Why must ground meats be cooked to a higher temperature than whole cuts of meat?

The outside of meat contains more pathogens than the inside. This is because it comes into contact with more surfaces and is more likely to be exposed to conditions that encourage pathogens to multiply. When whole cuts of meat are cooked, the outside of the meat receives the most intense heat. This will ensure that the pathogens on the outside are killed. When meats are ground, the outside of the meat blends throughout the meat. For this reason, ground meat should be cooked to a higher internal temperature than whole cuts of meat. Another reason that ground meat should be cooked to a higher temperature is that it contains more animals. A beef roast contains the meat from one cow. Ground beef could contain the meat from dozens of cattle. If the meat from one sick cow is ground together with 20 healthy cows, the risk is spread to more people. A higher cooking temperature is an extra precaution for this risk.