Abstract: Durch die vorliegende Studie wurde der Einfluss von Strukturelementen auf das Liege- und Aggressionsverhalten von Pferden in Gruppenhaltung untersucht. Die Strukturelemente sollten Rückzugsmöglichkeiten bieten, sowie in ihrem Bereich zur Aufhebung der Individualdistanz führen und dadurch die Fläche relativ vergrößern. Für die Versuche stellte das Haupt- und Landesgestüt Marbach drei unabhängige Pferdegruppen mit verschiedener Herdengröße zur Verfügung, die jeweils in Einraum- Innenlaufställen gehalten wurden. Die Datenerfassung fand zwischen 23 und sieben Uhr statt. Insgesamt wurden 366 Stunden Videomaterial ausgewertet. Beim Ruheverhalten wurden mit Hilfe des event-sampling- Verfahrens die Parameter Gesamtliegedauer, Dauer in Seitenlage, Dauer der Einzelphasen in
Seitenlage und Abliegehäufigkeit pro Nacht erfasst. Es wurden Versuchsphasen ohne
Strukturelemente und mit hängenden Planen als Strukturierung durchgeführt. Im ersten Stall
kamen außerdem über einander gestapelte Strohballen zum Einsatz. Diese Art der
Strukturierung stellte sich jedoch als nicht praktikabel heraus und führte im Vergleich zu den Planen zu einer signifikanten Verschlechterung der Gesamtliegedauer. In Stall 1 konnte man eine tendenzielle Verbesserung der Parameter Gesamtliegedauer und Gesamtdauer in Seitenlage durch das Anbringen von Planen sehen. In Stall 3 dagegen verschlechterte sich das Ruheverhalten in den Versuchsphasen mit Planen gegenüber den Versuchsphasen ohne Struktur. Die Werte der Gesamtdauer in Seitenlage nahmen signifikant ab. In Stall 2 zeigten sich keine Unterschiede in den verschiedenen Versuchsphasen. Möglicherweise ist die Wirkung der Strukturelemente auf das Liegeverhalten abhängig von der Flächengröße. Stall 1 hatte bezogen auf die Leitlinien des BMELV die größte und Stall 3 die kleinste Fläche. Bei den anderen Parametern des Liegeverhaltens gab es keine signifikanten Unterschiede in den verschiedenen Versuchsphasen. Mit Hilfe des time-sampling-Verfahrens wurde die Anzahl gleichzeitig liegender Pferde und gleichzeitig liegender Pferde in Seitenlage bestimmt. Auch hier zeigten sich keine Unterschiede in den verschiedenen Versuchsphasen. Bei der Gegenüberstellung der Werte der Gesamtliegedauer und der Gesamtdauer in Seitenlage mit dem Alter der Pferde (Stall 1 und Stall 3) und mit dem Integrationszeitpunkt (Stall 1) konnte kein Zusammenhang festgestellt werden. Beim Aggressionsverhalten wurden mit Hilfe des
event-sampling-Verfahrens in den Ställen 2 und 3 verschiedene Arten von Aggressionen
erfasst, die dann in die drei Intensitätsgrade Low-Level-, Mid-Level- und High-Level-
Aggressionen unterteilt wurden. Neben der Anzahl wurde die Dauer der verschiedenen
Aggressionen bewertet. Insgesamt konnte eine positive Wirkung der Planen auf das
Aggressionsverhalten beobachtet werden. Die Gesamtanzahl an Aggressionen nahm in beiden
Ställen tendenziell in den Versuchsphasen mit Planen ab. In Stall 3 konnte, wenn man die
Aggressionen stundenweise betrachtet, ein signifikanter Unterschied festgestellt werden.
Auch der Hinterhandschlag und die Aggressionen, welche das Ruheverhalten stören,
verringerten sich tendenziell nach dem Anbringen von Strukturelementen. In beiden Ställen
nahm die relative Häufigkeit von Mid-Level-Aggressionen nach dem Anbringen von Planen
zu. Dagegen konnte bei den High-Level-Aggressionen und in Stall 3 bei den Low-Level-
Aggressionen eine relative Abnahme beobachtet werden. Sowohl die Anzahl als auch die
Dauer der Mid-Level-Aggressionen verringerten sich in Stall 3 stundenweise betrachtet
signifikant in den Versuchsphasen mit Planen. In Stall 2 war bei den High-Level-
Aggressionen sowohl bei der Dauer als auch bei der Anzahl eine signifikante Abnahme zu
sehen. Wenn man das Aggressionsverhalten in Bezug zu der Fläche in den zwei Ställen
betrachtet, schien diese vor allem einen Einfluss auf die High-Level-Aggressionen zu
nehmen. Mit Hilfe des Rangindex der Pferde im Stall 3 wurde eine Rangordnung aufgestellt.
