1. Departamento de Fisiología (Fisiología Animal), Complutense University of Madrid, Madrid, Spain;
2. Departmento de Producción Animal, Complutense University of Madrid, Madrid, Spain;
3. Department of Animal Production (Animal Physiology), Agriculture College, Cairo University, Giza, Egypt;
4. Departamento de Producción Agraria, Agricultural Engineering School, Polytechnic University of Madrid, Ciudad Universitaria, Madrid, Spain;
5. Departamento de Bioquímica IV y Biología Molecular, Complutense University of Madrid, Madrid, Spain;
6. Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Perugia University, Perugia, Italy