1. Dep. of Animal Science São Paulo State Univ. via de acesso Professor Paulo Donato Castellane Jaboticabal SP 14884–900 Brazil
2. Embrapa Agrobiologia Rodovia BR 465, km 7 Seropédica RJ 23891‐000 Brazil
3. North Florida Research and Education Center Univ. of Florida Marianna FL 32446 USA