ORAL PRESENTATIONS ORAL PRESENTATIONS

In a cross-sectional study, the impact of ‘animal-friendly ’ housing systems on the prevalence of Salmonella species, Campylobacter species, and Yersinia enterocolitica in finishing pigs and pork was investigated. Furthermore, antimicrobial resistance patterns of isolated campylobacter strains were analysed. In faecal samples of two out of 88 fattening pig farms salmonellae were isolated. All 865 samples of pork were found to be negative. Campylobacter was isolated on 98.9 % of the farms but only from 0.2 % of the pork samples. Yersiniae were found in samples of 63.3 % of the farms and in 15.4 % of pork samples. For all three bacteria, there was no statistically significant difference in the prevalence between conventional and ‘animal-friendly ’ housing systems. In ‘animal-friendly ’ farms, antimicrobial resistance of campylobacter isolates to fluoroquinolones and streptomycin was significantly less frequent than in conventional farms. Furthermore, fewer isolates had resistance to three or more antimicrobials in ‘animal-friendly ’ farms. Introduction: ‘Animal-friendly ’ production systems for finishing pigs are promoted by the Swiss Federal Office for Agriculture. Such systems primarily differ from conventional production in the use of straw bedding and outdoor access. In 2000, 28 % of Swiss fattening pigs were kept in farms with ‘animal-friendly ’ production systems (Anonym, 2002). It was shown that these systems improve pig welfar