Krueger, K., Marr, I., Dobler, A., & Palme, R. (2019). Preservation of fecal glucocorticoid metabolites and immunoglobulin A through silica gel drying for field studies in horses. conphys, 7(1).
Abstract: Non-invasive methods enable stress evaluation through measuring fecal glucocorticoid metabolites (FGMs), and immunoglobulin A (IgA) in the feces avoiding stressful blood drawing or stressful restraining of animals in the field. However, FGMs and IgA are mostly analysed in freshly frozen samples, which is difficult when fresh samples cannot be frozen immediately or frozen samples cannot be stored or transported. Good results were also derived from air-dried fecal samples, which are hampered by unstable air humidity in the field. These difficulties may be overcome, when drying of samples could be induced with colorless silica gel (SiO2) granules in a secure set-up, such as an air tight tube. We determined the speed of drying 1.5 g of a fresh fecal sample from six horses on air and on silica gel. Furthermore, FGMs and IgA were analysed in differently stored subsamples from 12 horses: in frozen fecal samples, in air- or silica gel-dried samples stored for 1 day and for 7 days, and in wet fecal samples kept in a tube at room temperature for 7 days. FGM levels remained stable in feces dried on air or on silica gel for 7 days, whereas IgA quantities showed a significant loss. Under field conditions, when freezing or transporting the frozen samples is not possible and humidity hampers air drying, drying samples on silica gel in air tight tubes appears to be very helpful and reliable for analysing FGMs.
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Byström, A., Clayton, H. M., Hernlund, E., Rhodin, M., & Egenvall, A. (2020). Equestrian and biomechanical perspectives on laterality in the horse. Comp. Exerc. Physiol., 16(1), 35–45.
Abstract: It has been suggested that one of the underlying causes of asymmetrical performance and left/right bias in sound riding horses is laterality originating in the cerebral cortices described in many species. The aim of this paper is to review the published evidence for inherent biomechanical laterality in horses deemed to be clinically sound and relate these findings to descriptions of sidedness in equestrian texts. There are no established criteria to determine if a horse is left or right dominant but the preferred limb has been defined as the forelimb that is more frequently protracted during stance and when grazing. Findings on left-right differences in forelimb hoof shape and front hoof angles have been linked to asymmetric forelimb ground reaction forces. Asymmetries interpreted as motor laterality have been found among foals and unhandled youngsters, and the consistency or extent of asymmetries seems to increase with age. Expressions of laterality also vary with breed, sex, training and handling, stress, and body shape but there are no studies of the possible link between laterality and lameness. In a recent study of a group of seven dressage horses, a movement pattern in many ways similar to descriptions of sidedness in the equestrian literature, e.g. one hind limb being more protracted and placed more laterally than the other, has been documented. The role of innate laterality versus painful conditions, training, human handedness and simply habit remains to be determined. Understanding the biomechanical manifestations of laterality in healthy horses, including individual variation, would yield a potential basis for how laterality should be taken into account in relation to training/riding and rehabilitation of lameness.
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Voigtlaender-Schnabel, S., Vogel, L., Greiner, B., Wiezorek, S., Schuette, P., Solmsen, E. - H., et al. (2022). Reactions of horses to wildlife and livestock guarding dogs. CDPNews, 24, 49–58.
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Freitas, J., Lagos, L., & Álvares, F. (2021). Horses as prey of wolves. CDPnews, 23, 1–9.
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Lagos, L., & Blanco, P. (2021). Testing the use of dogs to prevent wolf attackson free ranging ponies in Iberia? CDPnews, 23, 20–27.
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Lagos, L., & Bárcena, F. (2022). How to reduce wolf predation on wild ponies in Galicia? CDPNews, 24, 24–31.
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Lema, F. J., Ribeiro, S., & Palacios, V. (2022). Observations of wolves hunting fee-ranging horses in Iberia. CDPNews, 24, 1–9.
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Solmsen, E. - H., Bathen, M., Grüntjens, T., Hempel, E., Klose, M., Krüger, K., et al. (2021). Protecting horses against wolves in Germany. CDPNews, 23.
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Murphy, J., & Arkins, S. (2006). Laterality and visuo-spatial ability in the equine: Functional measures of sport horse selection? BSAP Occasional Publication, 35, 159–170.
Abstract: Laterality in any organism or species can be manifest as morphological, sensory and functional degrees of asymmetry such as hemispheric dominance, handedness or sidedness and other motor functional behaviours and as such is equally important in equitation. The influence of the horses' sex on both the direction and the degree of the laterality was explored within and between 4 experimental procedures in the 1st study. The findings showed that the direction, but not the degree of idiosyncratic motor preference in the horses was strongly sex-related. Male horses exhibited significantly more left lateralized responses and female horses exhibited significantly more right lateralized responses. Visuo-spatial ability is also likely to be important in the performance horse. In many species, moderate to large differences in visuo-spatial ability have been reported between the sexes, with superior visuo-spatial ability being reported in males of all species investigated to date. As no known studies had addressed visuo-spatial ability in the equine, the objective of the 2nd study, was to determine if visuo-spatial ability differed between male and female horses. The results produced the first behavioural demonstration of superior visuo-spatial ability in male horses, similar to that reported in other species. There is evidence to suggest that visuospatial ability and motor laterality are associated with cerebral hemispheric asymmetry and may be intrinsically linked. Brain development and laterality have also been associated with hair patterning, and, in a 3rd study we attempted to identify predictors of lateral bias in motor behaviour in horses. We investigated the relationship between the direction of facial hair whorl rotation and the incidence/direction of laterality in the horse. The findings suggest that direction of facial hair whorl rotation may be a useful indicator of lateralised motor behavioural preferences in the horse. We then attempted to establish if laterality was evident at birth in a 4th study, where we explored if neonatal foals exhibited lateralised patterns during and immediately post the birthing process that were correlated with their facial hair whorl patterns. The results showed a significant association between the sex of the foal and the choice of foreleg presented initially during 2nd stage parturition. Significantly more colt foals led with the left foreleg and significantly more filly foals led with the right foreleg than expected purely by random and the behaviour was correlated with facial hair whorl patterns. The findings also suggest that lateralisation in the horse is determined in utero as has also been shown in humans. Comparisons of wholly intact male and female horses are warranted as they might elucidate additional linkages between motor behaviour, visuo-spatial ability and brain organisation and development in the horse. Further research in this area could lead to more appropriate competition conditions (better fence design/construction on cross-country tracks) and so eliminate unnecessary levels of risk associated with many equestrian sports.
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Fisher, J., & Hinde, R. A. (1994). The opening of milk bottles by birds. British Birds, (42), 347–357.
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