The Importance of SCC

14 Mar 2016

Somatic cell count (SCC) data can be used as a good indication of health in both individual cow as well as the herd.

SCC monitoring is important because as the number of somatic cells increases, milk production yields decline, mainly due to damage to the tissue in the udder caused by pathogens and the toxins they produce. With a risk of loss of production, cost of treatment or replacement and missed premiums, SCC monitoring should be an integral part of your herd management.

The question is, “what exactly can we see in the numbers?” It’s important to keep track of the counts for individual cows and the aggregate SCC from strings or bulk tanks. We know as the SCC increases over 200,000 cells/ml it suggests that there could be a subclinical issue. On the other scale, a very low SCC could indicate the cow is not producing enough white blood cells to provide protection against bacterial infection, therefore it is susceptible to clinical mastitis. But this argument does not always hold true. There is a need to look at the numbers as a management tool.

As you begin to accumulate an SCC history of your herd, you will be able to pay attention to trends which will aid in reacting to treatments:


Increase / Decrease SCC

Additional Information

Bacteria infection


Increase depends on severity of infection



May increase depending on factor


Increase after calving

Will come down after five days if the cow was healthy before

Duration between milking


May increase with shorter intervals (stress)

Bulk tank SCC


Will fluctuate more with smaller herds, less with dilution

Sample to sample


Sampling will fluctuate results

Sample methods


Bad techniques can alter results

Note: It is important to collect, store, and analyze milk samples in an appropriate manner. Sampling at the very beginning or end will have an increased concentration of cells. It is advised to strip the cow a few times prior to taken a sample if not milking. Samples taken away from the wall and top of the storage container is recommended as proteins and cells tend to aggregate in these areas.