A simple rope tied to the fence may someday help you identify the prevalence of E. coli O157:H7 in feedlot cattle. University of Nebraska animal scientists have received a $950,000 grant to develop better ways to measure E. coli in pens of cattle and to identify control strategies. And the rope test is at the heart of the ongoing research.

Capitalizing on cattle’s natural propensity to chew and lick everything in sight, researchers found that over half the cattle in a pen will chew pieces of rope hung around the pen within two hours. And when they chew the rope they deposit traces of the organisms they’re carrying. Researchers remove the ropes and conduct specialized tests to determine the prevalence of E. coli in that pen.

The rope test grew from Nebraska’s ongoing on-farm animal production food safety research aimed at controlling E. coli on farms, ranches and feedlots—to keep it from reaching processing plants. From the start, scientists recognized the need for a simple way to test pens of cattle without handling individual animals, which is expensive and impractical.

After trying high- and low-tech possibilities, the Nebraska researchers found the simple test was most effective. Previous work 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 the high-prevalence pens plus medium-prevalence pens where at least 16 percent of cattle are shedding the bacteria.

The next phase of research involves using the rope test to more extensively compare conditions in high-, medium- and low-prevalence pens and to determine environmental or management differences. Researchers aim to identify potential E. coli risk factors such as time on feed, temperatures and pen conditions. Eventually, they’ll use the test to evaluate the effectiveness of control strategies designed to address these risks.

The rope test was devised as a research tool, but eventually could help producers match E. coli intervention strategies to specific pens of cattle. The test hasn’t been commercialized.