1. Animal Science Department, State University of Western Parana, Marechal Cândido Rondon , PR , Brazil
2. Forage-Animal Production Research Unit, USDA-ARS , Lexington, KY , USA
3. Department of Animal Science, University of Tennessee , Knoxville, TN , USA
4. Department of Animal and Food Science, University of Kentucky , Lexington, KY , USA