Abstract: Horses provide an interesting animal model to test short- and long-term effects of the paternal influence on the offspring under natural conditions. As a highly social animal, horse naturally is living in long-term harem groups building strong familiar bonds. Arguing that the environment of a juvenile is highly important for the development of cognitive and social functions as well as for the emotional competence, a future study on domestic horses wants to highlight the paternal influence on the offspring as well as special effects of the stallion during the first two years of the foals´ life. Nowadays, in most husbandry systems it is still common to keep the stallions separated, raising the offspring in an intact harem group is very rare. The aim of this study is to describe the role of the stallion in the early development of the foal in an extensive pasture management system living in natural harem groups. Results are going to be compared to findings of studies on groups without the male present in the rearing phase. A precise behavioural analysis is planned; direct behavioural observations are going to be supported by long-term and continuously activity measures by special telemetry collar systems. Additional physiological measures should give evidence of the investment of the stallion. The young horses will be confronted with different tests of cognitive and social abilities (exploration behaviour, fear behaviour, play behaviour). The results of this study will contribute to fundamental research in the behaviour of the horse and might display an important step to animal welfare in modern horse husbandry. It will be possible to set a time-frame in which the male does have positive influence on the offspring and therefore should be kept with the family. A detailed knowledge of the influence of the male to cognitive and social abilities could as well be applicable in the training of horses and therefore be of great importance in equestrian sports.

Abstract: In dieser Untersuchung sollte überprüft werden, ob die für die Stressmessung beim Menschen angewandte „Chronopsychobiologische Regulationsdiagnostik“ (CRD) mithilfe des smardwatch®-Messsystems auch beim Pferd psychische Belastungssituationen aussagekräftig widerspiegelt. Menschen können anhand variierender physiologischer und ethologischer Reaktionen auf Stressoren aus der Umwelt in Stresstypen eingeteilt werden. Auch Pferde reagieren in identischen Situationen ganz unterschiedlich. Es stellte sich daher die Frage, ob Pferde ebenfalls bestimmten Stresstypen zugeordnet werden können.
Mit 26 dreijährigen Hengsten des Landgestüts Celle wurde ein Verhaltenstest durchgeführt. Auf der Grundlage wissenschaftlich dokumentierter und modifizierter Testsituationen (Open-Field-Test, Novel-Object-Test, Startling-Test Objekt/Geräusch, Mensch-Pferd-Interaktion, Ressourcenkontrolle) wurde das Erkundungs- und Fluchtverhalten untersucht (Goslar 2011). Während dieser Belastungssituationen wurden mit dem smardwatch®-Messgerät die elektrophysiologischen Parameter Hautwiderstand, Hautpotential und Muskelaktivität erfasst. Durch eine Zeitreihenmessung dieser physiologischen Parameter konnten die Reaktionen des übergeordneten Reglers (vegetatives Nervensystem) dargestellt werden. Der Hautwiderstand spiegelt die vegetativ-emotionalen Reaktionen wider, das Hautpotential die vegetativ-nervalen und somit laut Balzer (2009) die kognitiven Verarbeitungsweisen, und durch das Elektromyogramm werden die typischen muskulär-motorischen Reaktionen aufgezeichnet. Die vorliegenden Datenzeitreihen wurden mit Hilfe einer biorhythmometrischen Zeitreihenanalyse nach Balzer und Hecht (Hecht 2001, Balzer 2009) ausgewertet. Als Ergebnis wurden chronobiologische Regulationszustände definiert, die dann gemäß dem „Periodischen System der Regulationszustände“ (PSR) (Balzer 2000) eine Beurteilung der psychischen Belastungssituation erlauben. Zur Bestimmung von Stresstypen wurde die Untersuchung nach dem Reiz-Reaktions-Prinzip in drei Phasen unterteilt: Ruhephase, Stressreizphase und Stressverarbeitungsphase. Der Verhaltenstest wurde nach einer Woche zur gleichen Tageszeit mit jedem Hengst einmal wiederholt. Als physiologische Vergleichsparameter wurden vor, während und nach der Belastung insgesamt zehn Speichelproben zur Cortisolbestimmung entnommen.
