Vitale, V., Balocchi, R., Varanini, M., Sgorbini, M., Macerata, A., Sighieri, C., et al. (2013). The effects of restriction of movement on the reliability of heart rate variability measurements in the horse (Equus caballus). J. Vet. Behav., 8(5), 400–403.
Abstract: Analysis of heart rate variability (HRV) is a noninvasive approach for investigating the sympathovagal balance of the autonomic nervous system. In recent years, HRV has been increasingly evaluated in animal research. In horses, it has been suggested that basal resting conditions can be achieved by restraining them. The aim of this study was to verify how restriction of movement influences HRV i2n horses. Ten healthy standardbred mares were used to measure the electrocardiographic signal under 2 conditions: free to move in the stall and restrained in the stock. Results indicate that the restriction of movement is associated with increased nervous system sympathetic activity not consistent with resting conditions.
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Jankunis, E. S., & Whishaw, I. Q. (2013). Sucrose Bobs and Quinine Gapes: Horse (Equus caballus) responses to taste support phylogenetic similarity in taste reactivity. Behavioural Brain Research, 256, 284–290.
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.
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Lucidi, P., Bacco, G., Sticco, M., Mazzoleni, G., Benvenuti, M., Bernabò, N., et al. (2013). Assessment of motor laterality in foals and young horses (Equus caballus) through an analysis of derailment at trot. Physiol. Behav., 109, 8–13.
Abstract: The conflicting results regarding the study of motor laterality in horses may indicate that there does not exist a proper method to assess the degree and the direction of motor bias in these animals. Unfortunately, even less is known about the development of laterality in horses, and to what extent early manipulations can still exert their effects in adulthood. We propose a new method that can be easily applied at a very early age thus avoiding testing adult horses eventually biased by human handling and/or training. Forty-six horses (29 nine-month-old foals and 17 two-year old horses) were handled since birth bilaterally and housed in groups in wide areas. At the time of the analysis, in order to minimize environmental and sensorial disturbances, each horse was tested in a round pen individually or as dyad mother-foal. The ability/inability to properly execute a circle at trot was then recorded, assuming the direction of derailment, i.e. the cutting of the circle, as an indicator of motor bias. From the results of the study it is arguable that motor laterality in horses is acquired over time: in fact foals tested while their mothers were being subjected to longeing showed a higher percentage of ambidextrous animals, while two-year-old horses appeared biased toward the right (p<0.05). Results are discussed in the light of the scientific knowledge about equine biomechanics, taking into account horses' locomotion that leads to the advancement of the body mass through the activation of a kinetic chain that originates from the hindquarters.
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Benz, B., Benitz, B., Krueger, K., & Winter, D. (2013). Weniger Einstreu bei gleichem Komfort. Pferdezucht und Haltung, 1, 66–71.
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GONÇALVES DA SILVA, A., CAMPOS-ARCEIZ, A., & ZAVADA, M. S. (2013). On tapir ecology, evolution and conservation: what we know and future perspectives–part II. Integrative Zoology, 8(1), 1–3.
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Becker-Birck, M., Schmidt, A., Wulf, M., Aurich, J., von der Wense, A., Möstl, E., et al. (2013). Cortisol release, heart rate and heart rate variability, and superficial body temperature, in horses lunged either with hyperflexion of the neck or with an extended head and neck position. Journal of Animal Physiology and Animal Nutrition, 97(2), 322–330.
Abstract: Bringing the head and neck of ridden horses into a position of hyperflexion is widely used in equestrian sports. In our study, the hypothesis was tested that hyperflexion is an acute stressor for horses. Salivary cortisol concentrations, heart rate, heart rate variability (HRV) and superficial body temperature were determined in horses (n = 16) lunged on two subsequent days. The head and neck of the horse was fixed with side reins in a position allowing forward extension on day A and fixed in hyperflexion on day B. The order of treatments alternated between horses. In response to lunging, cortisol concentration increased (day A from 0.73 ± 0.06 to 1.41 ± 0.13 ng/ml, p < 0.001; day B from 0.68 ± 0.07 to 1.38 ± 0.13 ng/ml, p < 0.001) but did not differ between days A and B. Beat-to-beat (RR) interval decreased in response to lunging on both days. HRV variables standard deviation of RR interval (SDRR) and RMSSD (root mean square of successive RR differences) decreased (p < 0.001) but did not differ between days. In the cranial region of the neck, the difference between maximum and minimum temperature was increased in hyperflexion (p < 0.01). In conclusion, physiological parameters do not indicate an acute stress response to hyperflexion of the head alone in horses lunged at moderate speed and not touched with the whip. However, if hyperflexion is combined with active intervention of a rider, a stressful experience for the horse cannot be excluded.
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Hunt, G. R., Gray R.D., & Taylor, A. H. (2013). Why is tool use rare in animals? (Boesch C C. J. anz C, Ed.). Cambridge, MA.: Cambridge University Press.
