Campylobacter prevalence in Danish finisher pigs from mixed production herds

ORAL PRESENTATIONS these media are not appropriate for detection of non-motile or less motile Salmonella bacteria. Therefore, a combination of a semi-solid medium with a liquid medium, such as RV, is recommended. Several factors were significantly associated with the presence of Salmonella spp. The increased risk associated with natural ventilation might be related to biosecurity, which is likely to be lower in naturally ventilated barns. The decreased risk associated with an age of 2-3 months compared to an age of 3-4 months might be related to one or more causes, i.e. (i) maternal immunity preventing Salmonella colonisation at a younger age, (ii) a preventive effect of medication administered at an early stage of life, or (iii) enhanced exposure to Salmonella after transportation to a finishing barn (usually around 10 weeks of age). The protective effect found for the use of fermented liquid feed is hypothetically related to the presence of organic acids in this type of feed which may inhibit the presence of Salmonella in the feed and enhance the acid barrier of the stomach (van der Wolf et al., 2001). The preventive effect found for the presence of cats on the premise might be related to the expelling of rodents, which are considered important vectors for Salmonella infection (Lo Fo Wong et al., 2002). For the other associations determined, no hypotheses could be generated.