Abstract: In recent years, the concept of self-organization has been used to understand collective behaviour of animals. The central tenet of self-organization is that simple repeated interactions between individuals can produce complex adaptive patterns at the level of the group. Inspiration comes from patterns seen in physical systems, such as spiralling chemical waves, which arise without complexity at the level of the individual units of which the system is composed. The suggestion is that biological structures such as termite mounds, ant trail networks and even human crowds can be explained in terms of repeated interactions between the animals and their environment, without invoking individual complexity. Here, I review cases in which the self-organization approach has been successful in explaining collective behaviour of animal groups and societies. Ant pheromone trail networks, aggregation of cockroaches, the applause of opera audiences and the migration of fish schools have all been accurately described in terms of individuals following simple sets of rules. Unlike the simple units composing physical systems, however, animals are themselves complex entities, and other examples of collective behaviour, such as honey bee foraging with its myriad of dance signals and behavioural cues, cannot be fully understood in terms of simple individuals alone. I argue that the key to understanding collective behaviour lies in identifying the principles of the behavioural algorithms followed by individual animals and of how information flows between the animals. These principles, such as positive feedback, response thresholds and individual integrity, are repeatedly observed in very different animal societies. The future of collective behaviour research lies in classifying these principles, establishing the properties they produce at a group level and asking why they have evolved in so many different and distinct natural systems. Ultimately, this research could inform not only our understanding of animal societies, but also the principles by which we organize our own society.

Abstract: Group turnout provides important socializing opportunities for horses, particularly those that are primarily stalled. A high percentage of equine injuries occur during group turnout, which could partly be due to the physical constraints of fencing. To investigate appropriate paddock sizes for group turnouts, horses (n = 12) from a single herd were divided into groups of 4, stalled for 24 hours, and then turned out for 1 hour into one of three differently sized pens: 342, 263, and 184 m2 per horse. Groups rotated through pens across 3 days, receiving one treatment per day. Blood was sampled for cortisol concentrations at 08:00 hours each morning, and then at 15 and 60 minutes into the turn out sessions, and 60 minutes after return to individual stalls. Groups rotated through three turnout times: 09:00, 12:00, 14:00 hours. Counts of agonistic behaviors (chasing, contact biting, and kicking) and low-level threats (pinned ears, tail swishing, bite and kick threats) were recorded. When turned out in pens that provided 342 m2 per horse, horses exhibited reduced plasma cortisol concentrations by 15 minutes after turnout and at 1 hour after return to their stalls (P < .05). Horses in pens providing 184 m2 per horse exhibited greater agonistic (P < .001) and low-level threat (P < .01) behaviors than horses in larger pens. These data provide insight into appropriate pen sizes for horses from established herds. Providing at least 342 m2 per horse may reduce the chance of injury in horses accustomed to group turnout.

Abstract: Das EU-Projekt AWIN (Animal Welfare Indicators) hat zum Ziel, ein weltweites Netzwerk zum Thema Tierschutz und Wohlbefinden von Tieren zu erstellen, durch welches Forschungsergebnisse und neue Erkenntnisse ausgetauscht werden können. Diese Informationen sollen auch dem Gesetzgeber zur Verfügung gestellt werden, um neue Gesetze auf wissenschaftlichen Grundlagen beschließen zu können. Des Weiteren soll diese Plattform zu Trainingszwecken genutzt werden, damit Personen, die im Bereich Tierschutz arbeiten, sich fortbilden können.
In vier Arbeitsgruppen wird am Tier zum Thema Wohlbefinden und Schmerz geforscht. In der ersten Arbeitsgruppe werden Beurteilungsprotokolle für Ziegen, Schafe, Pferde, Esel und Puten erarbeitet, um Wohlbefinden und Schmerz objektiv bestimmen zu können. Dabei geht es sowohl um die Erfassung individueller Parameter, als auch um haltungsbedingte Parameter wie Tierdichte, Gruppengröße oder Mensch-Tier-Interaktion. Das Ziel dieser Protokolle ist die einfache Anwendbarkeit auf große Tierbestände.
Die zweite Arbeitsgruppe erforscht die Beziehung zwischen Wohlbefinden und Krankheit bzw. Schmerz. Der Einfluss von akuten oder chronischen Schmerzen kann das Wohlbefinden erheblich beeinträchtigen. Anhand des Krankheitsbildes der akuten und chronischen Hufrehe sowie durch den chirurgischen Eingriff einer Kastration an gesunden Pferden sollen Schmerzindikatoren am Pferd erforscht werden. Die akute Hufrehe dient als Modell für sehr starke Schmerzen. Die Schmerz-assoziierten physiologischen Parameter Herzfrequenzvariabilität und Zytokinreaktion im Blut werden bestimmt. Mit einem Schmerzbeurteilungsbogen werden außerdem ethologische Parameter wie z. B. Körperhaltung, Kopfbewegungen, Lahmheitsgrad, abnormale Gewichtsverlagerungen, Mensch-Pferd-Interaktionsverhalten und weitere physiologischen Parameter wie Atemfrequenz, Herzfrequenz, Darmgeräusch und Körpertemperatur erhoben. Durch das Krankheitsbild der chronischen Hufrehe sollen die ermittelten Schmerz-assoziierten Parameter auf ihre Aussagefähigkeit auch für weniger starke Schmerzen überprüft werden. In der Kastrationsstudie werden Basiswerte ohne Schmerzen vor dem chirurgischen Eingriff erhoben und mit den Werten nach der Kastration verglichen. Neben den oben genannten Parametern werden zusätzlich Cortisolmetaboliten im Kot bestimmt und es werden Videoaufzeichnungen von der Mimik des Pferdes gemacht und ausgewertet. Außerdem soll der Einsatz von Schmerzmitteln vor und nach der Kastration und deren Einfluss auf das Befinden des Pferdes nach der Operation erforscht werden. Das Forschungsziel der zweiten Arbeitsgruppe ist die Bestimmung von geeigneten Messparametern, durch die Schmerz objektiv beurteilt werden kann.
Die dritte Arbeitsgruppe beschäftigt sich mit dem Einfluss von pränatal erlebtem Stress auf die Individualentwicklung des Fohlens. Veränderungen in der Herdenstruktur, soziale Isolation oder abruptes Absetzen des letzten Fohlens während sensibler Trächtigkeitsphasen beeinflussen die tragende Stute und den Foetus. Nach der Geburt wird das Verhalten der Mutterstute und die Entwicklung des neugeborenen Fohlens beobachtet.
In der vierten Arbeitsgruppe schließlich wird das wissenschaftliche Netzwerk zusammengesetzt. Neben wissenschaftlichen Forschungsergebnissen und Publikationen werden auch Lernmaterialien („learning objects“) erarbeitet und zur Verfügung gestellt. „Learning objects“ sind digitale Lernmaterialien, in denen spielerisch Stück für Stück der Lerninhalt interaktiv erarbeitet werden kann.

