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Schneider, A. - C., Melis, A. P., & Tomasello, M. (2012). How chimpanzees solve collective action problems. Proceedings of the Royal Society B: Biological Sciences, .
Abstract: We presented small groups of chimpanzees with two collective action situations, in which action was necessary for reward but there was a disincentive for individuals to act owing to the possibility of free-riding on the efforts of others. We found that in simpler scenarios (experiment 1) in which group size was small, there was a positive relationship between rank and action with more dominant individuals volunteering to act more often, particularly when the reward was less dispersed. Social tolerance also seemed to mediate action whereby higher tolerance levels within a group resulted in individuals of lower ranks sometimes acting and appropriating more of the reward. In more complex scenarios, when group size was larger and cooperation was necessary (experiment 2), overcoming the problem was more challenging. There was highly significant variability in the action rates of different individuals as well as between dyads, suggesting success was more greatly influenced by the individual personalities and personal relationships present in the group.
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Schnerr, C. U. (2011). Feldstudie zur Epidemiologie und Bekämpfung von Strongyliden in Pferdebeständen im Raum Baden- Württemberg. Ph.D. thesis, , .
Abstract: In der Zeit von April 2005 bis März 2006 wurden bei 105 Pferden monatlich
koprologische Untersuchungen durchgeführt. Die Pferde waren zu zwei Drittel
Jungtiere (≤ 4 Jahre) und ein Drittel > 4 Jahre. Die zur Verfügung stehenden vier
Betriebe befanden sich alle im Raum Baden-Württemberg.
Die Kotproben wurden mit Hilfe der Flotation auf Magen-Darmnematoden untersucht
und anschließend einer quantitativen Eizahlbestimmung nach Mc Master unterzogen.
Ab einem Eigehalt von 250 Eiern pro Gramm Kot (EpG) wurden die Pferde
entsprechend der Gruppenzugehörigkeit entweder mit Pyrantel oder Ivermectin
behandelt.
Es wurden bei 73 Pferden ausschließlich Strongylideneier nachgewiesen; bei vier
Pferden waren in der Flotation zusätzlich Eier von Parascaris equorum zu finden.
Bei 28 (26,7%) der untersuchten Pferde wurden in keiner der 12 untersuchten
Proben Eier von Magen-Darmnematoden nachgewiesen. Insgesamt mussten
57 (54,3%) der Pferde über den gesamten Untersuchungszeitraum hinweg nicht
behandelt werden. 48 (45,7%) Pferde mussten mindestens einmal anthelminthisch
behandelt werden. Kein Pferd musste häufiger als dreimal behandelt werden.
In den Monaten August bis November war der Anteil an positiven Proben der
Jungtiere signifikant höher als bei den Pferden > 4 Jahre. Innerhalb der
Jungtiergruppe nahm die Höhe der Strongyliden-Eiausscheidung mit zunehmendem
Alter signifikant ab.
Ebenso nahm die Anzahl der positiven Proben im Laufe des
Untersuchungszeitraums signifikant ab.
Die beiden zur Entwurmung eingesetzten Substanzen (Pyrantel und Ivermectin)
waren voll wirksam. In 98,8% der untersuchten Proben war ein Rückgang der
Ei-Ausscheidung noch vier Wochen nach der Behandlung auf 0 EpG nachweisbar,
d. h. es gab keinerlei Anzeichen für das Vorliegen von Resistenzen gegen die
eingesetzten Substanzen.
Die vorliegenden Untersuchungen sind ein weiterer Beweis dafür, dass mit Hilfe der
selektiven anthelminthischen Behandlung die Anzahl der Entwurmungen –
insbesondere auch bei Jungtieren – deutlich gesenkt werden kann.
Die Eiausscheidung und damit die Weidekontamination werden mit Hilfe dieses
Verfahrens deutlich reduziert.
[Between April 2005 and March 2006 monthly koprological examinations where
carried out on 105 horses.
Two third of the horses were young animals (≤ 4 years) and a third were > 4 years
old.
The four farms on hand were all located in the Baden- Württemberg area.
Faecal samples were examined for gastro-intestinal nematodes by means of flotation
and subsequently subjected to an egg-quantity counting according to Mc Master.
Starting from an egg content of 250 eggs per gram faeces (EpG), the horses were
treated with either Pyrantel or Ivermectin according to their group affiliation.
In 73 horses solely Strongyle eggs were detected; the flotation of four horses
additionaly showed eggs of Parascaris equorum.
In 28 (26,7%) of the examined horses none of the 12 examined samples showed
eggs of gastro-intestinal nematodes.