Zwischen dem Platz der Pferde in der Rangordnung und den Parametern des Ruheverhaltens
(Gesamtliegedauer, Gesamtdauer in Seitenlage) sowie dem Alter der Pferde konnte kein
Zusammenhang festgestellt werden. Zwischen dem Rangindex und der Gesamtanzahl an
Aggressionen bestand dagegen ein hoch signifikanter Zusammenhang. Im Rahmen dieser
Studie ist das Anbringen von Strukturelementen in Bezug auf das Aggressionsverhalten in
Einraum-Innenlaufställen von Pferden zu empfehlen. Die Wirkung auf das Liegeverhalten der
Pferde sollte in weiteren Studien untersucht werden.
[In this study the influence of structural elements on lying and aggression behavior in horses
kept in groups was exanimated. Structural elements should offer the possibility of retreat.
Furthermore, within the respective area, the individual distance should be limited, thus
increasing the overall space relatively. For the studies the “Haupt- und Landesgestüt
Marbach” provided three non-related groups of different sized horses, each kept in separate
“Einraum-Innenlaufställen”. Data collection took place between 11 pm and 7 am. Altogether,
366 hours of video material were analyzed. Using the event-sampling-method, the following
parameters within the horses´ resting behavior were determined: The total lying period, the
total lying period in lateral position, the periods of the single lying in lateral position and the
frequency of lying down. Test phases were carried out without structural elements and with
hanging canvases as structural elements. In the first stable there were also three bales of straw
piled up on top of each other. This kind of structuring emerged as impractical and in
comparison to the canvas, led to a significant deterioration to the total period of lying. After
the canvases were fixed in the first stable, a slight improvement with the parameters of total
lying period and total lying period in the lateral position could be seen. In contrast, the resting
behavior in stable 3 worsened in the test phases with the canvases in comparison to the test phases without structural elements. The values for the total lying period in the lateral position
decreased significantly. In stable 2, there were no differences in the different test phases.
Possibly the effect of the structural elements is dependent of the space. Stable 1 had the
largest space and stable 3 the least space referred to the guideline of the BMELV. The other
parameters of the lying behavior showed no significant differences in the different test phases.
The number of horses lying at the same time, and the number of horses lying at the same time
in the lateral position were detected with the aid of the time-sampling-method. There were
also no differences between the different test phases. If the values of the total lying period and
the total lying period in lateral position were compared to the age of the horses (stable 1 and
stable 3) and to the point of integration (stable 1), there was no correlation.
Different kinds of aggression were detected by the means of the event-sampling-method in
stable 2 and 3 and were subdivided into the three levels of intensity: Low-level-, mid-level
and high-level-aggressions. Both the number and the duration of the different aggressions
were evaluated. All in all a positive influence of the canvas on the aggression behavior could
be observed. In both stables, the total number of aggressions decreased in the test phases with
canvases. In stable 3 a significant difference could be detected, if the aggressions were
observed per hour. Also hind limb kicks and aggressions disturbing the resting behavior,
decreased by trend, after fixing the canvases in the stable. In both stables the relative
frequency of mid-level-aggressions increased after the canvases were mounted. In contrast
there was a relative decrease at the high-level-aggressions and in stable 3 at the low-levelaggressions.
The number and the duration of the mid-level-aggressions in stable 3 decreased,
when considered by the hour in the test phases with canvases. In stable 2 a significant
decrease in duration and number of high-level-aggressions was observed. When examining
aggression behavior in reference to space in the two stables, high-level-aggressions seemed to
be mostly influenced. In stable 3 a rank order was established with the aid of the rank index of
the horses. There was no correlation between the horses´ rank and the parameters of the
resting behavior (the total lying period, the total lying period in lateral position) and between
horses´ rank and age. In contrast, there was a high significant correlation between the rank
index and the total number of aggressions. In context to this study, structural elements in
“Einraum-Innenlaufställen” (BMELV 2009) seem to have a positive influence on the
aggression behavior and thus seem to be recommendable. The influence on the lying behavior
should be investigated in further studies.]

Abstract: Earlier research indicates that stallions might either prevent social interactions between mares in their
herds directly or indirectly by their presence (Feist and McCullough, 1976; Sigurjonsdottir et al.,
2003) The impact of stallions on the social interactions between harem members was studied in 6
groups of Icelandic horses in 2004, 2006 and 2007 for altogether 525 hours. Four of the groups were
permanently living together under semi-feral conditions, while two were temporary breeding groups. In
addition, temporary and permanent groups were compared and the effect of the stability of the group
on the social behaviour of horses was investigated .
