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Marr, I., Stefanski, V., & Krueger, K. (2022). Lateralität – ein Indikator für das Tierwohl?[Laterality – an animal welfare indicator?]. Der Praktische Tierarzt, 103(12/2022), 1246–12757.
Abstract: Ein gutes Tierwohl definiert sich nicht nur durch die Abwesenheit von Stressindikatoren, sondern auch durch das Vorhandensein von Indikatoren, die auf ein gutes Wohlergehen hinweisen. So können stressbedingte Erkrankungen vermieden werden. Zur Bestimmung des Tierwohls bei Pferden wurde daher untersucht, inwieweit sich die sensorische Lateralität (einseitiger Gebrauch von Sinnesorganen) und die motorische Lateralität (einseitiger Gebrauch von Gliedmaßen) als einfach, schnell und kostengünstig zu erhebende Parameter eignen. Hierzu werden neben aktueller Literatur auch die eigenen Untersuchungsergebnisse zusammenfassend dargestellt. Die nach außen sichtbar werdende sensorische und motorische Lateralität sind das Resultat der cerebralen Lateralisierung. Dies beinhaltet nicht nur die Aufgabenteilung beider Gehirnhälften für ein effizienteres Aufnehmen und Speichern von Informationen, sondern sie steht auch in Verbindung mit der Entstehung und Verarbeitung von Emotionen, die maßgeblich am Wohlergehen eines Lebewesens beteiligt sind. Kurzzeitige Stressoren führen zu einer Erregung, die je nach Erfahrungen mit positiven oder negativen Emotionen in Verbindung steht. Emotionen helfen dem Organismus dabei, zu überleben. Andauernde negative Emotionen durch regelmäßige oder anhaltende negative Ereignisse führen zu Stress und reduzieren die Erwartung positiver Ereignisse (negativer cognitive Bias). Das Tier ist im Wohlergehen beeinträchtigt. Jüngst zeigte insbesondere die Messung der motorischen Lateralität Potenzial als Indikator für lang anhaltenden und chronischen Stress, denn gestresste Pferde, deren Stresshormonlevel stark ansteigt, zeigen einen zunehmenden Gebrauch der linken Gliedmaßen über einen längeren Zeitraum. Weiterhin zeigen erste Messungen einen Zusammenhang zwischen einer linksseitigen motorischen Lateralität und einer reduzierten Erwartung positiver Ereignisse (negativer cognitive Bias). Zusammen mit der sensorischen Lateralität, die in einer akuten Stressphase ebenso eine Linksverschiebung zeigt und somit als Indikator für Kurzzeitstress gilt, kann eine generelle, vermehrte Linksseitigkeit auch einen Hinweis auf erhöhte Emotionalität und Stressanfälligkeit sein. Eine sich steigernde Linksseitigkeit bedeutet eine präferierte Informationsverarbeitung durch die rechte Gehirnhälfte, die beispielsweise reaktives Verhalten, starke Emotionen und Stressantworten steuert. Es stellte sich jedoch heraus, dass wie bei allen Stressindikatoren auch in der Lateralitätsmessung ein Vergleichswert aus einer vorangegangenen Messung notwendig ist, denn nur Veränderungen zum häufiger werdenden Gebrauch der linken Seite können auf Stress bei Pferden hindeuten und die parallele Erhebung weiterer Parameter, wie zum Beispiel das Verhalten oder Stresshormone, können die Aussage der Lateralität bekräftigen.
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Marr, I., Farmer, K., & Krueger, K. (2018). Evidence for Right-Sided Horses Being More Optimistic than Left-Sided Horses. Animals, 8(12), 219.
Abstract: An individual's positive or negative perspective when judging an ambiguous stimulus (cognitive bias) can be helpful when assessing animal welfare. Emotionality, as expressed in approach or withdrawal behaviour, is linked to brain asymmetry. The predisposition to process information in the left or right brain hemisphere is displayed in motor laterality. The quality of the information being processed is indicated by the sensory laterality. Consequently, it would be quicker and more repeatable to use motor or sensory laterality to evaluate cognitive bias than to perform the conventional judgment bias test. Therefore, the relationship between cognitive bias and motor or sensory laterality was tested. The horses (n = 17) were trained in a discrimination task involving a box that was placed in either a “positive” or “negative” location. To test for cognitive bias, the box was then placed in the middle, between the trained positive and negative location, in an ambiguous location, and the latency to approach the box was evaluated. Results indicated that horses that were more likely to use the right forelimb when moving off from a standing position were more likely to approach the ambiguous box with a shorter latency (generalized linear mixed model, p < 0.01), and therefore displayed a positive cognitive bias (optimistic).
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Wolter, R., Stefanski, V., & Krueger, K. (2018). Parameters for the Analysis of Social Bonds in Horses. Animals, 8(11), 191.
