Browsing by Author "Wahlfors, Maria"

Bovine and pig carcass surface hygiene is monitored in Finnish slaughter houses by taking samples at the end of the slaughter line before carcass chilling. The sampling methods and frequency are determined by the law. There are two approved sampling methods; swabbing and the destructive method. Samples are examined for aerobic bacterial counts and for enterobacterial or Escherichia coli bacterial counts. The sampling results used in this study were from ten Finnish slaughter houses. In the experimental part of this study there were taken surface hygiene samples from ten pig carcasses and ten bovine carcasses with both sampling methods. The destructive method generally reveals more bacteria than the swabbing method. The main problems of the swabbing method are the great variation and poor repeatability of the results and the influence of the sample taker. However, the swabbing method makes it possible to examine a larger area than it is reasonable to examine with the destructive method without causing too much damage to the carcass. Because of the non-uniform distribution of faecal bacteria on the carcass surface the swabbing method often reveals more enterobacteria / E. coli compared to the destructive method. Average total aerobic bacterial recoveries with swabbing, expressed as a percentage of the recoveries achieved by excision, varied widely (1-100%) in different studies. The general level of the surface hygiene of bovine and pig carcasses in Finnish slaughter houses does not essentially differ from the general European level. The average aerobic bacterial count of the whole year (2002-2003) for pig carcasses in slaughter houses using swabbing method (n=3) was 3,04 log10 cfu/cm2 and for those using destructive method (n=4) 3,03 log10 cfu/cm2. The corresponding numbers for bovine carcasses in Finnish slaughter houses were 2,44 log10 cfu/cm2 (swabbing, n=3) and 3,40 log10 cfu/cm2 (destructive, n=4). The average counts of different slaughter houses are defined as "satisfactory" according to the limits in the European Union law, with the exception of two bovine and one pig slaughter houses, the counts of which were "acceptable". The general level of enterobacteria or E.coli was also good, although there were occasional higher weekly counts in almost every slaughter plant. In the experimental part comparing the two sampling methods the destructive method generally revealed more aerobic bacteria compared to the swabbing method, but swabbing produced more enterobacteria positive sample results than the destructive method.