1. USDA, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, Nebraska, USA
2. Texas A&M AgriLife Research, Texas A&M University System, College Station, Texas, USA
3. Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
4. Veterinary and Biomedical Research Center, Inc., Manhattan, Kansas, USA
5. College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA