1. School of Veterinary Science, The University of Queensland, Gatton Campus, QLD 4343, Australia
2. Commonwealth Scientific and Industrial Research Organization Livestock Industries, Queensland Bioscience Precinct, Brisbane, QLD 4067, Australia
3. Cooperative Research Centre for Beef Genetic Technologies, Australia
4. USDA-ARS, U.S. Meat Animal Research Center, Clay Center, NE 68933, USA
5. Department of Animal and Range Sciences, New Mexico State University, Las Cruces 88003
6. Department of Animal Sciences, University of California, Davis 95616
7. Department of Animal Sciences, Colorado State University, Fort Collins 80523