STUDIES INTO THE OCCURRENCE OF SALMONELLA FOUND IN SLAUGHTER PIGS DECLARED FIT FOR HUMAN CONSUMPTION

From 1992 to 1996, 4,242 slaughter pigs of mainly German origin, which were declared clinically healthy and fit for human consumption, were tested for Salmonella in six studies comprising three slaughter plants located in different federal states. The following sample material - in varying degrees - was part of the test: swab samples of faeces, mus culature, liver, mesenteric lymph nodes and swab samples of the abdomi nal cavity. The samples were taken directly at the slaughter line and examined in the laboratory within the following two hours. The animals of German origin yielded a Salmonella detection rate of 1.7% on avera ge. In terms of food hygiene this is a rate which can be considered re latively low. However, this rate should not be underestimated because there were considerable differences among the individual suppliers. An imals infected with Salmonella were found at 27% of the pig farms test ed, with some farms displaying a rate of detection as high as 65%. Whe n not identified, quantities evidencing contamination to such an exten t are a high risk for the consumer. Detection rates above average were also found in animals of foreign origin which had been in transit for a long time. Here, the reason for the animals' infection can be due t o both the contamination at the farms of origin as well as transport s tress. Four out of the six studies conducted revealed Salmonella even in the depth of musculature, most probably as a consequence of endogen ic contamination. It is such cases in particular which make it necessa ry that core temperatures are reached as quickly as possible. Without making a claim for generalisation the results show on the one hand tha t - given the existing agricultural structure - pig production which i s free of Salmonella is feasible. On the other hand it is necessary fo r reasons of consumer protection and competition that programmes be im plemented that restrain the occurrence of Salmonella. That, however, w ill take a comprehensive assessment of the spread of Salmonella in fat tening pig stocks, an assessment which is not available for Germany ye t.