Die smardwatch®-Messtechnik ist prinzipiell geeignet die physiologischen Parameter Hautwiderstand, Hautpotential und Muskelaktivität auf der Haut des Pferdes aufzunehmen. Durch die biorhythmometrische Zeitreihenanalyse konnten chronobiologische Regulationszustände definiert werden.
Der Verhaltenstest führte bei allen Pferden zu einem signifikanten Anstieg der Cortisolwerte. Ein ebenfalls statistisch gesicherter Unterschied der aktivierten Cortisolwerte zwischen der ersten und zweiten Testwoche zeigt eine geringere Stressreaktion und weist auf einen Lerneffekt der Pferde hin:
Entsprechend der relativen Instabilitäten der Regulation der Körperfunktionen in Messphase 2 und 3 konnten die Pferde in vier Stressregulationstypen (nach Balzer u. Hecht 1996) eingeteilt werden: Stressbeherrscher, -bewältiger und kompensierer sowie Stressnichtbewältiger.
Anhand der Aktivierung von Sympathikus und Parasympathikus konnten zusätzlich vier verschiedene Vegetative Stresstypen unterschieden werden: Sympathikotoniker, Amphotoniker, Indifferenter Typ und Vagotoniker.
Die Cortisolreaktion der Hengste war individuell sehr unterschiedlich. Um die maximalen Anstiege vergleichen zu können, wurde der Trend der jeweiligen Cortisolverlaufskurve bestimmt. Anhand der Trend-korrigierten Cortisolkurven konnten einerseits die relativen Maxima der Cortisolreaktion besser verglichen werden, anderseits konnten die Pferde mittels des unterschiedlichen Trendes in drei Cortisolverlaufsgruppen eingeteilt werden: Tendenz fallend, gleichbleibend oder steigend.
Ein statistischer Nachweis für eine Abhängigkeit zwischen den verschiedenen Stresstypenklassifizierungen konnte anhand der geringen Stichprobenzahl nicht erbracht werden. Jedoch lassen sich Pferde, wie Menschen, unterschiedlichen Stresstypen zuordnen. Schwierig bleibt aber die objektive Beurteilung von Befindlichkeiten, da Empfindungen und Gefühle nur subjektiv wahrnehmbare Qualitäten sind, die von einer Reihe innerer und äußerer Faktoren abhängen. Die Verhaltenszuordnung emotionaler Zustände durch die „Chronopsychobiologische Regulationsdiagnostik“ (CRD) kann nicht ohne die Basis weiterer vergleichender Studien vom Mensch auf das Pferd übertragen werden.
Die CRD-Methode könnte allerdings einen interdisziplinären Ansatz ermöglichen und zukünftig neben den klassischen deskriptiven Verhaltensbeobachtungen bei der Beurteilung von Haltungs- und Umgangssituationen von Tieren wertvolle Aufschlüsse über die Fähigkeit zur Stressbewältigung und deren Konsequenzen für das Wohlbefinden der Tiere geben.
In this study we examined, whether the “Chronopsychobiological regulation diagnosis” (CRD) with the smardwatch®-system which is used to assess specific strain in humans, is also able to reflect convincingly specific strain in horses. Humans can be categorized into so-called stress types, because they react differently in physiology and behaviour to environmental stimuli. Concerning horses, it is also known that individuals react differently in identical situations. The question to be answered is, if it is possible to categorize horses into certain stress types as well.
We carried out a behavioural test with 26 three-year-old stallions of the State Stud of Celle, involving different test situations. On the basis of test situations, well known in scientific literature including slight modifications (open-field-test, novel-object-test, startling-test object/sound, human-horse-interaction, resource control) the explorative and flight behaviour of horses were examined (Goslar 2011). During these situations of strain the system smardwatch® measured the electro-physiological parameters skin resistance, skin potential and muscle activity. With time series analyses of these physiological parameters the reactions of the vegetative nervous system as superior control could be shown. The skin resistance reflects the vegetative-emotional, the skin potential the vegetative-nervous hence according to Balzer (2009) cognitive reactions and the electromyogram shows the motorized reactions. The time series of measured data was analyzed using the biorhythmometrical time series analysis of Balzer and Hecht (Hecht 2001, Balzer 2009). As a result of this, typical states of chronobiological regulation were defined. With the help of the “periodic system of regulatory states” (PSR) (Balzer 2000) these led to a classification of mental stress situations. To categorize horses into stress types the study was devided into three phases according to the stimulus-response principle: phase 1 (relaxing), phase 2 (situation of strain) and phase 3 (stimulus processing phase). The behavioural test was repeated once with each stallion exactly one week later. In addition ten samples of saliva were taken before, during and after the situations of strain from which we determined the cortisol concentration to be compared with the chronopsychobiological parameters.
