THE total bacterial count (TBC) of bulk milk is an important measure of milk quality. Since 1982, dairy farmers have been paid a bonus for milk containing less than 20,000 bacteria per ml. In 1996, cultural methods of examination were replaced by an automated methodology, Bactoscan, which is based on staining live bacteria and counting particle numbers. It has the advantages of being cheaper, with a faster throughput and more rapid result. It also gives a higher value than standard cultural methods, since not all organisms grow on basic media. However, cultural examination of milk can still yield useful information and, by using differential culture methods, possible causes of a high TBC, high cell count or even a high mastitis incidence can be investigated. This article describes the techniques used and some of the results obtained by a practice laboratory.