Leghorn hens, for example, are separated from their eggs as soon as they've been laid and have forgotten how to brood, a job that's been taken over by incubators.
例如產蛋用的來亨雞，為了不要它因孵蛋而停止產蛋，人們便留下不愛孵蛋的母雞為種雞，時至今日，來亨雞隻知下蛋，孵蛋的「天職」則交由「孵蛋器」包辦。