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Gorgasser I., Tichy A., & Palme R. (2007). Faecal cortisol metabolites in Quarter Horses during initial training under field conditions[Messung der Kortisolmetaboliten im Pferdekot während der Grundausbildung von 2jährigen Quarter Horses]. Wien. Tierärztl. Mschr. – Vet. Med. Austria, 94, 226–230.
Abstract: The first month of training of a young horse is suspected to be stressful, but the endocrine responses to initial training are unknown. Therefore in our study a total of 40 Quarter Horses (QH), all at the age of almost 2 years, were followed during the first 30 days of their training. During this time faecal samples were collected twice daily and faecal cortisol metabolites (FCM) were measured. Baseline values of FCM ranged between 1.3 and 20.1 (median: 6.7) ng/g faeces. No differences in FCM values between days of training were found. Mares showed the highest values. Significant diurnal variations were observed in mares (p=0.035) and stallions (p=0.003), but not in geldings (p=0.282). As in this study adrenocortical activity was not increased during initial training, horses seem to cope very well with this new situation. The results of our large-scale study provide basic physiological data about initial training. This gives additional input in an emotional debate about animal welfare aspects of first time handling and training of horses.
Abbreviations: 11,17-DOA = 11,17-dioxoandrostanes; EIA = Enyzme Immunoassay; FCM = faecal cortisol metabolites; GC = glucocorticoids; HPA-axis = hypothalamic-pituitary-adrenocortical-axis; QH = Quarter Horses [Das Einreiten eines jungen Pferdes steht unter Verdacht belastend zu sein. Bisher gibt es aber keine Veröffentlichungen über endokrine Vorgänge während dieser Phase. Mit der vorliegenden Studie wurde überprüft, ob Pferde aufgrund physischer und psychischer Belastungen während des Trainings höhere Konzentrationen an Kortisolmetaboliten im Kot (FCM) aufweisen. Es wurden dazu 40 Quarter Horses im Alter von 2 Jahren während der ersten 30 Tage der Grundausbildung des Westernreitens beobachtet und ihre FCM Werte gemessen. Während dieser Zeitspanne wurden täglich morgens und abends Kotproben der Pferde genommen. Die Basalwerte der FCM Konzentration variierten zwischen 1,3 und 20,1 (Median: 6,7) ng/g Kot, wobei Stuten die höchsten Werte hatten. Signifikante Unterschiede während der einzelnen Trainingstage konnten nicht festgestellt werden. In der Tagesrhythmik wurden signifikante Unterschiede bei Stuten (p=0,035) und bei Hengsten (p=0,003), jedoch nicht bei Wallachen (p=0,282) ermittelt. In dieser Studie konnte keine erhöhte Aktivität der Nebennierenrinde im Verlauf der Grundausbildung eines Pferdes im Westernreitstil festgestellt werden. Das legt nahe, dass Pferde mit dieser neuen, zeitlich kurz andauernden Situationen gut zurechtkommen. Unsere Studie wurde an einer großen Anzahl von Tieren unter Feldbedingungen durchgeführt. Sie bietet daher eine gute Datenbasis über Belastungen während des Einreitens. Damit liefert sie einen zusätzlichen Beitrag zu einer mitunter emotional geführten Debatte über tierschutzrelevante Aspekte bei der Grundausbildung von Pferden.] |
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Palme, R., Touma, C., Arias, N., Dominchin, M.N., & Lepschy, M. (2013). Steroid extraction: Get the best out of faecal samples. Wien Tierärztl Monat – Vet Med Austria, 100, 238–246.
