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Topic:Equine Science
Equine Science encompasses the study of horses and their management, health, and performance. This field integrates various scientific disciplines such as biology, genetics, nutrition, physiology, and veterinary medicine to understand and improve the well-being and capabilities of horses. Areas of focus include equine anatomy, reproduction, behavior, and disease prevention. Research in equine science aims to enhance horse care, optimize training and performance, and address health challenges. This page compiles peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine science, providing insights into the latest advancements and methodologies in the field.
Magnetic motor evoked potentials in ponies. Magnetic stimulation of motor pathways was used to effect motor unit action potential recordings from forelimb and hindlimb muscles in unanesthetized ponies. Motor pathway conduction velocities to the forelimb and hindlimb were determined to be 53.8 +/- 9.6 m/s-1 and 63.4 +/- 8.3 m/s-1, respectively. This noninvasive technique will enable more precise evaluation of motor deficits in clinical patients than is possible with the neurological examination.
Equine cytochrome P450 aromatase exhibits an estrogen 2-hydroxylase activity in vitro. Aromatase (estrogen synthetase) is a steroidogenic enzyme complex which catalyzes the conversion of androgens to estrogens (termed aromatization). This enzyme was purified from adult equine testis to homogeneity by five chromatographic steps. The ability of purified and reconstituted equine aromatase to exhibit an estrogen 2-hydroxylase activity was tested and compared to testosterone aromatization. Enzymatic activities were assessed by tritiated water release from labelled estradiol and testosterone. Kinetic analysis of estradiol 2-hydroxylation showed an apparent K(m) of 23 microM and a V(ma...
Maintenance of equine articular cartilage explants in serum-free and serum-supplemented media, compared with that in a commercial supplemented medium. To evaluate the effects of a commercially defined, serum-free medium additive on equine articular cartilage explants, compared with effects of serum-free and serum-supplemented media. Methods: Articular cartilage from a 3-year-old, mixed breed horse euthanatized for reasons other than musculoskeletal disease or sepsis. Methods: Media were changed every 48 hours, and the glycosaminoglycan (GAG) content was determined in media collected at each time point. Glycosaminoglycan synthesis by explant chondrocytes, and residual GAG content of articular cartilage (as a measure of explant GAG loss) were ...
The effect of hole diameter on the torsional mechanical properties of the equine third metacarpal bone. The torsional monotonic structural material properties of equine metacarpi with or without, either a 5/16 inch or 3/8 inch diameter bicortical lateromedial middiaphyseal hole were assessed to determine the effect of a hole on metacarpal strength. Torsional stiffness was not significantly effected by the presence of a bicortical hole, whereas yield and failure angles, torques and energies of metacarpi with a hole were 51% to 97% of those of intact bones. Significant differences were not apparent for yield and failure mechanical properties between metacarpi with a 5/16 inch diameter hole and met...
Pulmonary blood flow distribution in standing horses is not dominated by gravity. Recent studies using microspheres in dogs, pigs and goats have demonstrated considerable heterogeneity of pulmonary perfusion within isogravitational planes. These studies demonstrate a minimal role of gravity in determining pulmonary blood flow distribution. To test whether a gravitational gradient would be more apparent in an animal with large vertical lung height, we measured perfusion heterogeneity in horses (vertical lung height = approximately 55 cm). Four unanesthetized Thoroughbred geldings (422-500 kg) were studied awake in the standing position with fluorescent microspheres injected ...
Quantification of normal head morphometry of stallion spermatozoa. The heads of stallion spermatozoa were analysed by computer automated sperm head morphometry and the morphometric values of the major subpopulations of sperm heads were assessed. The criteria for normal dimensions of stallion sperm heads are proposed based on the analysis of these measurements. Semen samples were collected from 10 fertile and 10 subfertile stallions, processed by a standard method, smeared onto microscope slides and stained using haematoxylin. At least 200 properly digitized sperm heads were analysed from each stallion. The measurements for length, width, area, perimeter and w...
Calcium buffering is required to maintain bone stiffness in saline solution. This work determined whether mineral dissolution due to prolonged testing or storage of bone specimens in normal saline would alter their elastic modulus. In one experiment, small pieces of equine third metacarpal bone were soaked in normal saline supplemented with varying amounts of CaCl2. Changing Ca ion concentrations in the bath were monitored and the equilibrium concentration was determined. In a second experiment, the elastic moduli of twenty 4 x 10 x 100 mm equine third metacarpal beams were determined non-destructively in four-point bending. Half the beams were then soaked for 10 days ...
