Behavioral responses of periparturient sows and juvenile pigs to prostaglandin F2 alpha.
Within minutes after prostaglandin F2 alpha (PGF2 alpha) injection on d 112 postcoitum and again in the last few hours before delivery of the first piglet around 22 h later, sows in pens intensely rooted and pawed, which is typical prepartum nestbuilding behavior. Control sows engaged in most such typical prepartum activity (TPA) within 16 h before delivery. The overall frequencies and durations of TPA for the 48-h prepartum period were not influenced by injection, but injection of PGF2 alpha did alter the temporal pattern of behavior and resulted in a bimodal profile of activity. The PGF2 alpha injected 24 h postpartum immediately induced TPA in sows, but it was less intense and shorter than prepartum TPA. Postpartum only, some PGF2 alpha sows rubbed or kicked at their abdomens and seemed to experience discomfort. Because PGF2 alpha elicited TPA both pre- and postpartum, TPA probably was not directly triggered by changes in plasma progesterone concentration or in the estrogen:progesterone ratio. After injection of .5 or 1 mg PGF2 alpha, prepubertal pigs (approximately 10 kg) lay more but also changed posture more often. After PGF2 alpha, slight or no TPA was seen, but pigs pawed more often, showed signs of abdominal discomfort, defecated more often, stretched and arched their backs and scratched or kicked at their sides or abdomens. Most PGF2 alpha-induced TPA by prepartum sows probably is not caused by some general peripheral effect, but rather by some neural or endocrine change that stimulates nestbuilding specifically in animals primed by the endogenous endocrine environment of late pregnancy.
Widowski
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Anim. Sci. Dept., University of Illinois, Urbana 61801.
Curtis
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D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D015237:Dinoprost / Q000494:pharmacology*; D005260:Female; D007743:Labor, Obstetric / Q000187:drug effects; D008297:Male; D008425:Maternal Behavior; D049590:Postpartum Period / Q000187:drug effects; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000187:drug effects* / Q000502:physiology; D013552:Swine / Q000502:physiology*; D014741:Video Recording
D015237:Dinoprost