Does milk contain blood and pus?

Regular milk does not contain blood or pus. Blood and pus may be present in the milk when the cow’s udder is infected with bacteria (mastitis) but this milk is discarded by the farmer and is not sent to the factory.

Last updated 30/04/2021

Dairy farmers monitor their cows at every milking for signs of mastitis or other conditions that could affect the quality of the milk. Abnormal milk from cows is collected into a separate vessel or bucket and discarded.

Before milk enters the milk collection vat it also passes through a filter which removes any undetected and unwanted material such as milk clots or organic material.

A sensory test is then undertaken before the milk goes into the milk tanker to detect any discolouration, odour or foreign material and the milk is rejected if it fails this test.

At the factory the milk is further filtered and subjected to a number of tests to assess its quality. The Bulk Milk Cell Count is performed on every farmers’ vat, which tests the number of white blood cells present in the milk, indicating mastitis. Regular tests are also conducted to detect bacteria and bacterial cells which is a measure of the milking plant hygiene, milk cooling efficiency and milking cleanliness. Farmers receive reduced payments if these tests are above an acceptable level, so they always strive to produce high quality milk.

All Australian dairy farmers must have an approved food safety program in place to meet state dairy authority requirements and this is a condition of supply to their milk factory. Farms are audited every one to two years (depending on the state) for compliance to their food safety program. Dairy factories also provide their suppliers with support staff to ensure they meet these important food safety and quality requirements, which includes the absence of blood and pus in milk.

Independent body Dairy Food Safety Victoria regulate on-farm food safety in Victoria, where most milk is produced. More information on food safety regulation can be found here.

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