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Figueroa, J., Solà-Oriol, D., Manteca, X., & Pérez, J. F. (2013). Social learning of feeding behaviour in pigs: Effects of neophobia and familiarity with the demonstrator conspecific. Appl. Anim. Behav. Sci., 148(1), 120–127.
Abstract: Social interactions facilitate animals learning of new features of their environment minimizing a trial and error process. It has been observed in some species that food cues can be acquired by one individual (the observer) from an animal model (demonstrator) due to social learning. Three experiments were performed to evaluate whether weaned piglets may show a preference for a flavoured feed following brief social interactions (30min) with an experienced demonstrator. After the social interaction between demonstrator and observer pigs, a 30-min choice test between the flavoured feed previously eaten by demonstrators (DEM-feed) and other flavoured feed (OTH-feed; Exp. 1 and 2) or a known unflavoured starter diet (Exp. 3) was performed with observer animals. Greater intake of DEM-feed occurred when demonstrators and observers were from the same pen (Exp. 1) or from the same litter (Exp. 2), but not when observers and demonstrators were unfamiliar with each other (Exp. 1). Observers also preferred flavours previously eaten by the demonstrator over their unflavoured diet already known. Social interactions with a conspecific pig that had a recent experience with a flavoured feed enhanced the preference for that feed and could even override neophobia to a new feed. The familiarity of conspecific demonstrators plays a key role in social learning of new feed cues probably due to selective exploration involving closer snout-to-snout contacts with kin conspecifics.
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Murray, L. M. A., Byrne, K., & D’Eath, R. B. (2013). Pair-bonding and companion recognition in domestic donkeys, <em>Equus asinus</em>. Appl. Anim. Behav. Sci., 143(1), 67–74.
Abstract: Pair and social bonding has been documented in various taxa, where pair formations are often described as being driven by kinship or sexual motivation. However, pair-bonding between unrelated individuals where sexual motivation is not a factor is not well documented. Many social relationships and pair-bonds between members of a dyad are facilitated by each individual's ability to recognise their partner using cues which are characteristic of that particular individual. The aims of this study were i) to investigate the existence of pair-bonding in domestic donkeys and ii) to determine whether members of a dyad could recognise their companion during a Y-maze recognition test. Subjects were 55 unrelated donkeys (38 gelded males, 15 females) in seven groups of mixed or same sex, comprising 4?14 individuals. Spatial proximity (nearest-neighbour) was observed three times a day over a 22-day period. Using a simulation approach based on observed data to generate randomised nearest-neighbour matrices, the statistical significance of social relationships was estimated. Of these, 42 (79.2%) were involved in significantly (p<0.05) non-random nearest-neighbour relationships, most of which were reciprocal pair relationships. Based on the spatial data, 24 of the donkeys which had shown significant reciprocal nearest-neighbour preferences for one individual (companion) were then used in a Y-maze recognition test in which they were presented with a choice of their companion and either a familiar donkey from the same group or an unfamiliar donkey from a different group. Donkeys? spatial location in the Y-maze demonstrated a preference for their companion versus familiar (one sample Wilcoxon signed rank test, W=239, p=0.002) or unfamiliar donkeys (W=222, p=0.041). These results verify anecdotal evidence from donkey handlers that donkeys often form pair-bonds, and show that reciprocal social preference and recognition are the basis of these. Pair-bond formation and companionship among donkeys have potential implications for their management, husbandry and welfare.
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Leblanc, M. - A. (2013). The mind of the horse, An Introduction to Equine Cognition. Harvard, MA: Harvard University Press.
Abstract: Horses were first domesticated about 6,000 years ago on the vast Eurasian steppe extending from Mongolia to the Carpathian Mountains. Yet only in the last two decades have scientists begun to explore the specific mental capacities of these animals. Responding to a surge of interest in fields from ethology to comparative psychology and evolutionary biology, Michel-Antoine Leblanc presents an encyclopedic synthesis of scientific knowledge about equine behavior and cognition. The Mind of the Horse provides experts and enthusiasts alike with an up-to-date understanding of how horses perceive, think about, and adapt to their physical and social worlds.
Much of what we know—or think we know—about “the intelligence of the horse” derives from fragmentary reports and anecdotal evidence. Putting this accumulated wisdom to the test, Leblanc introduces readers to rigorous experimental investigations into how horses make sense of their world under varying conditions. He describes the anatomical and neurophysiological characteristics of the horse’s brain, and offers an evolutionary perspective by comparing these features with those of other species. A horseman himself, Leblanc also considers the opinions of renowned riding masters, as well as controversies surrounding the extraordinary powers of the horse’s mind that have stirred in equestrian and scientific circles.
Although scientists understand more today about how horses think than at any time in our species’ long acquaintance with these animals, much remains in the dark. The Mind of the Horse brings together the current state of equine research and will likely stimulate surprising new discoveries.
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