Abstract: Horses are a highly social species living in complex social systems which should require them to memorise and generalise social experiences and distinguish between familiar and unfamiliar conspecifics. In the main part of my thesis I concentrated on the specific conflict situation of a horse being introduced into a new social group, and investigated its behaviour and stress level. Horses were either introduced (1) immediately, (2) after an observation period, or (3) together with an integration horse after an observation period. Additionally, in the second part of my thesis I arranged several experiments to elaborate additional aspects which could affect the behaviour of horses during introductions. In this study I could describe a simplified method for measuring stress through the analysis of faecal GCMs in horses. An enzyme immunoassay (EIA) for 11-oxoaetiocholanolone using 11-oxoaetiocholanolone-17-CMO: BSA (3?,11-oxo-A EIA) as antigen showed high amounts of immunoreactive substances. The new assay increases the accuracy of the test and lowers the expenses per sample; also storing of samples at room temperature after collection is less critical. This is a big advantage both in the field of wildlife management of equids and in the field of equestrian sports (chapter 1). Comparing the different introduction techniques, the introduction with an integration horse led to significantly less total interactions and lower levels of aggression than the introduction of single horses, both immediately and after several days of observing the new group. Additionally, by observing the behaviour of the horses during everyday sociality I could develop a formula describing the interrelationship between expected aggression level and enclosure size per horse. The curve takes an exponential shape. Starting from a space allowance of 300 m2 and more per horse, the amount of aggressions per hour approaches zero. For the reduction of aggression levels and injury risks in socially kept horses I recommend an enclosure size of at least 300 m2 per horse (chapter 2). I further investigated the stress level of the introduced animals. Horses which were immediately introduced did not show elevated faecal GCMs. In contrast, horses which were introduced after an observation period had slightly elevated values 2 and 3 days after the introduction. For horses introduced together with an integration horse faecal GCMs were significantly above the baseline value on the day of introduction and 1 day after it. These differences between introduction techniques indicate that the introduction event itself is not as stressful as previously assumed. Rather standing together with an integration horse and not being able to integrate immediately into the complete group elicits stress in horses (chapter 3). In the commentary of chapter 4 several studies are discussed which failed to demonstrate social learning in horses. It is argued that they did not consider important aspects which could have an influence, such as the dominance status or the social background of the horses (chapter 4). In chapter 5 a social feeding situation was investigated. The social rank as well as the position of conspecifics affected the feeding strategy of horses. Domestic horses used social cognition and strategic decision making in order to decide where to feed. When possible they tended to return to the same, continuously supplied feeding site and switched to an ?avoidance tendency? in the presence of dominant horses or when another horse was already feeding there (chapter 5). One possibility to recognize group members is through olfactory recognition. In chapter 6 it is shown that horses are able to distinguish their own from their conspecifics? faeces. In addition, they paid most attention to the faeces of those group members from which they received the highest amount of aggressive behaviour (chapter 6). Horses show cognitive abilities because they are able to use humans as local enhancement cues when searching for food, independently of their body posture or gaze consistency when the persons face them. Moreover, they seem to orientate on the attention of familiar persons more than of unfamiliar persons (chapter 7). Altogether, the results of this thesis provide further support for the view that horses show good conflict resolution strategies. They are perfectly able to deal with the conflict situation of being introduced to new group members, and the introduction event itself is not as stressful as previously assumed. It is rather suggested that standing together with an integration horse and not being able to integrate immediately into the complete group elicits stress in horses. All additional experimental set-ups could demonstrate that horses are well capable of social cognition.

Abstract: Ziel der Untersuchung war es, herauszufinden, welche Auswirkungen eine Erhöhung der
Gruppengröße bei Jungpferden auf die Bewegungsaktivität, das Liege- und Sozialverhalten
und die Körperkondition hat. Hierfür wurden insgesamt 42 Pferde im Alter von ein
bis zwei Jahren in Laufstallhaltung in die Untersuchung einbezogen. Die Jungpferde aus
der Bewegungs- und Liegeverhaltensanalyse waren in zwei Kleingruppen (acht und
11 Tiere) und einer Großgruppe (23 Tiere) aufgestallt.
In der Bewegungsaktivität waren deutliche Unterschiede zu erkennen. Es ließ sich ein
positiver Einfluss einer höheren Tierzahl nachweisen, aber kein Einfluss des Alters. Beim
Ruheverhalten konnten höhere Liegezeiten und -frequenzen mit einer Zunahme der
Gruppengröße und eine Abnahme der Liegezeit mit zunehmendem Alter ermittelt werden.
Eine Störung des Liegeverhaltens durch Gruppengrößen, die nicht der natürlichen
Herdenstruktur des Pferdes entsprechen, wurde nicht nachgewiesen. Jedoch hatte die
Haltung der Jährlinge in der großen Gruppe einen Anstieg der repulsiven Verhaltensweisen
zur Konsequenz. Zudem zeigte die Bestimmung des Body Condition Scores
Unterschiede in der Körperkondition bei den Jährlingen der Groß- bzw. der Kleingruppe.
Einem Mangel an Bewegung, der für das Auftreten von Gliedmaßenerkrankungen und
Verhaltensstörungen verantwortlich gemacht wird, kann durch die Haltung von Jungpferden
in großen Gruppen entgegengewirkt werden.
[It is often discussed that the inactivity of horses causes diseases of their musculoskeletal system. Due to these problems the objective of the investigation was to quantify if the size of a group has an effect on the behaviour of young horses. Data from 42 horses in the age of one to two years have been involved in the investigation. The data of two small groups were compared with data of one big group with 23 horses. The movement and lying behaviour of 28 horses were measured with ALT pedometers. The social behaviour of 33 yearlings was documented by direct observation. The results show that the median of the movement time of horses in group A is 82 minutes per day. In group B this increases to a median of 101 and group C reaches the highest median of 149. In the case of lying time an increasing group size leads to a longer duration and a higher frequency of lying, whereas an increase in the age reduces the lying duration. International research studies have shown that keeping of horses in big group husbandry systems is not very common by the owners of horses. In contrast these investigations have shown that horse keeping in big groups has no negative influence on the social behaviour and the Body Condition Score of young horses.]

