Animal Genomics and Improvement Laboratory, ARS, USDA, Beltsville, MD 20705, USA, Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20705, USA, Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA and Department of Animal Science, Iowa State University, Ames, IA 50011, USA.|Animal Genomics and Improvement Laboratory, ARS, USDA, Beltsville, MD 20705, USA, Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20705, USA, Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA and Department of Animal Science, Iowa State University, Ames, IA 50011, USA.|Animal Genomics and Improvement Laboratory, ARS, USDA, Beltsville, MD 20705, USA, Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20705, USA, Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA and Department of Animal Science, Iowa State University, Ames, IA 50011, USA.|Animal Genomics and Improvement Laboratory, ARS, USDA, Beltsville, MD 20705, USA, Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20705, USA, Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA and Department of Animal Science, Iowa State University, Ames, IA 50011, USA.|Animal Genomics and Improvement Laboratory, ARS, USDA, Beltsville, MD 20705, USA, Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20705, USA, Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA and Department of Animal Science, Iowa State University, Ames, IA 50011, USA.|Animal Genomics and Improvement Laboratory, ARS, USDA, Beltsville, MD 20705, USA, Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20705, USA, Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA and Department of Animal Science, Iowa State University, Ames, IA 50011, USA.|Animal Genomics and Improvement Laboratory, ARS, USDA, Beltsville, MD 20705, USA, Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20705, USA, Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA and Department of Animal Science, Iowa State University, Ames, IA 50011, USA.|Animal Genomics and Improvement Laboratory, ARS, USDA, Beltsville, MD 20705, USA, Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20705, USA, Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA and Department of Animal Science, Iowa State University, Ames, IA 50011, USA.|Animal Genomics and Improvement Laboratory, ARS, USDA, Beltsville, MD 20705, USA, Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20705, USA, Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA and Department of Animal Science, Iowa State University, Ames, IA 50011, USA.|Animal Genomics and Improvement Laboratory, ARS, USDA, Beltsville, MD 20705, USA, Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20705, USA, Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA and Department of Animal Science, Iowa State University, Ames, IA 50011, USA.