The way in which the changing structure of dairy farming is affecting hygiene on the farm is considered. Increasing herd size and automation of milking equipment have resulted in larger milking plants, which in turn have led to higher rates of milking and more complex plants to be cleaned. The three main sources of contamination in ex‐farm milk, that is the udder, teat surfaces and milking equipment, remain but new aspects within these areas need to be considered. The importance of detecting clinical mastitis. preparing cows for milking, cleaning equipment and cooling milk is discusse