ABSTRACT
Fris and Van den Bos (1995) reported that the Dutch poultry industry has attempted to prevent vertical transmission of Salmonella from breeders to broilers using a top-down approach with particular emphasis on controlling Salmonella serotype Enteritidis (SE). However, the efficacy of this program is now affected by
the increasing role of horizontal transmission, with biosecurity on the poultry farm gaining importance (Fris and Van den Bos, 1995). To assess the actual level of preventive hygiene and to identify risk factors involved, an inquiry was held among a representative number of broiler breeder farms. From these inquiries, it became evident that the hygiene conditions on Dutch broiler breeder farms can and must be improved (Fris and Van den Bos, 1995). From a matched case-control study carried out among SE-infected and SE-free farms, the occurrence of SE infection could be explained for about 30% by factors concerning preventive hygiene, the surroundings of the farm, and the farm itself. ’us, other factors, not included in the study, may also be important. No particular key factors were found. Preventive hygiene can certainly reduce the infection risk, but only a comprehensive package of measures can do so. Fris and Van den Bos (1995) concluded that the Dutch Product Board for Poultry and Eggs and the Dutch Organization of Poultry Farmers have now agreed to strict biosecurity programs to control horizontal transmission of SE, but these will require considerable technical and financial investments.
