1. Departamento
de Produccion Animal, Universidad Nacional de Colombia, Carrera
32 Chapinero, Palmira 763533, Colombia
2. Centro Internacional de Agricultura Tropical, Palmira 763537, Colombia
3. Massey
Institute of Food Science and Technology and Riddet Institute, Massey University, Private Bag 11, 222 Palmerston North 4442, New Zealand