1. Veterinary Diagnostic and Population Animal Medicine, Iowa State University, Ames, Iowa, USA
2. Pig Improvement Company, Hendersonville, Tennessee, USA
3. Department of Statistics, Iowa State University, Ames, Iowa, USA
4. Tosh Pork, Henry Tennessee, USA
5. Pipestone Veterinary Clinic, Pipestone, Minnesota, USA
6. Departamento de Clínica e Cirurgia Veterinárias, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
7. IDEXX laboratories, Westbrook, Maine, USA
8. Boehringer Ingelheim Animal Health USA, Inc., Atlanta, Georgia, USA
9. University of Cambridge, Cambridge, United Kingdom