vocabularies

How a poultry feeder or drinker presents its ration (feed or drinking water) to the birds — the access-station structure the animal actually eats or drinks from: a gravity feed pan (a jar or tube hopper discharging into a surrounding open pan or ring), an open feed tray (a flat open tray with no reservoir), a vacuum water trough (an inverted reservoir held by vacuum, metering into a surrounding drinking trough), or a water nipple (a pecked valve releasing water on demand). A token category; its members are VALUES of the poultry feeder/drinker kind, not separate classes — a jar feeder, a tube feeder, a bell drinker and a nipple drinker differ by this port plus capacity. A growing vocabulary (L13): a drinking cup, a treadle-covered feed hopper, an open linear trough are added as real SKUs are seeded.

Answers the question: feeding port.