Herve Tchoffo, Doctor/PhD. Animal Physiology and Health Research Unit, Department of Animal Production, Faculty of Agronomy and Agricultural Sciences (FASA), University of Dschang (UDs).P.O. Box 188 Dschang-Cameroon. Tel: +237 676656710, +237 693751195. E-mail : tchoffo.herv@yahoo.fr, herve.tchoffo@univ-dschang.org