Endogenous opioids are involved in abnormal stereotyped behaviours of tethered sows

• Published in: Neuropeptides (Edinburgh) Vol. 6; no. 6; pp. 527 - 530
• Main Authors: Cronin, Gregory M., Wiepkema, Piet R., van Ree, Jan M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.1985; Elsevier
• Subjects: Animals; Behavioral psychophysiology; Biological and medical sciences; Endorphins - physiology; Female; Fundamental and applied biological sciences. Psychology; Naloxone - pharmacology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Restraint, Physical; Stereotyped Behavior - physiology; Swine; Exploratory behavior; Central nervous system; Opioid peptide; Stress; Pig; Vertebrata; Mammalia; Animal; Neurotransmitter; Environment; Female; Habitat; Artiodactyla; Coping; Endorphin; Stereotypy; Ungulata
• ISSN: 0143-4179; 1532-2785
• DOI: 10.1016/0143-4179(85)90114-3

Tethered sows continuously performed stereotypies during a substantial part of the day time. A single subcutaneous injection with naloxone significantly decreased the profound stereotypies, while explorative behaviours of pigs were not affected by naloxone. In addition a long-term effect of naloxone was noticed. It is suggested that performing the seemingly purposeless stereotypies may function as an effective strategy in order to cope with the conflict-inducing housing conditions. The present data implicate endorphins in this strategy. The involvement of endorphins in the stereotypies of the sows may be related to the calming, rewarding and dependency-inducing effects of the endorphins.