The development of intensive livestock production systems over the last forty or so years has resulted in large numbers of animals being looked after by relatively small numbers of stockmen. This widening of the animal: man ratio has been made possible by the increasing use of mechanical and electronic (computer) devices to maintain, manipulate and monitor these intensively kept animals. Nowadays it is possible to warm/ventilate and clean out animal houses by means of carefully engineered control systems; cows can be automatically milked; pigs can be permitted/refused access to a ‘help yourself’ feeding station according to the identification code held within their neck collar; poultry can have their body-weights regularly monitored and the stockman can be informed when the flock's weight gain deviates significantly from a preset norm. There are many potential production and welfare advantages to be gained from the use of these mechanical and electronic devices - there are also potential disadvantages, for example reduction in the stockman's contact with the individual animal, the danger of power cuts.