Overall 57 (54,3%) horses didn´t need any treatment during the total examination
cycle. 48 (45,7%) of the horses needed at least one anthelminthic treatment.
None of the horses needed to be treated more than three times.
From August to November the rate of positive samples within the group of young
animals was significantly higher than in the horses > 4 years.
Whithin the group of young animals the level of Strongyle egg excretions dropped
significantly with advancing age.
Likewise, the number of positive samples also dropped significantly in the course of
the examination cycle.
Both substances (Pyrantel and Ivermectin) applied for deworming were fully effective.
Even a further 4 weeks after treatment the examined sample showed a drop of egg
excretion to 0 EpG in 98,8% of the samples, in other words there were no signs of
prevailing resistance appearances towards the applied substance.
The present studies are further proof that the number of dewormings-especially in
young animals can be distinctly reduced by means of selective anthelminthic
treatments.
Egg excretion and therewith pasture land contamination can be clearly reduced by
means of this procedure.]
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Fabritius, C. (2009). Sozialstruktur einer Herde Islandpferde bei Veränderung der Gruppenzusammenstellung. Ph.D. thesis, , Hannover.
Abstract: Die Domestikation des Pferdes begann wahrscheinlich etwa 5500 v. Chr. in
Südosteuropa. In Mitteleuropa traten circa 3000 v. Chr. die ersten Hauspferde auf.
Grundsätzlich wird davon ausgegangen, dass sich die Ansprüche des Pferdes
hinsichtlich der Lebensbedingungen, welche sich im Laufe der Evolution über
Millionen von Jahren entwickelt haben, in der Obhut des Menschen nicht wesentlich
geändert haben. Für Pferde typisch ist das Leben im Sozialverband, der Herde
(Zeitler-Feicht 2008). Diese wird auch in den Leitlinien der Sachverständigengruppe
tierschutzgerechte Pferdehaltung (10. November 1995) empfohlen, sofern es nicht
durch zu häufigen Wechsel im Bestand zu einem Übermaß an Stress und
agonistischen Aktionen kommt.
Ziel der Arbeit war es, anhand eines nach der Literatur erstellten Ethogramms des
Sozialverhaltens des Pferdes, herauszufinden, inwieweit Änderungen der
Gruppenstruktur die sozialen Beziehungen beeinflussten. Die Fragestellung bezog
sich auf eine Herde in Offenstallhaltung. Um die eventuellen Veränderungen der
sozialen Interaktionen zu untersuchen, wurde erst die vorhandene Gruppenstruktur
der Herde festgestellt. Danach wurde ein Individuum aus der Herde entfernt und ein
anderes dazugestellt. Anschließend wurde die Gesamtgruppe in zwei Untergruppen
geteilt und nach einem gewissen Zeitraum erneut zusammengeführt. Dabei wurden
jeweils die Interaktionen der Pferde anhand des Ethogramms beobachtet,
aufgezeichnet und protokolliert.
Untersuchungsgegenstand war eine Herde Islandpferde, die in einer
Ausgangsgruppe von 16 Tieren gehalten wurde.
Die Beschreibung einer sozialen Ordnung im Allgemeinen und einer Rangordnung im
Besonderen wird in vielen Studien ausschließlich auf der Basis der Beobachtung und
Bewertung offensiv aggressiver Verhaltenselemente durchgeführt. Aggressives
Verhalten muss hingegen im Gegensatz zu Verhaltensweisen, die die Anerkennung
des sozialen Status des anderen Pferdes bedeuten, wie Abwenden oder Meiden,
nicht notwendigerweise ein Anzeichen von Dominanz über ein anderes Tier
bedeuten (Van Hoof u. Wensing 1987, Schilder 1988). Ein weiterer Aspekt dieser
Arbeit sollte sein, eine Möglichkeit zu finden, die Sozialstruktur auch auf der
Grundlage defensiver und soziopositiver Verhaltenselemente zu definieren.
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Tang, A. C. (2003). A hippocampal theory of cerebral lateralization. In Hugdahl K. and Davidson R.J. (Ed.), The asymmetrical brain (pp. 37–68). Massechusetts: MIT Press.
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Aurich, J., Wulf, M., Ille, N., Erber, R., von Lewinski, M., Palme, R., et al. (2015). Effects of season, age, sex and housing on salivary cortisol concentrations in horses. Domest. Anim. Endocrinol., .
