Cows should be milked twice a day, seven days a week at regular times, and in a calm environment. The repetitive gesture, whether manual or mechanical, allows the extraction of milk from the animal's udder. Milking machines are vacuum pumps that produce a suction similar to the one exerted by calves. Standard or rotary models, such as those used at La Grange de la Haute Vallée, still require human intervention. They differ from more modern milking robots that allow total automation of the operation.