Data on the prevalence of tapeworm infestations in horses in The Netherlands. The prevalence of tapeworm infestations was investigated in 70 horses slaughtered in the period February 1994-July 1994. Most horses were half-breed, young (1.5-3 years), and in good condition. They were bought for slaughter by dealers on local markets, and their treatment history was therefore unknown. Tapeworm infestations were seen in 16 horses (23%). Fifteen (21%) had an infection with Anoplocephala perfoliata. One horse had a single specimen of Paranoplocephala mamillana. The average number of A. perfoliata was 45 and the highest number was 508.
Pharmacokinetics of ketoprofen in the donkey (Equus asinus). The pharmacokinetic parameters of ketoprofen were determined in four donkeys after a single intravenous injection of a dose of 2.2 mg/kg body weight. The total body clearance (ClB) was 414.0 +/- 98.70 ml/h/kg (mean +/- SD), the volume of distribution at steady state (Vss) 263.10 +/- 55.43 ml/kg and the elimination half-life 1.30 +/- 0.75 h. These values were compared to those obtained in horses.
The structure of the community of strongyloid nematodes of domestic equids. The community structure exhibited by strongyloid nematodes from the large intestines of horses was examined using data from autopsies of 150 horses. Thirty-one species of nematodes were encountered, but they were not clearly divisible into core and satellite species. Multiple congeneric, consubfamilial and confamilial species were a prominent feature of the community and were more common than singleton infections. Multivariate analyses provided evidence of a stable community of helminths dominated by positive interactions but with few negative interactions, suggesting the absence of competitio...
Suppression of testicular function using two dose rates of a reversible water soluble gonadotrophin releasing hormone (GnRH) vaccine in colts. To investigate the effect of two dose rates (200 and 400 ng) of a gonadotrophin releasing hormone (GnRH) vaccine on testicular function. Methods: A vaccination dose rate experiment. Methods: Two injections were administered 4 weeks apart to six colts in each treatment group. To maintain immunosuppression until the end of the breeding season, a third injection was given if antibody titres fell below 1000. Results: Effective antibody titres were present for 12 to 27 weeks. Testosterone concentrations decreased from 2.22 to 0.31 nmol/L 6 weeks after primary vaccination. Androstenedione concentrat...
Methanogenesis in monogastric animals. Studies of methanogenic bacteria present in monogastric animals are still scarce. Methanogens have been isolated from faeces of rat, horse, pig, monkey, baboon, rhinoceros, hippopotamus, giant panda, goose, turkey and chicken. The predominant methanogen in all except the chicken and turkey is species of Methanobrevibacterium. The chicken and turkey harbour species of Methanogenium. In pig the population of methanogenic bacteria is more than 30 times as dense in the distal colon as in the caecum. This finding is in agreement with the finding that the rate of methane production is much higher in...
Minimal redistribution of pulmonary blood flow with exercise in racehorses. We determined the spatial distribution of pulmonary blood flow at rest and during increasing levels of exercise (34, 59, and 90% of maximal oxygen consumption) in Thoroughbred racehorses (n = 4) using 15-microns fluorescent microspheres. After the horses were killed, the lungs were flushed free of blood, removed, air-dried at total lung capacity, and sliced into isogravitational planes, which were sampled in a systematic fashion for three-dimensional reconstruction. The fluorescence was measured for quantification of blood flow. Mean pulmonary blood flow heterogeneity (expressed as a coefficie...
Tumour suppressor gene p53 in the horse: identification, cloning, sequencing and a possible role in the pathogenesis of equine sarcoid. The tumour suppressor protein p53 enhances the genetic stability of the cell and plays a critical role in tumour suppression. Equine p53 was analysed by sequencing exons 5 to 9, a region which includes most known mutations and all the mutational hotspots in the species that have been investigated. The fragment was amplified, cloned and sequenced from genomic and complementary DNA. A comparison of the predicted amino acid sequences between the horse and other species resulted in identities between 66 per cent with the clawed frog and 92 per cent with the cat. Using the single strand conformatio...
Use of the relationship between blood lactate and running speed to determine the exercise intensity of horses. Eight thoroughbred horses, trained for racing competition, were subjected to a standardised incremental speed test to determine the relationship between their blood lactate concentrations and running speed. Between 14 days before and 14 days after completing the standardised exercise test, the horses were timed for runs of 2000 to 6000 m. The blood lactate concentration after each run was measured and compared with the blood lactate concentration predicted from the individual horse's blood lactate-running speed relationship curve determined from the standardised exercise test. The relationship...