Abstract: Faecal steroid hormone metabolites are becoming increasingly popular as parameters for reproductive functions and stress. The extraction of the steroids from the faecal matrix represents the initial step before quantification can be performed. The steroid metabolites present in the faecal matrix are of varying polarity and composition, so selection of a proper extraction procedure is essential. There have been some studies to address this complex but often neglected point. Radiolabelled steroids (e.g. cortisol or progesterone) have frequently been added to faecal samples to estimate the efficiency of the extraction procedures used. However, native, unmetabolized steroids are normally not present in the faeces and therefore the results are artifi- cial and do not accurately reflect the actual recoveries of the substances of interest. In this respect, recovery experiments based on faecal samples from radiometabolism studies are more informative. In these samples, the metabolite content accurately reflects the mixture of metabolites present in the given species. As a result, it is possible to evaluate different extraction methods for use with faecal samples. We present studies on sheep, horses, pigs, hares and dogs that utilized samples containing naturally metabolized, 14C-labelled steroids. We recommend extracting faecal steroids by simply suspending the faeces in a high percentage of a primary alcohol (for glucocorticoid metabolites 80% aqueous methanol proved best suited for virtually all mammalian species tested so far). Not only does the procedure significantly increase the total amount of recovered radioactivity, it also increases the percentage of unconjugated metabolites, which are more likely to be recognized by the antibodies used in various immunoassays. The advantages of this extraction procedure are clear: it is very easy to use (no evaporation step is needed), it yields high recoveries and variation based on the extraction procedure is reduced to a minimum.
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Veeckman J,. (1978). Afwijkend sexuell gedrag van een dekhengst. Vlaams Diergeneeskundig Tijdschr, 47, 267–273.
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Timney, B., & Keil, K. (1999). Local and global stereopsis in the horse. Vision Res, 39(10), 1861–1867.
Abstract: Although horses have laterally-placed eyes, there is substantial binocular overlap, allowing for the possibility that these animals have stereopsis. In the first experiment of the present study we measured local stereopsis by obtaining monocular and binocular depth thresholds for renal depth stimuli. On all measures, the horses' binocular performance was superior to their monocular. When depth thresholds were obtained, binocular thresholds were several times superior to those obtained monocularly, suggesting that the animals could use stereoscopic information when it was available. The binocular thresholds averaged about 15 min arc. In the second experiment we obtained evidence for the presence of global stereopsis by testing the animals' ability to discriminate between random-dot stereograms with and without consistent disparity information. When presented with such stimuli they showed a strong preference for the cyclopean equivalent of the positive stimulus with the real depth. These results provide the first behavioral demonstration of a full range of stereoscopic skills in a lateral-eyed mammal.
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Sivak, J. G., & Allen, D. B. (1975). An evaluation of the “ramp” retina of the horse eye. Vision Res, 15(12), 1353–1356.
Abstract: Using a rapid freezing and sectioning technique, the distance between the lens and retina of the horse eye was measured. There is no indication of a ramp retina that could serve accommodation. The pupil axis of the eye coincides with the maximum lens to retina distance. The changes in the lens-retina distance are greater below the axis than above it. Calculations were made of refractive power of the horse eye from measurements of curvature and refractive indices of the ocular tissues. These calculations agree both qualitatively and quantitatively with retinoscopic measurements on live horses. Both show that the refractive state shifts in the direction of hyperopia above and below the axis and that this shift is greater below the axis than above it. Some dynamic accommodative ability in the living eye was observed.
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Timney, B., & Keil, K. (1992). Visual acuity in the horse. Vis. Res., 32(12), 2289–2293.
Abstract: We assessed the ease with which horses could learn visual discriminations and measured their resolution acuity. We trained three horses to press their noses against one of two large wooden panels to receive a small food reward. Following training on a series of two-choice discrimination tasks, resolution acuity was measured. Although there was some variability between animals, the best acuity obtained was 23.3 c deg-1. Within the margin of error imposed by limited anatomical data, the obtained values are consistent with predictions based on retinal ganglion cell density estimates and posterior nodal distance/axial length ratios. They suggest that the resolution acuity of the horse is limited by ganglion cell density in the temporal portion of the narrow visual streak.
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Cilnis, M. J., Kang, W., & Weaver, S. C. (1996). Genetic conservation of Highlands J viruses. Virology, 218(2), 343–351.
Abstract: We studied molecular evolution of the mosquito-borne alphavirus Highlands J (HJ) virus by sequencing PCR products generated from 19 strains isolated between 1952 and 1994. Sequences of 1200 nucleotides including portions of the E1 gene and the 3' untranslated region revealed a relatively slow evolutionary rate estimated at 0.9-1.6 x 10(-4) substitutions per nucleotide per year. Phylogenetic trees indicated that all HJ viruses descended from a common ancestor and suggested the presence of one dominant lineage in North America. However, two or more minor lineages probably circulated simultaneously for periods of years to a few decades. Strains isolated from a horse suffering encephalitis, and implicated in a recent turkey outbreak, were not phylogenetically distinct from strains isolated in other locations during the same time periods. Our findings are remarkably similar to those we obtained previously for another North American alphavirus, eastern equine encephalomyelitis virus, with which Highlands J shares primary mosquito and avian hosts, geographical distribution, and ecology. These results support the hypotheses that the duration of the transmission season affects arboviral evolutionary rates and vertebrate host mobility influences genetic diversity.
