1. Laboratory of Poultry Sciences, Faculty of Sciences, University of Lome, B.P. 1515 Lome, Togo
2. Laboratory of Pharmacology of Natural Substances, Faculty of Sciences, University of Lome, B.P. 1515 Lome, Togo
3. Laboratory for Physiology, Immunology and Genetics of Domestic Animals, Department of Biosystems, K.U. Leuven, Belgium