1. School of Agribusiness and Agriscience, Middle Tennessee State University, Horse Science Center, 314 W. Thompson Ln, Murfreesboro, TN 37129, USA
2. Departments of Animal Science and Large Animal Clinical Sciences, Michigan State University, 784 Wilson Road, East Lansing, MI 48824-1314, USA
3. Equine Studies Group, WALTHAM Centre for Pet Nutrition,, Freeby Lane, Waltham on the Wolds LE14 4RT, United Kingdom