Keywords: Alphavirus/*genetics; Alphavirus Infections/transmission/veterinary/virology; Amino Acid Sequence; Animals; Base Sequence; Conserved Sequence; Disease Outbreaks; Encephalitis, Viral/veterinary/virology; *Evolution, Molecular; Horses; Molecular Sequence Data; Phylogeny; RNA, Viral/genetics; Sequence Alignment; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid; Turkeys; Variation (Genetics)/*genetics
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Connor, R. J., Kawaoka, Y., Webster, R. G., & Paulson, J. C. (1994). Receptor specificity in human, avian, and equine H2 and H3 influenza virus isolates. Virology, 205(1), 17–23.
Abstract: The receptor specificity of 56 H2 and H3 influenza virus isolates from various animal species has been determined to test the relevance of receptor specificity to the ecology of influenza virus. The results show that the receptor specificity of both H2 and H3 isolates evaluated for sialic acid linkage specificity and inhibition of hemagglutination by horse serum correlates with the species of origin, as postulated earlier for H3 strains based on a limited survey of five human, three avian, and one equine strain. Elucidation of the amino acid sequence of several human H2 receptor variants and analysis of known sequences of H2 and H3 isolates revealed that receptor specificity varies in association with an amino acid change at residues 228 in addition to the change at residue 226 previously documented to affect receptor specificity of H3 but not H1 isolates. Residues 226 and 228 are leucine and serine in human isolates, which preferentially bind sialic acid alpha 2,6-galactose beta 1,4-N-acetyl glucosamine (SA alpha 2,6Gal), and glutamine and glycine in avian and equine isolates, which exhibit specificity for sialic acid alpha-2,3-galactose beta-1,3-N-acetyl galactosamine (SA alpha 2,3Gal). The results demonstrate that the correlation of receptor specificity and species of origin is maintained across both H2 and H3 influenza virus serotypes and provide compelling evidence that influenza virus hosts exert selective pressure to maintain the receptor specificity characteristics of strains isolated from that species.
Keywords: Amino Acid Sequence; Amino Acids/genetics; Animals; Carbohydrate Sequence; Chick Embryo; Hemagglutinin Glycoproteins, Influenza Virus; Hemagglutinins, Viral/genetics; Influenza A virus/*metabolism; Molecular Sequence Data; Receptors, Virus/*metabolism; Species Specificity; Viral Envelope Proteins/genetics
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Makarov, V. V., & Bakulov, I. A. (1975). [Zoopathogenic arboviruses, their systematics and ecology]. Veterinariia, (11), 39–41.
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Spengler M.I., & Rasia M. (2001). Influence of Plasma Proteins on Erythrocyte Aggregation in Three Mammalian Species. Vet.Res.Comm, 25(7), 591–599.
Abstract: The aggregation capacity of human erythrocytes lies between that of the non-aggregating bovine erythrocytes and the remarkably aggregating equine ones. As the ability to aggregate is attributed to cell factors and the composition of the plasma proteins, the role that plasma proteins play in the aggregation process in these three species was studied. Washed erythrocytes were suspended in phosphate-buffered saline (PBS; pH 7.4, 300 mOsm/L) plus polyvinylpyrrolidone (PVP) in a suitable concentration to obtain an average intensity of aggregation (control media). The superimposed effect of replacing 80% of the medium by either autologous plasma, serum or albumin solution was studied. The plasma proteins appeared to enhance aggregation by human and equine erythrocytes, but impaired this process in bovine erythrocytes. Some evidence was obtained supporting the existence of serum factors capable of reducing aggregation of erythrocytes in cattle and it was concluded that the non-aggregating behaviour of bovine erythrocytes may be due to the cells interacting particularly with the macromolecules in the serum.
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