If you use an on-farm pasteurizer, it’s important to keep in mind that pasteurization does not equal sterilization.

Research by Bob James, professor of dairy science and extension dairy nutritionist at Virginia Tech, has shown that a significant number of dairies using an on-farm pasteurizer had high bacteria counts both before and after pasteurization.

The Standard Plate Count (SPC) of pasteurized milk should be less than 20,000 cfu/mL

James’ data show SPC as high as 5,000,000 before pasteurization; after pasteurization, counts were over 1,000,000 when pasteurizers were not operating correctly and 300,000 to 17,000,000 by the time the last calf was fed.