Trends in quarter-level somatic cell count and implications for quarter milk separation

The sale of quarter-separated milk is prohibited under the Pas­teurized Milk Ordinance; all milk harvested from a cow with 1 or more abnormal quarters must be discarded. However, the milk produced by unaffected quarters may still be of acceptable quality, i.e. low somatic cell count (SCC). With the increasing popularity of automatic milking systems (AMS) and real-time udder-level SCC monitoring, milk quality must be investigated as future technology may allow for automated quarter-level testing and separation. This study sought to evaluate SCC trends in quarter-separated milk samples from cows with differing numbers of high SCC quarters, in order to determine if unaf­fected quarters continue to produce low SCC milk.