Studies worldwide have found E. coli O157:H7 shedding by grass-fed cattle relative to grain-fed cattle to be generally:

• A. considerably more
• B. about the same
• C. considerably less
• D. absent

Answer: (B)

The main idea is that diet alone does not reliably change how much E. coli O157:H7 cattle shed on a global scale. Across many countries and production settings, grass-fed and grain-fed cattle tend to shed the bacteria at similar rates. This reflects that shedding is influenced by a mix of factors—age, stress, transport, season, herd management, environmental exposure, and overall health—more than by whether cattle are fed grass or grain. While diet can alter the gut environment in theory, the worldwide data don’t show a consistent, meaningful difference between the two feeding systems. So, in terms of public health risk, grass-fed does not inherently offer lower or higher shedding compared with grain-fed; the risk is similar and should be managed through general controls across production stages, carcass handling, and cooking.