1. Department of Anatomy, Physiology & Pharmacology, Auburn University, Auburn, Alabama 36849
2. Department of Large Animal Clinical Sciences, University of Tennessee, Knoxville, Tennessee 37996
3. Department of Animal Science, Berry College, Mt. Berry, Georgia 30149
4. School of Anatomy, Physiology and Human Biology, University of Western Australia, Perth, Crawley, Washington 6009, Australia
5. Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Victoria 3800, Australia
6. Animal Genomics and Improvement Laboratory, US Department of Agriculture, Agricultural Research Service, Beltsville, Maryland 20705
7. Division of Animal Sciences, University of Missouri, Columbia, Missouri 65211