Abstract: Pferdegerechte Haltungssysteme spielen bei der heutigen Nutzung des Freizeit- oder Sportpartners Pferd eine wichtige Rolle, da naturnahe Haltungsbedingungen nur in seltenen Fällen zu realisieren sind. Sämtliche Aufstallungsformen müssen als Kompromiss angesehen werden und bieten somit Vor- und Nachteile. Die vorliegende Untersuchung verfolgte den Zweck, die Stressbelastung von Pferden in verschiedenen Haltungssystemen zu erfassen und vergleichend zu beurteilen. Während der von Mai 2006 bis Juli 2007 durchgeführten Versuche wurden 24 zwei- bis dreijährige Hannoveranerstuten für jeweils 4 Wochen in insgesamt 6 verschiedenen Haltungsformen aufgestallt. Die Haltungsvarianten beinhalteten die Einzelbox (Variante 1), die Einzelbox mit einem frei zugänglichem Paddock (Variante 2), die gemeinsame Haltung von zwei Pferden in zwei Boxen und einem angeschlossenen frei zugänglichem Auslauf (Variante 3) und die Gruppenhaltung von 6 Pferden in einer Mehrraumauslaufhaltung (Variante 4 – 6). Die Haltungsvariante 4 differierte von den Varianten 5 und 6 durch seinen ungegliederten Liegebereich. In den Variante 5 und 6 wurde der Liegebereich der Gruppenhaltung durch eine über die halbe Breite reichende Trennwand in zwei Bereiche unterteilt. Die Trennwand befand sich in Haltungsvariante 5 im rechten Winkel an die Außenwand grenzend, während sie in Variante 6 an der der Stallgasse zugewandten Seite des Liegebereichs aufgestellt wurde. Um eine Vergleichbarkeit mit einem Reitpferd zu schaffen, wurden alle Pferde in allen Haltungssystemen täglich für circa eine Stunde in einer Freilaufanlage bewegt. Die Stressbelastung wurde mittels der Messung der Herzfrequenzvariabilität (Parameter pNN50 und SD1) und der Bestimmung fäkaler Cortisolmetaboliten erfasst. Zusätzlich wurden Videoauswertungen hinsichtlich der Beobachtung von Verhaltensauffälligkeiten in den Haltungsvarianten 1 und 2 durchgeführt. Die durchschnittlich niedrigste Stressbelastung erfuhren die Pferde durch die Haltungsvarianten 4 (pNN50: 46,32 %, SD1:158,58 ms, Cortisolmetaboliten: 21,01nmol/kg Kot) und 6 (pNN50: 47,1 %, SD1: 144,62 ms, Cortisolmetaboliten: 21,01 nmol/kg Kot). Die
141
Auswertung der pNN50- und Cortisolmetabolitenwerte ergab die größte Stressbelastung der Pferde in den Varianten 1 (pNN50: 42,81 %, SD1: 134,52 ms, Cortisolmetaboliten: 28,56 nmol/kg Kot) und 3 (pNN50: 42,41 %, SD1: 135,36, Cortisolmetaboliten: 28,60 nmol/kg Kot). Die Auswertung der SD1-Werte zeigte zusätzlich noch eine hohe Stressbelastung der Pferde in der Variante 5 (pNN50: 44,83 %, SD1: 119,24 ms, Cortisolmetaboliten: 27,18 nmol/kg Kot). Die Haltungsvariante 2 (pNN50: 45,77 %, SD1: 144,25 ms, Cortisolmetaboliten: 27,59 nmol/kg Kot) beziehungsweise die Varianten 2 und 5 (bei der Betrachtung der pNN50- und der Cortisolmetabolitenwerte) verursachten im Durchschnitt eine mittlere Stressbelastung. Teilweise waren die Unterschiede jedoch zu gering um die Signifikanzgrenze zu überschreiten. Die Betrachtung der einzelnen Pferde und der Pferdegruppen ergab große interindividuelle Unterschiede und deutliche gruppenspezifische Gemeinsamkeiten. Die Position eines Tieres in der Rangordnung hatte in diesen Untersuchungen bei der Betrachtung der Mittelwerte keinen Einfluss auf die Stressbelastung in Abhängigkeit der Haltungsvariante. Vielmehr zeigten sich auch hier deutliche individuelle Unterschiede in der Stressanfälligkeit und den Vorlieben der einzelnen Pferde bezüglich der verschiedenen Haltungssysteme. Die Analyse der Videoaufzeichnungen ergab, dass mehrere Pferde Kreisbewegungen in der Einzelbox ohne Auslauf (Variante 1) zeigten, während in der Variante 2 (Paddockbox) kein Pferd durch Kreisbewegungen auffiel. Andere Verhaltensauffälligkeiten oder gar Verhaltensstörungen wurden nicht beobachtet. Bei der Auswertung der Aufenthaltshäufigkeit und der Aufenthaltesdauer in den 4 Boxenquadranten zeigten sich einige Pferde sehr aktiv, was ein Hinweis auf eventuelle Unruhe oder Nervosität sein kann, während andere Pferde im Vergleich zum Gruppendurchschnitt sehr ruhig wirkten, da sie sich in der Box kaum bewegten und über lange Zeitabschnitte in einem Quadranten standen. Obwohl die Gruppenhaltung für die Mehrzahl der Pferde eine geringere Stressbelastung bedeutete und auch hinsichtlich des Bewegungs- und Sozialverhaltens am artgerechtesten einzustufen ist, sollte für jedes Pferd individuell unter Berücksichtigung seines Alters, seiner Rasse, seines Nutzungsgrades, aber vor allem seines Charakters und seiner Erfahrungen im Sozialverhalten ein passendes großzügig bemessenes Haltungssystem ermittelt werden, um
142
die durch das Haltungssystem ausgeübte Stressbelastung zu minimieren und das Wohlbefinden der Pferde zu steigern.

