1 Avian Immunobiology Laboratory, Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, Virginia, United States of America, 2 Animal Biosciences and Biotechnology Laboratory, USDA Agricultural Research Service, Beltsville, Maryland, United States of America, 3 Institute for Physical Science and Technology, University of Maryland, College Park, Maryland, United States of America, 4 Animal Breeding and Genomics Centre, Wageningen University, Wageningen, the Netherlands, 5 European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom, 6 Roche Applied Science, Indianapolis, Indiana, United States of America, 7 The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, United Kingdom, 8 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, United States of America, 9 Chromatin Inc., Champaign, Illinois, United States of America, 10 Department of Veterinary Sciences, Utah State University, Logan, Utah, United States of America, 11 Gene Expression and Genomics Unit, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America, 12 Department of Animal Science, University of California, Davis, California, United States of America, 13 Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America, 14 Department of Soil and Crop Sciences, Texas A&M University, College Station, Texas, United States of America, 15 Center for Bioinformatics and Computational Biology, University of Maryland, College Park, Maryland, United States of America, 16 Department of Computer Science and Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig, Germany, 17 LIFE Project, University of Leipzig, Leipzig, Germany, 18 Children's Hospital and Research Center at Oakland, Oakland, California, United States of America, 19 Institute for Animal Health, Compton, Berkshire, United Kingdom, 20 Laboratory of Bioinformatics and Population Genetics, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea, 21 Philipps-Universität Marburg, Pharmazeutische Chemie, Marburg, Germany, 22 Comparative Bioinformatics, Centre for Genomic Regulation (CRG), Universitat Pompeus Fabre, Barcelona, Spain, 23 Department of Computer Science, Virginia Tech, Blacksburg, Virginia, United States of America, 24 Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom, 25 Center for Bioinformatics and Computational Biology, Department of Computer Science, University of Maryland, College Park, Maryland, United States of America, 26 Department of Animal and Food Sciences, University of Delaware, Newark, Delaware, United States of America, 27 Bovine Functional Genomics Laboratory, USDA Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, Maryland, United States of America, 28 Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany, 29 Fraunhofer Institut für Zelltherapie und Immunologie, Leipzig, Germany, 30 Department of Theoretical Chemistry University of Vienna, Vienna, Austria, 31 Santa Fe Institute, Santa Fe, New Mexico, United States of America, 32 Department of Biochemistry, Virginia Tech, Blacksburg, Virginia, United States of America, 33 Animal Improvement Programs Laboratory, USDA Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, Maryland, United States of America, 34 Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, United States of America