Abstract: The aim of this study was to evaluate the behavior and physiologic responses of mares to removal from an established pasture herd and to isolation in a pasture setting for 6 h (Group I, n=5). Responses of mares in Group I were compared to mares that were transported and returned to the herd (Group T, n=5) and to mares moved to the isolation pasture with a companion (Group C, n=5). Behavior was recorded continuously for 6 h on the day before the isolation procedures (baseline, Day 0) and again on the day of the procedure (test, Day 1). Plasma cortisol, white blood cell count (WBC), neutrophil:lymphocyte ratio (N:L), and hematocrit (HCT) were measured once on Day 0 (a.m.) and twice on Day 1 (a.m. and p.m.). Heart rate (HR) was monitored continuously during Day 0 and Day 1. Intradermal response to phytohemagglutinin (PHA) injection was measured 18 h following injection, which was administered at the end of Day 1. Average time spent standing alert increased (P<0.05) in Groups I and C and average time spent grazing decreased (P<0.05) in Group C from Day 0 to Day 1. Also, there was a significant difference between groups (based on a calculated χ2-square value) in the proportion of mares that autogroomed, defecated, urinated, rolled, and whinnied on Day 1. Activity shift rate (ASR) and temperament scores increased significantly in Groups I and C from Day 0 to Day 1 (P<0.05). Plasma cortisol increased significantly in all groups from Day 0 to Day 1, a.m. (P<0.05) and decreased significantly from Day 1, a.m. to Day 1, p.m. (P<0.05). HCT significantly increased in all three groups from Day 0 to Day 1, a.m. (P<0.05). WBC significantly increased in Group T from Day 0 to Day 1, a.m. (P<0.05). N:L ratio significantly increased in Groups I and C from Day 0 and Day 1, a.m. to Day 1, p.m. (P<0.05). A variety of measures did indicate a response to removal from the pasture group, however, the overall, short-term response was minimal. Since the responses of Groups I and C were similar, the effects of isolation versus a novel environment or separation from the established herd could not be differentiated.

Abstract: Assessing the animal welfare state is a challenge given the subjective individual cognitive and emotional processing involved. Electroencephalography (EEG) spectrum analysis has proved an ecologically valid recording situation to assess the link between brain processes and affective or cognitive states in humans: a higher slow wave/fast wave ratio has been associated with a positive internal state. In particular, a high production of theta power (3-8 Hz) has been related to positive emotions. On the other hand, it has been hypothesized that a left hemisphere (LH) dominance may be associated with a better welfare state. Here, we test the hypothesis that individual differences in the resting-state quantitative EEG power spectrum of adult horses (N = 18) and its lateralization pattern may reflect individual subjective perception of their conditions of life and welfare state. The results show clear individual differences in the proportions of the different waves and their inter-hemispheric distribution. Three different EEG power spectrum profiles were highlighted, from a bilateral predominance of theta waves in horses in a more positive welfare state to a bilateral predominance of beta waves in horses with clear expressions of compromised welfare. Interestingly, particular correlations were found between wave power activity and welfare parameters. We found a negative correlation between the number of stereotypic behaviours per hour and the median proportion of theta waves in the left hemisphere. and between the overall state (total chronic stress score) of welfare and gamma production in the right hemisphere (RH). These findings go along the hypothesis of a particular involvement of the left hemisphere for positive processing and of the right hemisphere for negative processing. However, the pattern of laterality did not appear as the most important feature here as both extreme clusters in terms of welfare showed bilateral predominance of one wave type. It is possible that hemispheric specialization makes more sense during acute emotion-inducing conditions rather than in this resting-state context (i.e. in absence of any high emotion-inducing stimulation), although the opposition gamma versus theta waves between both hemispheres in the horses with an intermediate welfare state is noticeable and intriguing. It seems that bilateral but also LH theta activity is a promising neurophysiological marker of good welfare in horses, while a bilateral or RH high production of gamma waves should alert about potential welfare alterations. Quantitative resting-state EEG power spectrum appears as a highly promising tool for exploring the brain processes involved in the subjective perception of chronic welfare, as a useful complementary tool for welfare assessment.