A study of the susceptibility of cattle to oral infection by salmonellas contained in raw sewage sludge.

Raw sewage sludge, containing up to 10(5) naturally occuring salmonellas/1, was included in the diet of one group of cattle at the rate 1 ]/animal/day and in a second group at the rate of 1 ]/animal/week. Sterilized sludge, to which had been added 10(5) S. dublin/litre, was included in the diet of a third group of animals at the rate of 1 ]/animal/day. Salmonellas were isolated from all samples of raw sewage sludge but were not isolated from the faeces or carcasses of animals fed on the sludge. Salmonellas were isolated from the faeces of one animal and the carcasses of two animals fed on sterilized sludge to which S. dublin had been added.