A SURVEY OF THE INCIDENCE OF SALMONELLA SPECIES AND ENTEROBACTERIACEAE IN POULTRY FEEDS AND FEED COMPONENTS

Between July 1990 and April 1991 the rate of contamination with Salmon ella species of poultry feeds and feed components used by the Dutch fe ed industry was surveyed. Ten per cent of 360, 10 g samples of poultry feeds were found to be contaminated. Mash feeds, mostly used for laye r-breeders, were far more frequently (21 per cent) contaminated than p elleted feeds (1.4 per cent). The rate of contamination of 130 samples of fish meal was 31 per cent, of 83 samples of meat and bone meal 4 p er cent, 58; samples of tapioca 2 per cent and of 15 samples of maize grits 27 per cent. Twenty-eight serotypes of salmonellae were isolated , but no Salmonella enteritidis was found, despite the occurrence of a n epidemic in poultry caused I by this serotype since 1987. The seroty pes isolated most frequently mere not the same as those encountered in poultry flocks. The Enterobacteriaceae isolated from the feedstuffs w ere predominantly, thermotrophic. They were shown to be useful markers of the rate of contamination with salmonellae and of the efficiency o f decontamination of the feedstuffs by pelletisation.