1. Departamento de Zootecnia; USP/ESALQ; Piracicaba SP 13418-900 Brazil
2. Department of Genetics and Genomics; The Roslin Institute and Royal School of Veterinary Studies; Midlothian EH25 9PS UK
3. Departamento de Genética; USP/ESALQ; Piracicaba SP 13418-900 Brazil
4. Embrapa Suínos e Aves; Concórdia SC 89700-000 Brazil