The survival of Escherichia coli O157:H7 in slurry from cattle fed different diets

Aims: The survival characteristics of Escherichia Coli O157:H7 were investigated in bovine slurry from cattle fed two different diets: (i) silage and (ii) silage + concentrates. Methods and Results: Slurry samples collected from freshly-agitated tanks were inoculated at a level of log(10) 6.0 cfu g(-1) and stored in the laboratory at 10 degreesC. Over a 12 week storage period, a 3.5 and 5.5 log reduction was observed in slurry from cattle fed a silage and silage plus concentrate diet, respectively. Conclusions: The persistence of E. coli O157:H7 in slurry over a 3 month storage period indicates its potential for transmitting the organism back into the environment. Singificance and Impact of the Study: The discussion concludes however, that despite pathogen survival in slurry, it may not represent a major source of transmission in the farm environment.