1. Animal Science College, São Paulo State University (UNESP), Dracena, São Paulo, Brazil 17900-00
2. Department of Breeding and Animal Nutrition, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil 18618-000
3. Brazilian Institute of Geography and Statistics (IBGE), Pirassununga, São Paulo, Brazil 13630-095
4. Department of Animal Nutrition and Production, University of São Paulo (USP), Pirassununga, São Paulo, Brazil 13635-900