Abstract: Horses, and in particular sport horses, remain housed predominantly in single stalls. One of the main reported reasons is the fear that they will become agitated and injure themselves and thereby impair their performance if released in paddocks. The hour spent daily at work is also assumed to be sufficient to satisfy the horses' needs for locomotion. Growing scientific evidence shows that single stall housing has negative consequences on horses' welfare and that time for free movement is necessary. Our aim was to assess the feasibility of allowing sport horses used to staying permanently in their stall (except for 1 h riding/day) daily free time in a paddock and to evaluate its potential impact on their welfare using two behavioural reliable indicators (stereotypic behaviours and ear position), as well as selected blood parameters (blood cell count, oxytocin and serotonin concentrations). Two experiments were conducted on the same site. The first experiment evaluated sport horses' habituation to the novel situation of daily sessions in a paddock, and recorded welfare indicators in their stall before and during the experiment, comparing horses that were taken outdoors (experimental) and those that stayed in their stall (control). The second experiment evaluated the impact of this daily free time in a paddock on horses' welfare and its durability, focusing on positive indicators. Behavioural observations in paddocks showed that even horses that had never experienced free movement outside their stall habituated rapidly to this situation. The presence of hay in the paddock, may have speeded up habituation. Their restricted living conditions were associated with abnormalities in blood cell count that were not overcome during the time of daily paddock sessions but behavioural indicators showed that their welfare improved. In the second study, the experimental horses' welfare improved during the paddock release period, in particular their stereotypic behaviours decreased and oxytocin levels increased. No effects on serotonin concentrations could be evidenced. These effects were directly associated with being in paddock, as the indicators returned rapidly to their previous levels indicating compromised welfare when the paddock release sessions stopped. In conclusion, it can be recommended to release sport horses for free movement in paddocks as welfare is improved and subjective assessment by caretakers indicated minimal risks.

Abstract: A human-animal relationship can be developed through subsequent interactions, affected by the positive or negative emotional valence of the proceeding one. Horses implement a process of categorization to classify humans with whom they interact as positive, negative, or neutral stimuli by evaluating the kind of approach and the nature of the contact. In these terms, human-animal interactions are emotionally charged events, eliciting specific emotional states in both subjects involved. Although the human-horse relationship has been mainly investigated through behavioral analysis, physiological indicators are needed for a more objective assessment of the emotional responses. Heart rate variability (HRV) is a commonly used autonomic nervous system (ANS) correlate estimating the sympathovagal balance as a psychophysiological marker of emotion regulation in horses. We have assumed that long-term positive relationships with humans may have a positive and immediate impact on the emotional arousal of the horse, detectable, via ANS activity, during the interaction. We analyzed horses' heartbeat dynamics during their interaction with either familiar or unfamiliar handlers, applying a standardized experimental protocol consisting of three different conditions shifting from the absence of interaction to physical contact. The ANS signals were monitored through an innovative non-invasive wearable system, not interfering with the unconscious emotional response of the animal. We demonstrated that horses appeared to feel more relaxed while physically interacting (e.g., grooming on the right side) with some familiar handlers compared to the same task performed by someone unfamiliar. The shift of the sympathovagal balance toward a vagal predominance suggests that the horses experienced a decrease in stress response as a function not only of the handler's familiarity but also of the type of interaction they are experiencing. These results constitute the objective evidence of horses' capacity to individually recognize a familiar person, adding the crucial role of familiarity with the handler as a paramount component of human-animal interaction. Our rigorous methodological approach may provide a significant contribution to various fields such as animal welfare while further investigating the emotional side of the human-animal relationships.

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.