Abstract: Abstract Analysis of salivary cortisol is increasingly used to assess stress responses in horses. Since spontaneous or experimentally induced increases in cortisol concentrations are often relatively small for stress studies proper controls are needed. This requires an understanding of factors affecting salivary cortisol over longer times. In this study, we have analysed salivary cortisol concentration over 6 mo in horses (n = 94) differing in age, sex, reproductive state and housing. Salivary cortisol followed a diurnal rhythm with highest concentrations in the morning and a decrease throughout the day (P < 0.001). This rhythm was disrupted in individual groups on individual days; however, alterations remained within the range of diurnal changes. Comparison between months showed highest cortisol concentrations in December (P < 0.001). Cortisol concentrations increased in breeding stallions during the breeding season (P < 0.001). No differences in salivary cortisol concentrations between non-pregnant mares with and without a corpus luteum existed. In stallions, mean daily salivary cortisol and plasma testosterone concentration were weakly correlated (r = 0.251, P < 0.01). No differences in salivary cortisol between female and male young horses and no consistent differences between horses of different age existed. Group housing and individual stabling did not affect salivary cortisol. In conclusion, salivary cortisol concentrations in horses follow a diurnal rhythm and are increased in active breeding sires. Time of the day and reproductive state of the horses are thus important for experiments that include analysis of cortisol in saliva.
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Giles, S. L., Nicol, C. J., Harris, P. A., & Rands, S. A. (2015). Dominance rank is associated with body condition in outdoor-living domestic horses (Equus caballus). Applied Animal Behaviour Science, .
Abstract: Abstract The aim of our study was to explore the association between dominance rank and body condition in outdoor group-living domestic horses, Equus caballus. Social interactions were recorded using a video camera during a feeding test, applied to 203 horses in 42 herds. Dominance rank was assigned to 194 individuals. The outcome variable body condition score (BCS) was recorded using a 9-point scale. The variables age and height were recorded and considered as potential confounders or effect modifiers. Results were analysed using multivariable linear and logistic regression techniques, controlling for herd group as a random effect. More dominant (p = 0.001) individuals generally had a higher body condition score (p = 0.001) and this association was entirely independent of age and height. In addition, a greater proportion of dominant individuals fell into the obese category (BCS >= 7/9, p = 0.005). There were more displacement encounters and a greater level of interactivity in herds that had less variation in age and height, lending strength to the hypothesis that phenotypic variation may aid cohesion in group-living species. In addition there was a strong quadratic relationship between age and dominance rank (p < 0.001), where middle-aged individuals were most likely to be dominant. These results are the first to link behavioural predictors to body condition and obesity status in horses and should prompt the future consideration of behavioural and social factors when evaluating clinical disease risk in group-living animals.
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Wyss, C. (2015). Does housing in a „social box“ change faecal cortisol metabolites concentration in stallions? In Proceedings of the 3. International Equine Science Meeting.
Abstract: In order to improve the housing conditions of stallions in individual boxes by offering a possibility to have more social contact, the Swiss national stud farm tested a new box system for horses, allowing increased physical contact with the neighbouring stallion. The aim of this part of the study was to investigate whether this type of housing system (named “social box”) potentially induces a change in stress reactions in stallions compared to conventional boxes. Therefore faecal cortisol metabolite (FCM) concentration was measured as a non-invasive parameter to assess endocrine responses related to this new environment.
Four groups each consisting of eight adult Freiberger breeding stallions were included in the test design. Every stallion spent three weeks in a conventional box and in a social box respectively (cross-over design). The conventional box consisted of a separation wall with a lower opaque part and an upper part with vertical barriers (5 cm between barriers), allowing visual and olfactory contact but strongly limiting tactile contact. The separating wall of the social box consisted of two lateral sections, one part being opaque to the ceiling and the second part consisting of vertical barriers (30 cm between barriers), allowing the horse to have physical contact with its neighbour or to avoid it.
In horses, FCM concentration reflects an average level of circulating cortisol over a period of approximatively 24h. Faecal samples were collected the day following integration in social / conventional boxes, reflecting the potential stress induced by increased social interactions during the integration. In order to asses potential chronical stress, faeces samples were also collected in week one, two and three after the integration into the social / conventional box (in total: 4 samples per horse and housing system). The samples were immediately stored at -20°C until they were analysed. The samples were not analysed in the laboratory until the end of the experiment, therefore the duration of conservation in the freezer varied from 40 to 429 days.
A considerable percentage of data from groups 1 and 2 was below the detection limit (<0.8 ng/g) (Tab. 1). Thus the statistical analysis was conducted with the FCM concentration from groups 3 and 4 (n horses = 16) which contained no values below the detection limit.
