The effect of feeding pigs on food naturally contaminated with salmonellae

Abstract

1. The course of events following the feeding of salmonella-free pigs on food naturally contaminated with salmonellae has been followed. The pigs were killed at varying times after the commencement of the experiment and their organs examined for salmonellae. 2. None of the pigs showed any signs of ill-health and no pathological lesions were observed in them when they were killed. Salmonellae were found, however, in very small numbers in the mesenteric lymph nodes of some of them but not in any of their other internal organs or in their muscular tissue. The longer the pigs were fed on the contaminated food the more likely were their mesenteric lymph nodes to be infected. 3. Salmonellae were isolated from time to time from the faeces of the pigs but there was no suggestion of any of the pigs becoming permanent faecal excreters of these organisms. 4. Six pigs were retained for a short time after the use of the contaminated food was discontinued. Salmonellae were never found in their faeces and when they were killed the mesenteric lymph nodes of only one of them was found to be infected. 5. The results are discussed from the agricultural and public health viewpoints.