1. Arbeitsgruppe Pferd, Heinrich-Roettgen-Str. 20, 52428 Juelich, Germany.
2. Facultad de Veterinaria, Universidad Nacional del Litoral, 3080 Esperanza, Argentina.
3. Department of Animal Science, University of Sao Paulo State, Dracena Campus, Dracena, 17900-00, Brazil.
4. Haras José Lucio Nuniez, Paraná, 3100, Argentina.