1. Animal Science Dep. Univ. Federal Rural de Pernambuco Recife PE Brazil
2. North Florida Research and Education Center Univ. of Florida 3925 Highway 71 Marianna FL 32446 USA
3. U.S. Dairy Forage Research Center USDA‐ARS 2615 Yellowstone Dr. Marshfield WI 54449 USA
4. Dep. Animal Science São Paulo State Univ. via de acesso Prof. Paulo Donato Castellane Jaboticabal SP 14884‐900 Brazil
5. EMBRAPA Agrobiology km 7 BR 465, s/n, Bairro Ecologia Seropedica RJ CEP 23891‐000 Brazil