Capitalizing on cattle's natural propensity to chew and lick everything in sight, they hang pieces of rope around a pen in the evening. Ropes are removed and specialized tests at the NU's Veterinary Diagnostic Center determine E. coli's prevalence in that pen. Previous studies showed rope tests are more sensitive than manure samples. Manure samples accurately identify only high prevalence pens where more than 40 percent of cattle are shedding E. coli. Rope tests detect these pens plus medium prevalence pens where at least 16 percent of cattle are shedding the bacteria.
Researchers classify pens as high, medium or low prevalence.
IANR scientists used rope tests as their main sampling tool for the first time in a feedlot study this summer. The rope test allowed researchers to test pens weekly and follow cattle throughout their feedlot period. This study is now wrapping up. Results will be available this winter. The next phase of research involves using the test to more extensively compare conditions in high, medium and low prevalence pens and to determine environmental or management differences.