Individual cow somatic cell count (SCC) — the number of white blood cells per milliliter of milk — is the most widely available and welfare-informative measurement in dairy farming. Understanding how to interpret and use SCC data transforms routine milk recording from a production management tool into a welfare monitoring system.
Somatic cells are primarily neutrophils (white blood cells) that migrate into the udder in response to bacterial infection or physical damage. A cow with no udder infection typically has SCC below 100,000 cells/ml. As infection establishes and the immune response intensifies, SCC rises — sometimes to millions of cells/ml in severe cases. SCC elevation therefore directly indicates udder inflammation and immune system activation, both of which are associated with pain and welfare impairment.
Individual cow SCC interpretation: below 200,000 = low infection risk, good welfare; 200,000-400,000 = likely subclinical mastitis, welfare concern; above 400,000 = high probability of mastitis, welfare action required. Chronic elevation (multiple recordings above threshold) indicates persistent infection requiring veterinary assessment and treatment decision. Sudden rises in previously low-SCC cows indicate new infections requiring prompt investigation.
Monthly milk recording with individual SCC enables: identification of chronic subclinical cases, monitoring of treatment response, culling decisions for chronically infected cows, and assessment of overall herd udder health trends. Farms using SCC data proactively — not just reactively — show lower mastitis prevalence and better welfare outcomes. Automated in-line SCC monitoring (on robotic milking systems) provides real-time infection detection.
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