E. coli O157, salmonella prevalence on U.S. dairy operations examined

A study conducted by the US Department of Agriculture revealed the widespread occurrence of salmonella and Escherichia coli O157 on US dairy operations. The 1996 study by the US Department of Agriculture National Animal Health Monitoring System Dairy showed that 24.2% of 91 dairy operations and 30.9% of 97 cull dairy cow markets studied had at least one culture-positive cow. Almost 1% of the 3,600 milk cows analyzed were found to be shedding E. coli O157.