1. Division of Comparative Biomedical Sciences, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Italy
2. Animal Production and Health Laboratory, Joint FAO/IAEA Division for Nuclear Applications in Food and Agriculture, International Atomic Energy Agency, Seibersdorf, Austria
3. Division of Avian Diseases, Kimron Veterinary Institute, Bet Dagan, Israel