1. Departament of Breeding and Animal Nutrition, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil 18618-000
2. North Florida Research and Education Center, University of Florida, Marianna 32446
3. Departament of Animal Nutrition and Production, University of São Paulo, Pirassununga, São Paulo, Brazil 13635-900
4. Department of Veterinary Medicine, Santa Catarina State University, Lages, Santa Catarina, Brazil 88520-000
5. Department of Animal Science, University of Minnesota, Saint Paul 55108