1. Animal Nutrition Master’s Program, Graduate School, University of Costa Rica, San Pedro, San José 2060, Costa Rica
2. Forage Extension Specialist, Mississippi State University, Starkville, MS 39762, USA
3. Southwest Research and Extension Center, Division of Agriculture, University of Arkansas, Hope, AR 71801, USA
4. Department of Animal Science and Research Center for Animal Nutrition, Campus Rodrigo Facio, University of Costa Rica, San Pedro, San José 2060, Costa Rica