I t is common for milk in certain production areas to spend two days in the farm tank and additional time in the processor's tank before being pasteurized. If it is contaminated with these cold tolerant bacteria they may produce various enzymes that can lead to off-flavors. These bacteria are killed by pasteurization but the enzymes produced by them may survive and continue to cause damage to the milk fat and protein and this is the concern. W hen PI counts are a problem it requires a thorough review of many possible contributing factors. These cold tolerant bacteria do not normally originate from infections of the gland but there may be exceptions.
All factors have to be evaluated thoroughly.
Examine carefully all tubing and milk contact surfaces. They may be worn and cracks or crevices may allow milk soils to be deposited, offering growth opportunities for these bacteria. Make certain cows are being thoroughly cleaned and are dry prior to units being attached. Water is sometimes a source of bacteria which may elevate the PI count. Minimize water use and be certain to dry the udder and teats thoroughly prior to unit attachment.