[Behavioral disorders in animals of stock farms]

Intensively kept farm animals often show behavioural disturbances; some of these disturbances will cause pain (injurious behaviour), others will reflect pain (limping, colic). Also, the very common stereotypies are associated with pain. These stereotypies are characterized by their constant form and senseless repetitions. Stereotypies of tethered sows would appear to be specifically related with endorphins; they may act as agents promoting the release of endorphins and thereby calming the animal. This tranquilizing and protective function of stereotypies may play a role in veal calves showing abomasal injury. It was found that those calves that displayed most stereotypies had the least abomasal damage. Finally, a model is described, which makes it clear why emotions are essential in the behaviour of man and animals.