The results show that stallions seldom intervene directly in social interactions between harem
members. However, the hierarchies were less rigid and fewer friendship bonds were found in the
groups compared to what has been found in groups without stallions in Iceland. These results give
some support to our prediction that the stallion does indirectly suppress social interactions of herd
members.
The stability of the group was found to affect the aggression rate, since a higher aggression rate was
found in the temporary groups compared to the permanent groups. The number of preferred
allogrooming partners of the horses was also affected to some extent, as a significantly lower number
of allogrooming partners was found in the most unstable group compared to all the other groups. The
results have significance for further research in the field of social structure of mammals, and may also
be applied in the management of horses and other domestic animals.

Abstract: Elevated urinary catecholamines and their metabolites are the only findings which confirm the presence of pheochromocytoma. This examination is of particular interest if carried out in urine produced after spontaneous hypertensive episodes. Pharmacologic tests when carried out under standard conditions have proven to be a reliable aid in cases of suspected pheochromocytoma. Roentgenographic studies, determination of local plasma catecholamine concentrations and blood volume control should be undertaken in these patients before surgical procedure.

Abstract: Evidence suggests that behavioural affective reactions to sweet and bitter substances are homologous in humans, nonhuman primates, and rodents. The sweet taste of sucrose elicits facial responses that include rhythmic tongue protrusions whereas the bitter taste of quinine elicits facial responses that include gapes, featuring an opening of the mouth and protrusion of the tongue. The present study using the horse (Equus caballus) was undertaken for three reasons: (1) there is debate about the presence of a sweet receptor gene in the horse, (2) there is a need to expand the examination of facial reactions to taste in lineages other than the closely related lineages of rodents and primates, and (3) the horse provides an opportunity to test the hypothesis that some social signals derive from movements related to taste reaction. The horses were given oral infusions of either sucrose or quinine and their behaviour was examined using frame-by-frame video analysis. Control groups were exposed received water or syringe insertion only. Amongst the many responses made to the infusions, the distinctive response to sucrose was a bob coupled with a slight tongue protrusion and forward movement of the ears; the distinctive response to quinine was a head extension and mouth gape accompanied by a large tongue protrusion and backward movement of the ears. Sucrose Bobs and Quinine Gapes are discussed with respect to: (1) the relevance of facial reactions to both sucrose and quinine to taste receptors in horses, (2) the similarity of features of taste expression in horses to those documented in rodents and primates, and (3) the dissimilarity between facial reactions to taste and other social signals displayed by horses.

Abstract: Feral horses are social animals, which have to rely on survival strategies centered on the formation of cohesive social bonds within their bands. Many problems in the husbandry of social animals such as horses, are due to the fact that the limits of their adaptive abilities are exceeded. Evidence suggests that the fundamental social characteristics of domestic horses have remained relatively unchanged. The social structure, social strategies and social interactions were investigated (3 non-consecutive years, 24 hr per day for several weeks) in long term established groups of domestic horses (mares and geldings of all ages) and a few small introduced groups, kept in (semi)natural environments. The general aim was to investigate the social needs of domestic horses. The social life of domestic horses was characterised by long lasting bonds with preferred partners which were established and maintained by allogrooming, play, proximity and dominance behaviours. Bonding partners were mainly found within the same sex-age group, but adult geldings also bonded with sub-adult mares and geldings. Adult mares were clustered in a group, while the other animals formed a second group. Among the adult mares, subgroups according to reproductive state were formed. Individuals regulated their social network by interfering with interactions between other members of the herd, which in itself is complex. An intervention is a behavioural action of one animal that actively interferes with an ongoing interaction between a dyad with the apparent aim of altering that interaction. This was verified by post-hoc analyses of disturbed and undisturbed interactions. Interventions in allogrooming or play were performed significantly more often when at least one member of the initial dyad was a preferred partner of, or familiar to (within the small introduced bands) the intervener. The stronger the preferred association in allogrooming between the intervener and member(s) of the initial dyad, the higher the probability the intervener would displace one initial member and continue allogrooming with the other. Just five behaviours were extracted which reliably reflected the dominance relations among horses. Aggression with the hind quarters was used both offensively and defensively and therefore not suitable as a reliable parameter. Individual dominance relationships were related to social experience. The implications of these findings for horse husbandry were assessed. It is argued that the execution of affiliative behaviours may be rewarding in itself, and therefore always will be a highly motivated behaviour. It is shown that social positive physical interactions (allogrooming, play) with other horses is an ethological need and therefore indispensable in modern husbandry systems. Ethological needs are so important for the animal that husbandry systems that lack the possibilities to execute such behaviours will cause chronic stress. It is concluded that all horses need physical social contact, and that horses, which lack appropriate social learning experiences during ontogeny, may be hampered in their social functioning later in life. Solutions for problems, including dominance problems, in individual social housing and group housing are presented.