Abstract

Studies were carried out in 1991 on the efficacy of sterilisation processes at three rendering plants for dead animals and animal wastes in the Netherlands. Spores of sulfite reducing clostridia were detected in 4.8% of the samples taken directly after autoclaving. However, C.perfringens was not detected. Salmonella was detected in one sample (5%) of final products from plant C, and no Salmonella was detected in samples of final products from plants A and B. At plants A and C Salmonella was detected in 7.4% and 65.0% respectively of samples of dust taken from the processing halls. At plant B no dust samples were examined. In 93.5% of samples of final products the number of Enterobacteriaceae was less than 10 cfu per gram. Higher numbers of Enterobacteriaceae were detected incidentally in samples of final products from plants A and B and in dust samples from plant A, but frequently in dust samples from plant C. The results indicate poor hygienic conditions at plant C. This plant has been closed down in june 1991.