.F. Barker
Affiliation:
Department of Animal Science, University of New England, Armidale, NSW 2351, Australia
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Summary

Mankind uses some 40 species of animals as domestic livestock to meet our needs for food, clothing, power, etc. Within these species, there are in total some 4,500 breeds that are referred to as the global animal genetic resources. Each breed comprises a unique set of genes. More than 30% of breeds are estimated to be at risk of extinction, and many more, particularly in developing countries, are threatened by inefficient utilization. The Food and Agriculture Organization of the United Nations has been mandated by its member nations to manage the global animal genetic resources, and major progress has been made in the last few years. However, resources are limited, and priorities will have to be set for breed conservation, for breed development programmes and for evaluation studies. Breeds that are taxonomically distinct should be favoured for conservation, the objective being to maintain maximum genetic diversity of each livestock species. Genetic distances and phylogenetic diversity provide the best available objective criterion, and microsatellites are the current markers of choice for obtaining the genetic data. Microsatellite-based genetic distances will describe breed similarities due to common ancestry, but cannot account for consequences of artificial or natural selection. Phylogenetic trees for 11 water buffalo populations in southeast Asia, constructed using 25 polymorphic protein coding loci or 21 microsatellite loci, show differences in both topology and branch lengths, but the microsatellite tree is a better representation of the similarities due to common ancestry. Thus phylogenetic diversity, based on microsatellite loci, should be used as an initial guide in making conservation decisions for livestock breeds.

Resumen

El Hombre utiliza unas 40 especies animales como ganado doméstico para satisfacer sus necesidades de alimentación, ropa, tracción, etc. Dentro de estas especies, existe un total de 4 500 razas conocidas como recursos genéticos animales globales. Cada raza comprende un grupo único de genes. Se estima que más del 30% de las razas están en peligro de extinción y muchas más, sobre todo en los países en vías de desarrollo, están amenazadas por una utilización ineficaz. La Organización para la Alimentación y la Agricultura de las Naciones Unidas ha sido encomendada por sus naciones miembros de gestionar los recursos genéticos animales globales. Se han hecho grandes progresos en este sentido en los últimos años, sin embargo, los recursos son limitados, y será necesario establecer prioridades para la conservación de razas, para programas de desarrollo de razas y para estudios de evaluación. Las razas taxonómicamente diferentes deberían ser favorecidas para la conservación, ya que el objetivo es de mantener la máxima diversidad genética de cada especie ganadera. Las distancias genéticas y la diversidad filogenética proporcionan el mejor criterio objetivo disponible y los microsatélites son actualmente los marcadores elegidos para obtener los datos genéticos. Las distancias genéticas basadas en microsatélites describirán las similitudes entre razas debido a sus antecedentes comunes pero no podrán explicar las consecuencias de la selección artificial ni natural. Arboles filogenéticos para 11 poblaciones de búfalos de agua en el sudeste de Asia, elaborados utilizando 25 loci polimórficos codificadores de proteína o 21 loci de microsatélites, muestran diferencias tanto en topología como longitudes de ramas, pero el árbol de microsatélites es una mejor representación de las similitudes debidas a antecesores comunes. Por consiguiente, la diversidad filogenética, basada en loci de microsatélites, debería utilizarse como una guía inicial para tomar decisiones sobre la conservación de razas ganaderas.

Type
Research Articles
Copyright
Copyright © Food and Agriculture Organization of the United Nations 1999