Tab. 1: Details about FCM values and storage time for the 4 groups of stallions
Group Storage duration [d] Proportion of data below the detection limit (<0.8 ng/g) Mean [ng/g] Median [ng/g]
Group 1 384-429 55.6 % 2.2 0
Group 2 315-360 25.5 % 5.8 6.3
Group 3 41-79 0.0 % 8.7 8.0
Group 4 40-85 0.0 % 5.8 5.4
Despite the impressive social interactions observed between the stallions directly after being introduced into the social boxes, we did not find any differences in FCM concentration between the stallions being introduced into the conventional box and the social box on the day of integration (social box: n samples = 16, mean±SD: 6.9±4.7 ng/g; conventional box: n samples = 16, mean±SD: 9.0±11.2 ng/g; Wilcoxon signed rank test V = 70, p = 0.94).
Overall the samples taken during integration and in week one, two and three did not show evidence of changes in FCM concentration in either housing system over a longer period of time (social box: n samples = 64, mean±SD: 7.9±6.2 ng/g; conventional box: n samples = 64, mean±SD: 6.6±3.4 ng/g; Linear mixed model (LMM), p = 0.56).
Our results suggest that the possibility of having physical contact with a conspecific does not induce changes in FCM concentration in breeding stallions. The considerable percentage of values below the detection limit in groups 1 and 2 seemed to correlate with the increasing duration of storage before analysis. During the IESM Network Meeting 2015, we would like to discuss possible methodological issues and the possibilities to correctly integrate these low values in the statistical analysis.
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Fuchs, C., Kiefner, C., Erhard, M., & Wöhr, A. C. (2015). Narcolepsy – or REM-deficient? In Proceedings of the 3. International Equine Science Meeting.
Abstract: Narcolepsy is a neurological sleep disorder characterized by excessive daytime sleepiness, cataplexy (loss of muscle tone), sleep paralysis and hypnagogic hallucinations, also called the „tetrad of narcolepsy“. Although the pathogenesis is not completely understood, the disorder is well described in humans and it has been shown that a lack of the hormone hypocretin (orexin) synthesized in the hypothalamus is crucial. Narcolepsy with cataplectic attacks has also been reported in dogs, horses, cattle (STRAIN et al., 1984) and a lamb (WHITE und DE LAHUNTA, 2001).
In dogs up to 17 breeds have been shown to be affected sporadically, while familial forms occur in dobermans, labrador retrievers and dachshounds (TONOKURA et al., 2007). In horses there appear to be two syndroms (HINES, 2005), the first in which animals are affected within a few days after birth (possibly a familial form, reported in Suffolk, Shetland ponies, Fell ponies, Warmbloods, Miniature Horse foals (MAYHEW, 2011), Lipizzaner (LUDVIKOVA et al., 2012) and Icelandic horses (BATHEN‐NÖTHEN et al., 2009)) and the second in which animals are affected as adults (adult-onset narcolepsy).
It has been shown that both forms of canine narcolepsy are associated with a deficit in hypocretin/orexin neurotransmission (LIN et al., 1999). In the horse a similar etiology is suspected, but so far there are no studies to support this hypothesis.
The cataplectic attacks in humans and dogs occur during excitement or emotional stimulation such as laughing in humans or eating and playing in dogs. In contrast, the cataplectic or sleep attacks in adult horses happen almost exclusively while resting. The collapses observed in equines vary from drowsiness with hanging of the head, swaying, buckling at the knees or total collapse (see fig.1). Affected horses often show injuries and scars at the dorsal fetlocks, dorsal knees or at the face and the lips. ALEMAN et al. (2008) describe some of the suspected adult-onset narcolepsy cases as possible examples of sporadic idiopathic hypersomnia instead of true narcolepsy.
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König von Borstel, U., Kienapfel, K., McLean, A., Wilkins, C., Evans, D., & McGreevy, P. (2015). Hyperflexing the horse‘s neck: a cost-benefit and meta-analysis. In Proceedings of the 3. International Equine Science Meeting.
