Cow udder infections are rarely the source of bacteria that result in elevated, bulktank milk bacteria counts. Even if elevated somatic-cell counts are prevalent among cows in a herd, or the incidence of mastitis in a given time period is high, the number of bacteria shed by infected quarters of the udder is low, compared to numbers that are of concern in cases of elevated bulk tank milk bacteria counts.
Additionally, the duration of high rates of bacterial shedding from udder infections is short.Addressing issues related to milking equipment hygiene usually reduces elevated bacterial counts in bulk milk. In conventional terms, this means improving the cleaning of milking and milk storage equipment, remedying deficiencies in cooling so that milk is cooled appropriately to below 4 °C after every milking, and maintaining milk at that temperature during farm storage and transport to the processing plant. Occasionally, however, udder infections can affect milk quality.