Abstract: Frühere Untersuchungen haben gezeigt, dass die tägliche Bewegung für die Gesunderhaltung der Pferde notwendig ist. Inwieweit sich jedoch unterschiedliche Bewegungsangebote auf das Stress-und Bewegungsverhalten von Pferden in einer Gruppen-Auslaufhaltung auswirken und ob der Bewegungsbedarf der Pferde durch eine Auslaufhaltung ohne zusätzliche Bewegung gedeckt werden kann, ist der Literatur bisher nicht zu entnehmen. Daher sollte in der nachfolgend beschriebenen Untersuchung der Frage nachgegangen werden, welche Auswirkungen verschiedene Bewegungsangebote auf die Bewegungsaktivität von Pferden in Gruppen-Auslaufhaltungen haben und ob diese das Wohlbefinden der Tiere beeinflussen. Letzteres wurde durch Messung der Herzfrequenzvariabilität und Bestimmung von Cortisolmetaboliten im Pferdekot erfasst und die Bewegungsaktivität der Pferde wurde mit ALT-Pedometern bestimmt.
Verglichen wurden eine Einzel-und Gruppenhaltung mit jeweils angrenzendem Auslauf, aber ohne eine zusätzliche Bewegung der Pferde außerhalb des Stalls. In drei weiteren Varianten der Gruppenhaltung bekamen die Pferde täglichen Auslauf auf einer unbegrünten Koppel, auf einer Weide oder durch gezielte Bewegung in einer Führanlage. Die Bewegungsaktivität konnte durch die zusätzliche Bewegung in Form von Weide oder Führanlage signifikant gesteigert werden.
Ein zusätzliches Bewegungsangebot führte bei den Pferden zu einer Abnahme der Stressbelastung und sollte auch den Pferden ermöglicht werden, die in einer Gruppenhaltung gehalten werden, um ihre physische und psychische Gesundheit zu erhalten.
[Former studies confirm the necessity of daily movement for the health of a horse. But so far no description could be found in the literature how different movement offerings impact the stress and movement behaviour of horses in group husbandries with close-by discharge. The same holds true for the question whether a discharge husbandry system can meet the movement requirements of horses if there isn�t any additional movement possibility. The aim of the present study was to examine different movement offerings, their effects on the movement activities of horses in a group horse husbandry with close-by discharge and the impact of the movement on the wellbeing of the animals.
The heart rate variability and the concentration of the cortisol metabolites in the horse excrement were analyzed for detecting the wellbeing of the horses. Additionally ALT-Pedometers were used for determining the movement activity.
A single and a group husbandry system, each with closeby discharge, were compared when horses had no additional movement outside the stable. In three further variants the group husbandry was supplemented with daily time on a non-grassy pasture land, a pasture or in a horse walker. Pasture or horse walker increased movement activity significantly. Nevertheless an additional movement offering resulted in a lower stress load of the horses and should also be allowed to horses in group husbandry systems to ensure the horse�s physical and mental health.]

Abstract: Von der Basis bis zum Spitzensport werden Pferde gewaltsam zum “Gehorsam” gebracht oder zur Ausführung von Übungen gezwungen. Aktionen gegen die “Rollkur” oder “Hyperflexion” füllen die Medien. Aber die Wurzel des Übels liegt viel tiefer. Die Grundlage kultivierten Reitens in hoher Harmonie zwischen Mensch und Pferd ist eine feinfühlige, nahezu unsichtbare Hilfengebung, für die Bewegungen des Pferderückens und des Pferderumpfes den Zeitgeber liefern. Das Wissen darum in der Reiterwelt zu verankern, ist noch immer nicht gelungen.