Abstract: Social bond analysis is of major importance for the evaluation of social relationships in group housed horses. However, in equine behaviour literature, studies on social bond analysis are inconsistent. Mutual grooming (horses standing side by side and gently nipping, nuzzling, or rubbing each other), affiliative approaches (horses approaching each other and staying within one body length), and measurements of spatial proximity (horses standing with body contact or within two horse-lengths) are commonly used. In the present study, we assessed which of the three parameters is most suitable for social bond analysis in horses, and whether social bonds are affected by individual and group factors. We observed social behaviour and spatial proximity in 145 feral horses, five groups of Przewalski�s horses (N = 36), and six groups of feral horses (N = 109) for 15 h per group, on three days within one week. We found grooming, friendly approaches, and spatial proximity to be robust parameters, as their correlation was affected only by the animals� sex (GLMM: N = 145, SE = 0.001, t = �2.7, p = 0.008) and the group size (GLMM: N = 145, SE < 0.001, t = 4.255, p < 0.001), but not by the horse breed, the aggression ratio, the social rank, the group, the group composition, and the individuals themselves. Our results show a trend for a correspondence between all three parameters (GLMM: N = 145, SE = 0.004, t = 1.95, p = 0.053), a strong correspondence between mutual grooming and friendly approaches (GLMM: N = 145, SE = 0.021, t = 3.922, p < 0.001), and a weak correspondence between mutual grooming and spatial proximity (GLMM: N = 145, SE = 0.04, t = 1.15, p = 0.25). We therefore suggest either using a combination of the proactive behaviour counts mutual grooming and friendly approaches, or using measurements of close spatial proximity, for the analysis of social bonds in horses within a limited time frame.
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Burn, C. C. (2011). A Vicious Cycle: A Cross-Sectional Study of Canine Tail-Chasing and Human Responses to It, Using a Free Video-Sharing Website. Plos One, 6(11), e26553.
Abstract: Tail-chasing is widely celebrated as normal canine behaviour in cultural references. However, all previous scientific studies of tail-chasing or 'spinning' have comprised small clinical populations of dogs with neurological, compulsive or other pathological conditions; most were ultimately euthanased. Thus, there is great disparity between scientific and public information on tail-chasing. I gathered data on the first large (n = 400), non-clinical tail-chasing population, made possible through a vast, free, online video repository, YouTube[TM]. The demographics of this online population are described and discussed. Approximately one third of tail-chasing dogs showed clinical signs, including habitual (daily or 'all the time') or perseverative (difficult to distract) performance of the behaviour. These signs were observed across diverse breeds. Clinical signs appeared virtually unrecognised by the video owners and commenting viewers; laughter was recorded in 55% of videos, encouragement in 43%, and the commonest viewer descriptors were that the behaviour was 'funny' (46%) or 'cute' (42%). Habitual tail-chasers had 6.5+/-2.3 times the odds of being described as 'Stupid' than other dogs, and perseverative dogs were 6.8+/-2.1 times more frequently described as 'Funny' than distractible ones were. Compared with breed- and age-matched control videos, tail-chasing videos were significantly more often indoors and with a computer/television screen switched on. These findings highlight that tail-chasing is sometimes pathological, but can remain untreated, or even be encouraged, because of an assumption that it is 'normal' dog behaviour. The enormous viewing figures that YouTube[TM] attracts (mean+/-s.e. = 863+/-197 viewings per tail-chasing video) suggest that this perception will be further reinforced, without effective intervention.
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de Oliveira, K., Soutello, R. V. G., da Fonseca, R., Costa, C., de L. Meirelles, P. R., Fachiolli, D. F., et al. (2015). Gymnastic Training and Dynamic Mobilization Exercises Improve Stride Quality and Increase Epaxial Muscle Size in Therapy Horses. Journal of Equine Veterinary Science, 35(11), 888–893.
Abstract: The objective was to evaluate the efficacy of gymnastic training (GYM) and dynamic mobilization exercises (DMEs) on stride length (SL) and epaxial muscle size in therapy horses. Nine cross-bred hippotherapy horses that performed three, 25-minute therapeutic riding sessions per week throughout the study period were randomly assigned to three experimental groups: a control group in which the horses were sedentary with no additional physical activity; a group that performed DMEs; and a group that performed both DMEs and additional GYM including pelvic tilting, backing, turning in small circles, and walking over a raised rail to strengthen the abdominal and pelvic stabilizer muscles. The exercises were performed 3Â days per week for 3Â months, with evaluations at the start and end of the study. Stride quality was assessed by measuring SL and tracking distance (TD). Epaxial muscle size was monitored by ultrasonographic measurement of m. longissimus dorsi (LD) thickness and m. multifidi (MM) cross-sectional area. Paired t tests were used to compare within groups across time, and between groups were detected using analysis of variance with Tukey post hoc test. When walking at 1.3Â m/s, SL and TD at walk increased significantly (P < .05) in horses subjected to GYM. Thickness of LD did not change in any group, but cross-sectional area of MM increased significantly by 3.55Â cm2 (DME) and 3.78Â cm2 (GYM). It was concluded that GYM training improved stride quality and DME-stimulated MM hypertrophy which has been shown to improve intervertebral joint stability in other species.
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Houpt, K., Marrow, M., & Seeliger, M. (2000). A preliminary study of the effect of music on equine behavior. Journal of Equine Veterinary Science, 20(11), 691–737.
