animal

Breeding and genetics

Relative breed contributions to neutral genetic diversity of a comprehensive representation of Iberian native cattle

J. Cañóna1 c1, D. Garcíaa1, J. V. Delgadoa2, S. Dunnera1, L. Telo da Gamaa3, V. Landia2, I. Martín-Burriela4, A. Martíneza2, C. Penedoa5, C. Rodellara4, P. Zaragozaa4 and C. Ginjaa3a5

a1 Departamento de Producción Animal, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid, Spain

a2 Departamento de Genética, Universidad de Córdoba, Campus Rabanales C-5, 14071 Córdoba, Spain

a3 UIRGRMA-INIA, Instituto Nacional dos Recursos Biológicos, Fonte Boa, 2005-048 Vale de Santarém, Portugal

a4 Laboratorio de Genética Bioquímica, Facultad de Veterinaria, Universidad de Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain

a5 Veterinary Genetics Laboratory, University of California, One Shields Avenue, Davis, CA 95616, USA

Abstract

This study is aimed at establishing priorities for the optimal conservation of genetic diversity among a comprehensive group of 40 cattle breeds from the Iberian Peninsula. Different sets of breed contributions to diversity were obtained with several methods that differ in the relative weight attributed to the within- and between-breed components of the genetic variation. The contributions to the Weitzman diversity and the expected heterozygosity (He) account for between- and within-breed variation only, respectively. Contributions to the core set obtained for several kinship matrices, incorporate both sources of variation, as well as the combined contributions of Ollivier and Foulley and those of Caballero and Toro. In general, breeds that ranked high in the different core set applications also ranked high in the contribution to the global He, for example, Sayaguesa, Retinta, Monchina, Berrenda en Colorado or Marismeña. As expected, the Weitzman method prioritised breeds with low contributions to the He, like Mallorquina, Menorquina, Berrenda en Negro, Mostrenca, Vaca Palmera or Mirandesa, all showing highly negative contributions to He – that is, their removal would significantly increase the average He. Weighing the within- and between-breed components with the FST produced a balanced set of contributions in which all the breeds ranking high in both approaches show up. Unlike the other methods, the contributions to the diversity proposed by Caballero and Toro prioritised a good number of Portuguese breeds (Arouquesa, Barrosã, Mertolenga and Preta ranking highest), but this might be caused by a sample size effect. Only Sayaguesa ranked high in all the methods tested. Considerations with regard to the conservation scheme should be made before adopting any of these approaches: in situ v. cryoconservation, selection and adaptation within the breeds v. crossbreeding or the creation of synthetic breeds. There is no general consensus with regard to balancing within- and between-breed diversity and the decision of which source to favour will depend on the particular scenario. In addition to the genetic information, other factors, such as geographical, historical, economic, cultural, etc., also need to be considered in the formulation of a conservation plan. All these aspects will ultimately influence the distribution of resources by the decision-makers.

(Received September 10 2010)

(Accepted January 12 2011)

(Online publication March 11 2011)

Correspondence:

c1 E-mail: jcanon@vet.ucm.es

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