1. Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
2. Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang 330045, China
3. Dipartimento di Scienze e Tecnologie per l'Ambiente e il Territorio, Facoltà di Scienze Matematiche, Fisiche e Naturali, Università del Molise, 86090 Pesche, Italy
4. Division of Livestock, National Institute of Subtropical Agriculture, R.D.A., 175-6, O-Deung Dong, Jeju, 690-150, South Korea
5. Facultad de Ciencias Agroalimentarias, Universidad de Costa Rica, San Pedro, Costa Rica
6. Universidad Autónoma de Nayarit, 63155 Tepic, Mexico
7. Department of Animal Science, University of Zimbabwe, MP167, Mount Pleasant, Harare, Zimbabwe and
8. Institut Català de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain