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Calcagnoli, F., Boer, S. F., Althaus, M., Boer, J. A., & Koolhaas, J. M. (2013). Antiaggressive activity of central oxytocin in male rats. Psychopharmacology, 229(4), 639–651.
Abstract: Rationale A substantial body of research suggests that the
neuropeptide oxytocin promotes social affiliative behaviors
in a wide range of animals including humans. However, its
antiaggressive action has not been unequivocally demonstrated
in male laboratory rodents.
Objective Our primary goal was to examine the putative
serenic effect of oxytocin in a feral strain (wild type
Groningen, WTG) of rats that generally show a much
broader variation and higher levels of intermale aggression
than commonly used laboratory strains of rats.
Methods Resident animals were intracerebroventricularly
(icv) administered with different doses of synthetic oxytocin
and oxytocin receptor antagonist, alone and in combination,
in order to manipulate brain oxytocin functioning and to
assess their behavioral response to an intruder.
Results Our data clearly demonstrate that acute icv administered
oxytocin produces dose-dependent and receptorselective
changes in social behavior, reducing aggression
and potentiating social exploration. These antiaggressive
effects are stronger in the more offensive rats. On the other
hand, administration of an oxytocin receptor antagonist
tends to increase (nonsignificantly) aggression only in
low–medium aggressive animals.
Conclusions These results suggest that transiently enhancing
brain oxytocin function has potent antiaggressive effects,
whereas its attenuation tends to enhance aggressiveness. In
addition, a possible inverse relationship between trait aggression
and endogenous oxytocinergic signaling is revealed.
Overall, this study emphasizes the importance of brain
oxytocinergic signaling for regulating intermale offensive aggression.
This study supports the suggestion that oxytocin
receptor agonists could clinically be useful for curbing heightened
aggression seen in a range of neuropsychiatric disorders
like antisocial personality disorder, autism, and addiction.
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Brinkmann, L., Gerken, M., & Riek, A. (2013). Effect of long-term feed restriction on the health status and welfare of a robust horse breed, the Shetland pony (Equus ferus caballus). Res. Vet. Sci., 94(3), 826–831.
Abstract: Outdoor group housing is increasingly recognized as an appropriate housing system for domesticated horses. The objective of this study was therefore to investigate the effect of potential feed shortage in semi-natural horse keeping systems in winter on animal health and welfare. In 10 female Shetland ponies blood concentrations (NEFA, total protein (TP), total bilirubin (TB), beta-hydroxybutyrate (BHB) and thyroxine (T4)), body mass and the body condition score (BCS) were monitored for 7months including a 4months period of feed restriction in five of the 10 ponies. Restrictively fed animals lost 18.4±2.99% of their body mass and the BCS decreased by 2.2±0.8 points (BCS scale: 0=emaciated, 5=obese). Feed restriction led to a continuous increase in TB (P<0.001) and NEFA (P<0.01) concentrations compared to control ponies. The TP and BHB values only differed at the end of the trial with lower concentrations in restricted fed mares (P<0.05). Feed restriction had no effect on thyroxine concentrations. TB concentrations in the feed restricted group were out of the reference range during the entire feeding trial. The increased NEFA concentrations in feed restricted compared to control ponies suggest that fat was mobilized. The BCS, as well as plasma NEFA and TB concentrations were good indicators for a rapid detection of possible health problems caused by undernourishment in horses when kept under semi-natural conditions. In contrast, blood parameters of the control animals were within the reference ranges, suggesting that a year round outdoor housing with additional feed supply is an adequate housing system for a robust horse breed like the Shetland pony.
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Briefer, E. F., & McElligott, A. G. (2013). Rescued goats at a sanctuary display positive mood after former neglect. Appl Anim Behav Sci, 146.
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Briefer Freymond, S., Briefer, E. F., Niederhäusern, R. V., & Bachmann, I. (2013). Pattern of Social Interactions after Group Integration: A Possibility to Keep Stallions in Group. PLoS ONE, 8(1), e54688 EP -.
Abstract: <p>Horses are often kept in individual stables, rather than in outdoor groups, despite such housing system fulfilling many of their welfare needs, such as the access to social partners. Keeping domestic stallions in outdoor groups would mimic bachelor bands that are found in the wild. Unfortunately, the high level of aggression that unfamiliar stallions display when they first <italic>encounter each other</italic> discourages owners from keeping them in groups. However, this level of aggression is likely to be particularly important only during group integration, when the dominance hierarchy is being established, whereas relatively low aggression rates have been observed among stable feral bachelor bands. We investigated the possibility of housing breeding stallions owned by the Swiss National Stud in groups on a large pasture (5 stallions in 2009 and 8 stallions in 2010). We studied the pattern of agonistic, ritual and affiliative interactions after group integration (17–23 days), and the factors influencing these interactions (time after group integration, dominance rank, age or experience of group housing). We found that stallions displayed generally more ritual than agonistic and than affiliative interactions. The frequency of agonistic and ritual interactions decreased quickly within the first three to four days. The frequency of affiliative interactions increased slowly with time before decreasing after 9–14 days. A stable hierarchy could be measured after 2–3 months. The highest-ranking males had less ritual interactions than the lowest-ranking. Males had also less agonistic, ritual and affiliative interactions if they had already been housed in a group the previous year. Therefore, we found that breeding stallions could be housed together on a large pasture, because the frequency of agonistic interactions decreased quickly and remained at a minimal level from the fourth day following group integration. This housing system could potentially increase horse welfare and reduce labour associated with horse management.</p>
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Beran, M. J., Smith, J. D., & Perdue, B. M. (2013). Language-Trained Chimpanzees (Pan troglodytes) Name What They Have Seen but Look First at What They Have Not Seen. Psychol Sci, .
Abstract: Metacognition can be defined as knowing what one knows, and the question of whether nonhuman animals are metacognitive has driven an intense debate. We tested 3 language-trained chimpanzees in an information-seeking task in which the identity of a food item was the critical piece of information needed to obtain the food. The chimpanzees could either report the identity of the food immediately or first check a container in which the food had been hidden. In two experiments, the chimpanzees were significantly more likely to visit the container first on trials in which they could not know its contents but were more likely to just name the food item without looking into the container on trials in which they had seen its contents. Thus, chimpanzees showed efficient information-seeking behavior that suggested they knew what they had or had not already seen when it was time to name a hidden item.
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Benz, B., Benitz, B., Krueger, K., & Winter, D. (2013). Weniger Einstreu bei gleichem Komfort. Pferdezucht und Haltung, 1, 66–71.
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Benson-Amram, S., Weldele, M. L., & Holekamp, K. E. (2013). A comparison of innovative problem-solving abilities between wild and captive spotted hyaenas, Crocuta crocuta. Animal Behaviour, 85(2), 349–356.
Abstract: Innovative problem solving enables individuals to deal with novel social and ecological challenges. However, our understanding of the importance of innovation for animals in their natural habitat is limited because experimental investigations of innovation have historically focused on captive animals. To determine how captivity affects innovation, and whether captive studies of animal innovation suffer from low external validity, we need experimental investigations of innovation in both wild and captive populations of the same species in diverse taxa. Here we inquired whether wild and captive spotted hyaenas differ in their ability to solve the same novel technical problem, and in the diversity of exploratory behaviours they exhibit when first interacting with the problem. Our results suggest that wild and captive populations show important differences in their innovative problem-solving abilities. Captive hyaenas were significantly more successful at solving the novel problem, and significantly more diverse in their initial exploratory behaviour, than were wild hyaenas. We were able to rule out hypotheses suggesting that these differences result from excess energy or time available to captive animals. We conclude that captive hyaenas were more successful because captive individuals were less neophobic and more exploratory than their wild counterparts. These results have important implications for our interpretation of studies on innovative problem solving in captive animals and aid our attempts to gain a broader understanding of the importance of innovation for animals in their natural habitat.
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Begall, S., Malkemper, E. P., Cervený, J., Nemec, P., & Burda, H. (2013). Magnetic alignment in mammals and other animals. Mamm. Biol., 78(1), 10–20.
Abstract: Magnetic alignment (MA) constitutes the simplest directional response to the geomagnetic field. In contrast to magnetic compass orientation, MA is not goal directed and represents a spontaneous, fixed directional response. Because animals tend to align their bodies along or perpendicular to the magnetic field lines, MA typically leads to bimodal or quadrimodal orientation, although there is also growing evidence for a fixed unimodal orientation not necessarily coinciding with the magnetic cardinal directions. MA has been demonstrated in diverse animals including insects, amphibians, fish, and mammals. Alignment can be expressed by animals during resting as well as on the move (e.g. while grazing, hunting, feeding, etc.). Here, we briefly survey characteristic features and classical examples of MA and review the current knowledge about the occurrence of MA in mammals. In addition, we summarize what is known about mechanisms underlying MA and discuss its prospective biological functions. Finally, we highlight some physiological effects of alignment along the magnetic field axes reported in humans. We argue that the phenomenon of MA adds a new paradigm that can be exploited for investigation of magnetoreception in mammals.
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Becker-Birck, M., Schmidt, A., Wulf, M., Aurich, J., von der Wense, A., Möstl, E., et al. (2013). Cortisol release, heart rate and heart rate variability, and superficial body temperature, in horses lunged either with hyperflexion of the neck or with an extended head and neck position. Journal of Animal Physiology and Animal Nutrition, 97(2), 322–330.
Abstract: Bringing the head and neck of ridden horses into a position of hyperflexion is widely used in equestrian sports. In our study, the hypothesis was tested that hyperflexion is an acute stressor for horses. Salivary cortisol concentrations, heart rate, heart rate variability (HRV) and superficial body temperature were determined in horses (n = 16) lunged on two subsequent days. The head and neck of the horse was fixed with side reins in a position allowing forward extension on day A and fixed in hyperflexion on day B. The order of treatments alternated between horses. In response to lunging, cortisol concentration increased (day A from 0.73 ± 0.06 to 1.41 ± 0.13 ng/ml, p < 0.001; day B from 0.68 ± 0.07 to 1.38 ± 0.13 ng/ml, p < 0.001) but did not differ between days A and B. Beat-to-beat (RR) interval decreased in response to lunging on both days. HRV variables standard deviation of RR interval (SDRR) and RMSSD (root mean square of successive RR differences) decreased (p < 0.001) but did not differ between days. In the cranial region of the neck, the difference between maximum and minimum temperature was increased in hyperflexion (p < 0.01). In conclusion, physiological parameters do not indicate an acute stress response to hyperflexion of the head alone in horses lunged at moderate speed and not touched with the whip. However, if hyperflexion is combined with active intervention of a rider, a stressful experience for the horse cannot be excluded.
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Baciadonna, L., McElligott, A. G., & Briefer, E. F. (2013). Goats favour personal over social information in an experimental foraging task. Peer J, 1.
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