1. Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
2. Provincial Institute for the Prevention of Animal Diseases West-Vlaanderen, Industrielaan 29, B-8820 Torhout, Belgium
3. Vitamex NV, Booiebos 5, B-9031 Drongen, Belgium