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Piro, M., Benjouad, A., Karom, A., Nabich, A., Benbihi, N., El Allali, K., et al. (2011). Genetic Structure of Severe Combined Immunodeficiency Carrier Horses in Morocco Inferred by Microsatellite Data. J. Equine Vet. Sci., 31(11), 618–624.
Abstract: A total of 17 microsatellite deoxyribonucleic acid loci used routinely for horse parentage control were used to evaluate genetic diversity among normal Arabian horses and severe combined immunodeficiency (SCID) carrier Arabian horses (ArS) and normal Arab-Barb horses and SCID carrier Arab-Barb horses (ArbeS). On the basis of the genotype of 186 horses, mean allelic diversity was estimated as 6.82, 5.53, and 6.7059 in normal Arabian horses, ArS, and for both groups of Arab-Barb horses, respectively. Five specific alleles were observed in ArS and ArbeS, with one common with ArS at HMS6, whereas five alleles common between ArS and ArbeS had a high frequency. Expected and observed heterozygosity showed great heterogeneity in the population studied and were similar or higher when compared with other studies on Arabian horses. Coefficient of gene differentiation Gst of Nei associated with Nei's genetic distance and multivariate correspondence analysis indicated a possible differentiation between the studied populations when analyzed separately according to breed. Probability of assignment of a horse to a specific group was assessed using a full and partial Bayesian approach. In all, 80.6% of Arab horses and 78.2% of Arab-Barb horses were assigned properly with a partial Bayesian test, which provided better results than the full one. These findings will be useful for identification of SCID carrier horses by using the microsatellite deoxyribonucleic acid loci used routinely for horse parentage control in our laboratory.
Keywords: Scid; Arab horses; Arab-Barb horses; Microsatellite; Dna; Genetic structure
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Whiten, A., Horner, V., Litchfield, C. A., & Marshall-Pescini, S. (2004). How do apes ape? Learn. Behav., 32(1), 36–52.
Abstract: In the wake of telling critiques of the foundations on which earlier conclusions were based, the last 15 years have witnessed a renaissance in the study of social learning in apes. As a result, we are able to review 31 experimental studies from this period in which social learning in chimpanzees, gorillas, and orangutans has been investigated. The principal question framed at the beginning of this era, Do apes ape? has been answered in the affirmative, at least in certain conditions. The more interesting question now is, thus, How do apes ape? Answering this question has engendered richer taxonomies of the range of social-learning processes at work and new methodologies to uncover them. Together, these studies suggest that apes ape by employing a portfolio of alternative social-learning processes in flexibly adaptive ways, in conjunction with nonsocial learning. We conclude by sketching the kind of decision tree that appears to underlie the deployment of these alternatives.
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Whiten, A., Custance, D. M., Gomez, J. C., Teixidor, P., & Bard, K. A. (1996). Imitative learning of artificial fruit processing in children (Homo sapiens) and chimpanzees (Pan troglodytes). J Comp Psychol, 110(1), 3–14.
Abstract: Observational learning in chimpanzees and young children was investigated using an artificial fruit designed as an analog of natural foraging problems faced by primates. Each of 3 principal components could be removed in 2 alternative ways, demonstration of only one of which was watched by each subject. This permitted subsequent imitation by subjects to be distinguished from stimulus enhancement. Children aged 2-4 years evidenced imitation for 2 components, but also achieved demonstrated outcomes through their own techniques. Chimpanzees relied even more on their own techniques, but they did imitate elements of 1 component of the task. To our knowledge, this is the first experimental evidence of chimpanzee imitation in a functional task designed to simulate foraging behavior hypothesized to be transmitted culturally in the wild.
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Rhodin, M., Johnston, C., Holm, K. R., Wennerstrand, J., & Drevemo, S. (2005). The influence of head and neck position on kinematics of the back in riding horses at the walk and trot. Equine Vet J, 37(1), 7–11.
Abstract: REASONS FOR PERFORMING STUDY: A common opinion among riders and in the literature is that the positioning of the head and neck influences the back of the horse, but this has not yet been measured objectively. OBJECTIVES: To evaluate the effect of head and neck position on the kinematics of the back in riding horses. METHODS: Eight Warmblood riding horses in regular work were studied on a treadmill at walk and trot with the head and neck in 3 different predetermined positions achieved by side reins attached to the bit and to an anticast roller. The 3-dimensional movement of the thoracolumbar spine was measured from the position of skin-fixed markers recorded by infrared videocameras. RESULTS: Head and neck position influenced the movements of the back, especially at the walk. When the head was fixed in a high position at the walk, the flexion-extension movement and lateral bending of the lumbar back, as well as the axial rotation, were significantly reduced when compared to movements with the head free or in a low position. At walk, head and neck position also significantly influenced stride length, which was shortest with the head in a high position. At trot, the stride length was independent of head position. CONCLUSIONS: Restricting and restraining the position and movement of the head and neck alters the movement of the back and stride characteristics. With the head and neck in a high position stride length and flexion and extension of the caudal back were significantly reduced. POTENTIAL RELEVANCE: Use of side reins in training and rehabilitation programmes should be used with an understanding of the possible effects on the horse's back.
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