1. ; Animal Science Department, Nutritional Biochemistry Division; University of Ibadan; Nigeria
2. ; Department of Biochemistry and Physiology of Nutrition; German Institute of Human Nutrition; Bergholz-Rehbrücke D-14558 Germany
3. ; Deutsches Institut für Ernährungsforschung; Arthur-Scheunert-Allee 114-116 Bergholz-Rehbrücke D-14558 Germany