1. IFAS – Range Cattle Research and Education Center, University of Florida , Ona, FL 33865 , USA
2. Eastern Oregon Agricultural Research Center, Oregon State University , Burns, OR 97720 , USA
3. Livestock Issues Research Unit, ARS-USDA , Lubbock, TX 79403 , USA
4. College of Veterinary Medicine, University of Florida , Gainesville, FL 32610 , USA