New work from Penn State University evaluates the effectiveness of calf milk pasteurization. Researchers measured bacteria counts in the milk before and after pasteurization and in the milk fed to calves to see just how effective pasteurization was.

Six different farms ranging in size from 500 to 2,000 cows participated in the study; none of which routinely monitored pasteurizer performance.

Results show that pasteurization can be an effective tool for reducing the number of bacteria in milk.

Researchers reported that for all of the bacteria counts measured, more samples met the goal after pasteurization than before and all counts were lower after pasteurization.

Despite the fact that bacteria levels after pasteurization were reduced, researchers found when they sampled milk from the calf buckets at feeding fewer samples met bacteria goals. All types of bacteria were higher in samples pulled from calf buckets than in pasteurized milk. Specifically for environmental staphylococci, bacteria counts in the samples taken from the buckets after pasteurization were as high as those in raw milk prior to pasteurization.

Study authors concluded that this is a good indicator that milk is frequently contaminated between pasteurization and feeding.

This research is discussed in depth in the December issue of the Penn State Dairy Digest. Read more.