The smardwatch®-measurement technology is fundamentally suitable to measure the physiological parameters skin resistance, skin potential and electrical muscle activity of horses. Using the biorhythmometrical time series analysis, chronobiological regulatory states could be defined for horses as well.
For each horse the cortisol value increased significantly during the behavioural test. A remarkable difference of the cortisol values assessed in the first and second test, indicates a learning effect: The behavioural test led to a significantly lower stress reaction in the second week.
Depending on the proportions of unstable regulation processes during and after the situations of strain, four types of regulation (Balzer u. Hecht 1996) can be defined: the Control-, Cope-, Compensate- and Non-cope-type.
Using the activation of the sympathetic and parasympathetic nervous system four vegetative stress types could be determined: Sympathicotonic, Amphotonic, Indifferent Type and Vagotonic.
The stress reaction of the stallions in terms of cortisol level was quite individual. To compare the maximum increase the trend of each cortisol trajectory was analyzed. On the one hand correcting for the trend allowed a comparison of relative maxima, on the other hand the horses could be categorized into groups, according to the evolution of their cortisol level (cortisol progression groups): Tendency falling, stable or rising.
The number of samples was not considered to be sufficient in order to statistically assess some dependence among the different classifications of stress types. But to our point of view horses can be assigned to different stress types like humans. But it’s still difficult to judge the emotions of animals, because emotions are subjectively perceptible qualities dependent on many internal and external factors. The assignment of emotional behaviour to the chronopsychobiological regulation diagnosis (CRD) can’t be transferred from human to horse without further studies.
However, the CRD method could enable an interdisciplinary approach. Besides classic descriptive observations of behavior, the CRD could give further information about the coping capacity and the consequences for animal welfare in the assessment of stressful situations.

Abstract: We tested untrained horses (foals and breeding mares) in 3 different breeding centres. Horses were kept in a pasture during daytime in bigger groups (median 12, min: 6, max 35 / pasture) according to age, gender and breed (hungarian halfbred, hucul, arabian and thoroughbred). To measure their reactions to an unfamiliar person we conducted an active and a passive human test. In the active human test the test person (TP) approached a focal animal in the group from a predetermined direction: from their front, from their side (left or right) or from the rear. As TP reached the horse (of app. 0.5 m distance), she tried to pet the animal’s head. The TP always chose and approached a standing or a grazing horse (ie. those that were not walking, galloping, playing etc.). The horse’s reaction to the approaching human was scored 1-5. Score 1: the horse moved away and the TP could not even approach it within 0.5 m; Score 2: the horse made max. 2 steps away, but could be reached and petted; Score 3 and Score 4: the horse stood in its place but showed different signs of discomfort (head turn – Score 3; backing ears, tail slash – Score 4); Score 5: the horse stood and did not show any sign of discomfort or actively approached the TP. There was no significant difference in the horses’ reaction between approaching from their left or right side. Approaching from their front or from their side (left or right) did not differ significantly either. However, the odds of walking away from the TP (score 1 or 2) was 2.7 (Fisher-test, p=0.039) and 3.3 (p=0.012) times higher when TP approached from the rear compared to approaching from their front or from their side (left or right), respectively. In the passive human test the TP stood immobile for 4 minutes in 5 or 10 m far from the horses during their active (grazing) or inactive (standing idle during noon) period. Horses approached TP significantly sooner (general linear model, p=0.017) when she stood 5m distance (38 ±63 s) compared to 10m (97 ±52 s). The arrival of a second horse after the first horse approached the TP showed significant high correlation with the latency of the first horse arrival (Pearson correlation, r=0.96, p<0.001). The horses were less keen (p=0.008) to approach the human when they were tested in an inactive period (177 ±110 s) compare to active period (38 ±63 s).