title: Effects of Oxytocin Administration on the Response of Piglets to Weaning.
abstract: Weaning is often an abrupt and stressful process. We studied the effects of administering oxytocin, subcutaneously or intranasally, on the ability of pigs to cope with weaning. On a commercial farm 144, 30 day-old pigs from 24 litters were used. On the day of weaning, one male and one female in each litter were administered one of three treatments: intranasal oxytocin (24 International Unit), subcutaneous oxytocin (10 International Unit per kg of body weight), or handled as a control. The pigs were placed in one of eight weaner pens, split by sex and with an equal representation of treatments. Data included body weight and growth, physiology (neutrophil:lymphocyte ratio, plasma cortisol, C-reactive protein and Tumor Necrosis Factor-α concentrations), and behavior (feeding, drinking, social behavior). Both oxytocin treatments tended to result in higher levels of mild aggression within groups (p = 0.08), specifically between oxytocin-administered and control pigs (subcutaneous to control p = 0.03; intranasal to control p = 0.10). Subcutaneously-administered pigs tended to frequent the feeder more often than intranasally-administered pigs (p < 0.10), with the latter having slightly lower body weight 38 days post-weaning (p = 0.03). However, acute oxytocin administration did not result in any noticeable physiological changes 4 or 28 h post-weaning. Hence, the use of a single administration of oxytocin prior to weaning in pigs is not recommended, at least not in the conditions studied here.
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3010, Australia. raultj@unimelb.edu.au.
authors.forename: Jean-Loup
authors.initials: JL
authors.lastname: Rault
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3010, Australia. fdunshea@unimelb.edu.au.
authors.forename: Frank R
authors.initials: FR
authors.lastname: Dunshea
authors.affiliation: School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150, Australia. j.pluske@murdoch.edu.au.
authors.forename: John R
authors.initials: JR
authors.lastname: Pluske
keywords: behavior; intranasal; oxytocin; physiology; stress; subcutaneous; sus scrofa