[1] Univ Ghent, Fac Vet Med, Dept Pharmacol Toxicol & Biochem, Salisburylaan 133, B-9820 Merelbeke, Belgium
[2] Univ Ghent, Fac Vet Med, Dept Pathol Bacteriol & Avian Dis, Salisburylaan 133, B-9820 Merelbeke, Belgium
[3] Biomin Res Ctr, Technopk 1, A-3430 Tulln, Austria