Which of the following describes how microbial contamination can occur during or after milking?

• A. Mastitis
• B. All of the above
• C. Feces on udder
• D. Contamination by humans or milking/processing equipment

Answer: (B)

Contamination can come from multiple sources that affect milk during milking or after. If the cow has mastitis, bacteria are present in the udder and can be shed into the milk, increasing the risk of contamination. Feces on the udder or contamination from fecal matter in the milking environment can introduce enteric bacteria into the milk. Likewise, microbes can be introduced by humans or by milking and processing equipment through inadequate hygiene or sanitation. Because each of these routes can contribute to contamination, the best description is all of the above. This underlines why effective mastitis control, udder hygiene, careful handling by personnel, and thorough sanitation of equipment and processing lines are essential to keep milk clean and safe.