Abstract: In ethical discussions, a cost-benefit analysis requires that welfare costs associated with an activity can be reliably estimated and balanced against the potential benefits of the activity to both humans and animals. The current study applies a meta-analysis to the peer-reviewed evidence for costs and benefits of hyperflexion of the neck in horses; a practice that has attracted enormous public and scientific scrutiny over the past 15 years. A literature review identified 55 studies dealing with horses’ head and neck postures. Fourty-two of these studies examined the impact of various postures on equine welfare, for example, by assessing behavior, physiological stress parameters, health or rider-horse interaction. Thirty-five studies examined the impact of various postures on gymnastics (e.g. kinematics, shifts in weight distribution, muscle activity, airway functioning or overall workload). For the meta-analysis a dataset containing information from each of the individual studies was created. Data included information such as type, degree, duration and circumstances of hyperflexion applied in that particular study as well as information on the horses (e.g., sport discipline, level of training, breed) and on the study design (e.g., size of study and experimental or epidemiological research design). The results of the study regarding the impact of hyperflexion on a) welfare and b) gymnastics were coded as positive (1), insignificant or contradictory (0) or negative (-1). The significant majority of studies (88%) concluded that a hyperflexed head and neck posture negatively impacts welfare. Just one study suggested welfare advantages of training in a hyperflexed head and neck posture. An analysis using a generalized linear mixed model to assess the influence of the above factors collated in the dataset revealed that none of these factors significantly influenced the probability of a study to detect negative welfare implications. Thus hyperflexing the neck appears to impair horses’ welfare regardless of, for example, the duration or the way of achieving hyperflexion. A concurrent assessment of the evidence for gymnastic benefits showed that approximately one quarter of studies conclude that there may be benefits, while another quarter of the studies conclude that hyperflexion has detrimental effects on gymnastics. Thus, on the costs-side there is a clear reduction in equine welfare and some undesirable gymnastic effects, as well as likely a compromised profile of the equestrian sports in public. Benefits, on the other hand, include some desirable gymnastic effects, and potentially increased control of the horse for the rider. On balance, it appears that the costs associated with hyperflexion exceed the potential benefits of the activity to both humans and horses.
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Burla, J. B., Rufener, C., Bachmann, I., Gygax, L., Patt, A., & Hillmann, E. (2015). Effect of varying dimensions of the littered lying area on the lying behaviour of group-housed horses (Equus ferus caballus). In Proceedings of the 3. International Equine Science Meeting.
Abstract: Although horses can sleep while standing, recumbency is required for REM sleep and since all sleep stages must be completed for an entire sleep cycle, the opportunity for recumbency is essential for animal welfare. Observations on feral horses indicate a minimal lying duration of 30 min, preferably on a deformable and dry ground. In contrast to feral horses, lying behaviour in stabled horses is often affected by the dimensions of the provided lying area and rank.
In Switzerland, minimum requirements (MR) for the littered lying area are established by law to ensure animal welfare (BLV, 2008) (A/N: approximately match German recommendations (BMEL, 2009)). The aim of this study was to assess the adequacy of the dimensions of the minimum requirements for group-housed horses by investigating 38 horses in 8 groups. Further, hard rubber mats were provided supplementary in order to assess their suitability as an alternative to litter. Four treatments were each applied in randomised order:
– 0x MR: no litter + 1.5x MR with rubber mats
– 0.5x MR: 0.5x MR with litter + 1x MR with rubber mats
– 1x MR: 1x MR with litter; 0.5x MR with rubber mats
– 1.5x MR: 1.5x MR with litter + no rubber mats
For each treatment, after a habituation period of 8 days, lying behaviour was recorded (video, accelerometers) continuously for 72 hrs. Statistical analysis was performed using mixed effects models.
Regardless of the ground chosen, the duration of recumbency per 24 hrs was increasing with increasing dimensions of the littered area (F1,93 = 12.9, p = 0.0005; Fig. 1). Whereas the effect flattened from 1x to 1.5x MR, the duration spent on litter – a deformable ground – was increasing continuously (F1,62 = 23.1, p < 0.0001). Further, the proportion of lateral recumbency was increased with increased dimensions of the littered area (F1,79 = 12.3, p = 0.0007). Regarding the number of lying bouts, no differences were apparent between treatments providing litter, but recumbency occurred very seldom if only rubber mats were provided (F1,93 = 14.7, p = 0.0002). Further, low-ranking horses spent more lying bouts on rubber mats than high-ranking horses (F1,29 = 4.4, p = 0.04). Additionally, the larger the dimensions of the littered area the more horses were present in the lying area at the moment of lying down (F1,79 = 6.6, p = 0.01). Moreover, low-ranking horses showed considerably higher percentages of involuntarily terminated lying bouts than high-ranking horses if 0.5x and 1x MR were littered (F1,76 = 8.43, p = 0.005).
Although the indicated minimal lying duration was averagely performed, large individual differences occurred and at least 8% were lying down less than 30 min per 24 hrs in every treatment. Further, the inclusion of social parameters indicated a beneficial effect of an exceedance of the minimum requirements especially for low-ranking horses. Therefore, the minimum requirements established by Swiss law can be stated as adequate but should be perceived as minimum and not optimum dimensions.
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