These are mainly white blood cells (leucocytes), as well as epithelial cells. These are naturally present in the cow’s udder but can also develop in response to mastitis (inflammation of the udder), to fight infection. The somatic cell count is therefore an indicator of cattle health.

Germs are bacteria present in milk. There are few of them when the milk comes out of the udder, but they increase upon contact with ambient air and depending on storage conditions. That is why milk is kept refrigerated. The germ content of milk is an indicator of food safety.