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References

Alderson, L. (Ed.) 1990. Genetic Conservation of Domestic Livestock. CAB International, Wallingford.Google Scholar
Amos, B. & Hoelzel, A.R. 1992. Applications of molecular genetic techniques to the conservation of small populations. Biol. Conserv., 61: 133144.CrossRefGoogle Scholar
Barker, J.S.F. 1980. Animal genetic resources in Asia and Oceania - The perspective, pp. 1319 in Proc. SABRAO Workshop on Animal Genetic Resources in Asia and Oceania. Tropical Agriculture Research Center, Tsukuba, Japan.Google Scholar
Barker, J.S.F. 1985. Identifying the breeds to be evaluated, in Evaluation of Large Ruminants for the Tropics: proceedings of an International Workshop held at CSIRO, Rockhampton, Qld, Australia, 19–23 March, 1984, edited by Copland, J.W.. ACIAR Proceedings, 5: 161166.Google Scholar
Barker, J.S.F. 1992. Proposals for an action program for animal genetic resources in the AAAP region. Proc. 6th AAAP Animal Science Congress, 1: 229238.Google Scholar
Barker, J.S.F. 1994. Animal breeding and conservation genetics, pp. 381395 in Conservation Genetics, edited by Loeschcke, V., Tomiuk, J. and Jain, S.K.. Birkhäuser Verlag, Basel.CrossRefGoogle ScholarPubMed
Barker, J.S.F., Tan, S.G., Selvaraj, O.S. & Mukherjee, T.K. 1997a. Genetic variation within and relationships among populations of Asian water buffalo (Bubalus bubalis). Animal Genetics, 28: 113.CrossRefGoogle ScholarPubMed
Barker, J.S.F., Moore, S.S., Hetzel, D.J.S., Evans, D., Tan, S.G. & Byrne, K. 1997b. Genetic diversity of Asian water buffalo (Bubalus bubalis): Microsatellite variation and a comparison with protein-coding loci. Animal Genetics, 28: 103115.CrossRefGoogle Scholar
Bruford, M.W. & Wayne, R.K. 1993. Microsatellites and their application to population genetic studies. Current Opinion in Genetics and Development, 3: 939943.CrossRefGoogle ScholarPubMed
Buchanan, F.C., Adams, L.J., Littlejohn, R.P., Maddox, J.F. & Crawford, A.M. 1994. Determination of evolutionary relationships among sheep breeds using microsatellites. Genomics, 22: 397403.CrossRefGoogle ScholarPubMed
Estoup, A., Garnery, L., Solignac, M. & Cornuet, J-M. 1995. Microsatellite variation in honey bee (Apis mellifera L.) populations: hierarchical genetic structure and test of the infinite allele and stepwise mutation models. Genetics, 140: 679695.CrossRefGoogle ScholarPubMed
FAO 1984. Animal genetic resources conservation by management, data banks and training. FAO Animal Production and Health Paper 44/1. FAO, Rome. pp. 186.Google Scholar
FAO 1992. The management of global animal genetic resources. FAO Animal Production and Health Paper 104. FAO, Rome. pp. 309.Google Scholar
FAO 1993. An integrated global programme to establish the genetic relationships among the breeds of each domestic animal species. FAO Division of Animal Production and Health, Report of a Working Group. Mimeo, pp. 32.Google Scholar
FAO 1995. World Watch List for Domestic Animal Diversity. 2nd Ed. FAO, Rome.Google Scholar
FAO 1996. Global project for the measurement of domestic animal diversity (MoDAD). FAO Animal Production and Health Paper, Rome.Google Scholar
Franklin, I.R. 1981. Population size and the genetic improvement of animals. In Future Developments in the Genetic Improvement of Animals, edited by Barker, J.S.F., Hammond, K. and McClintock, A.E.. Academic Press Australia, Sydney, 181196Google Scholar
Goldstein, D.B., Linares, A.R., Cavalli-Sforza, L.L. & Feldman, M.W. 1995. An evaluation of genetic distances for use with microsatellite loci. Genetics, 139: 463471.CrossRefGoogle ScholarPubMed
Hall, S.J.G. & Bradley, D.G. 1995. Conserving livestock breed biodiversity. Trends in Ecology and Evolution, 10: 267270.CrossRefGoogle ScholarPubMed
Hill, W.G., & Keightley, P.D. 1988. Interrelations of mutation, population size, artificial and natural selection. In Proc. Second Internat. Conf. Quant. Genet., edited by Weir, B.S., Eisen, E.J., Goodman, M.M. and Namkoong, G. Sinauer, Sunderland, 5770Google Scholar
Krajewski, C. 1994. Phylogenetic measures of biodiversity: a comparison and critique. Biol. Conserv., 69: 3339.CrossRefGoogle Scholar
MacHugh, D.E., Loftus, R.T., Bradley, D.G., Sharp, P.M. & Cunningham, P. 1994. Microsatellite DNA variation within and among European cattle breeds. Proc. Roy. Soc. Lond. B, 256: 2531.Google ScholarPubMed
Meghen, C., MacHugh, D.E. & Bradley, D.G. 1994. Genetic characterization and West African cattle. World Anim. Rev., 78: 5966.Google Scholar
Miller, R.H. 1977. The need for and potential application of germplasm preservation in cattle. J. Hered., 68: 365374.CrossRefGoogle Scholar
Nei, M. 1978. Estimation of average heterozygosity and genetic distance from a small number of individuals. Genetics, 89: 583590.CrossRefGoogle ScholarPubMed
Nei, M. 1987. Molecular Evolutionary Genetics. Columbia University Press, New York.CrossRefGoogle Scholar
Nei, M., Tajima, F. & Tateno, Y. 1983. Accuracy of estimated phylogenetic trees from molecular data II. Gene frequency data. J. Mol. Evol., 19: 153170.CrossRefGoogle ScholarPubMed
Pemberton, J.M., Slate, J., Bancroft, D.R., & Barrett, J.A. 1995. Non-amplifying alleles at microsatellite loci: a caution for parentage and population studies. Molec. Ecol., 4: 249252.CrossRefGoogle Scholar
Reynolds, J., Weir, B.S. & Cockerham, C.C. 1983. Estimation of the co-ancestry coefficient: basis for a short term genetic distance. Genetics, 105: 767779.CrossRefGoogle Scholar
Saitou, N. & Nei, M. 1987. The neighbour-joining method: a new method for reconstructing phylogenetic trees. Mol. Biol. Evol., 4: 406425.Google Scholar
Turton, J. 1974. The collection, storage and dissemination of information on breeds of livestock. Proc. 1st Wld Cong. Genet. Appl. Livestock Prod., 2: 6174.Google Scholar
Witting, L. & Loeschcke, V. 1995. The optimization of biodiversity conservation. Biol. Conserv., 71: 205207.CrossRefGoogle Scholar
van Zeveren, A., Peelman, L., van de Weghe, A. & Bouquet, Y. 1995. A genetic study of four Belgian pig populations by means of seven microsatellite loci. J. Anim. Breed. Genet., 112: 191204.CrossRefGoogle Scholar