Wiepkema P R
Tijdschr Diergeneeskd. 1985 Jan 1;110(1):12-20.
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.
集约化饲养的农场动物常常表现出行为紊乱；其中一些紊乱会导致疼痛（伤害性行为），另一些则反映出疼痛（跛行、绞痛）。此外，非常常见的刻板行为也与疼痛有关。这些刻板行为的特点是形式固定且无意义地重复。拴系母猪的刻板行为似乎与内啡肽有特定关系；它们可能作为促进内啡肽释放的因子，从而使动物平静下来。刻板行为的这种镇静和保护功能可能在患有皱胃损伤的犊牛中起作用。研究发现，表现出最多刻板行为的犊牛皱胃损伤最小。最后，描述了一个模型，该模型阐明了为什么情感在人类和动物的行为中至关重要。
