Which bedding for cattle was linked to a higher occurrence of coliform mastitis?

• A. Sawdust
• B. Sand
• C. Straw
• D. Wood shavings

Answer: (A)

Bedding quality and how it interacts with bacteria on the farm drive the risk of environmental coliform mastitis. Coliforms like E. coli and Klebsiella come from the environment and contaminate the teat ends when cows lie down, especially if the bedding is damp and rich in organic matter.

Sawdust tends to retain moisture and provide a plentiful surface for bacterial growth, including coliforms. Its fine particles can spread around the udder and teat ends, increasing the chance that these pathogens contact and invade teat tissue. That combination of moisture, organic material, and bedding contact makes sawdust more likely to be associated with higher rates of coliform mastitis.

By contrast, sand drains and dries quickly, supporting a cleaner, less bacterial environment, which generally translates to a lower risk. Straw and wood shavings can harbor bacteria too, but their risk is more variable and often lower than damp sawdust, depending on management, cleanliness, and moisture control.

So, the bedding that most strongly correlates with higher coliform mastitis is sawdust.