a1 Institute of Food Hygiene, University of Leipzig, An der Tierkliniken 35, 04103 Leipzig, Germany
a2 Institute of Veterinary Food Science, Justus-Liebig University, Giessen, Frankfurter St 92, 35392 Giessen, Germany
a3 Institute of Biochemistry and Endocrinology, Justus-Liebig University, Giessen, Frankfurter St 100, 35392 Giessen, Germany
Correspondence:
c1 *Corresponding author: Dr E. Lücker, fax +49 341 97 3 82 49, email luecker@vmf.uni-leipzig.de