1. Department of Animal Genetics; Centre for Research in Agricultural Genomics (CRAG); CSIC-IRTA-UAB-UB; Campus Universitat Autònoma de Barcelona Bellaterra 08193 Spain
2. Instituto Canario de Investigaciones Agrarias; La Laguna 38108 Tenerife Spain
3. INRA-GenPhySE-Génétique; Physiologie et Systèmes d'Elevage-UMR1388; 24 Chemin de Borde Rouge-Auzeville CS 52627 31326 Castanet Tolosan Cedex France