Age and breed differences in thyroid hormones, insulin-like growth factor (IGF)-I and IGF binding proteins in female horses. A survey with horses was conducted to determine whether plasma concentrations of triiodothyronine (T3), thyroxine (T4), insulin-like growth factor (IGF)-I and IGF binding proteins (IGFBP) change as horses grow, mature sexually, and age. Jugular blood was sampled from Standardbred fillies and mares at ages 0, 1, 7, and 14 d, at 1, 2, 4, 5, 6, and 9 mo, and at 5 to 8 and 16 to 22 yr (n = 5 to 18). In a second survey, we measured the same variables in eight breeds of horses with markedly different adult body sizes, from Miniatures to Friesians. Plasma T3, T4, and IGF-I were determined by radioimm...
Surgical materials and wound closure techniques. Recent innovations in surgical materials have helped to enhance wound healing and protect surgical wounds from infection. Materials such as polyglyconate have been evaluated in equine tissues and found efficacious. Other materials, such as poliglecaprone 25, appear to have qualities useful to equine surgery but are untested in equine tissues. Care must be taken to fully evaluate a new surgical material because its usefulness in equine tissues may not match that in human or laboratory animal tissues. Furthermore, use of disposable materials in surgery, although considered ideal for maintenance ...
Surface plasmon resonance studies of complex formation between cytochrome c and bovine cytochrome c oxidase incorporated into a supported planar lipid bilayer. II. Binding of cytochrome c to oxidase-containing cardiolipin/phosphatidylcholine membranes. Complex formation between horse heart cytochrome c (cyt c) and bovine cytochrome c oxidase (cco) incorporated into a supported planar egg phosphatidylcholine membrane containing varying amounts of cardiolipin (CL) (0-20 mol%) has been studied under low (10 mM) and medium (160 mM) ionic strength conditions by surface plasmon resonance (SPR) spectroscopy. Both specific and nonspecific modes of cyt c binding are observed. The dissociation constant of the specific interaction between cyt c and cco increases from approximately 6.5 microM at low ionic strength to 18 microM at medium ionic strength, ...
Should a doctor prescribe hormone replacement therapy which has been manufactured from mare’s urine? Many clinicians are experiencing consumer resistance to the prescription of equine HRT (that is hormone replacement therapy which has been manufactured from mare's urine). In this paper I consider the ethical implications of prescribing these preparations. I decide that patients should have a right to refuse such treatment but also ask whether a prescribing doctor should choose one preparation over another on moral grounds. I determine that there is prima facie evidence to suggest that mares may suffer and that prescription of equine HRT (instead of synthetic oestrogen-oestriol) would therefor...
Instrumentation and techniques in transendoscopic upper respiratory tract laser surgery. Transendoscopic laser surgery provides equine surgeons with a safe, reliable, and minimally invasive method of performing many surgical procedures in the upper respiratory tract. Although the Nd:YAG laser has proven efficacy, other newer lasers such as the diode and holmium: YAG lasers may prove to be useful tools for equine upper respiratory tract surgery. Long grasping forceps and a high quality fiberoptic or video endoscope are critical components necessary for performing transendoscopic laser surgery. For many of the most common upper respiratory tract abnormalities, a laryngotomy can be e...
[Wild horse or domesticated horse? Horse remains from the neolithic settlement in Pestenacker, Bavaria]. The bone finds from the neolithic settlement in Pestenacker (near Landsberg am Lech) date back to the second half of the 4th millennium BC (Altheim). Like in any other late neolithic horse bones, the question we have to deal with is whether they represent the remains of wild horse or early domestic horse, as we do not know for certain yet the date of the earliest domestic horses' occurrence in Middle Europe. The post pleistocene distribution of the wild horse is described. For a long time people thought that hardly any wild horses existed in post pleistocene Middle Europe any longer, due to th...
Effects of altered FIO2 on maximum VO2 in the horse. Although the horse is considered an elite athlete with a specific VO2max some 2-4 times higher than man, maximal O2 transport is compromised both by moderately severe arterial desaturation and by failure to extract all O2 from blood perfusing exercising muscle. This prompted the present study to ascertain whether correction of arterial desaturation would proportionally augment VO2max and, if so, would O2 extraction behave in a manner predicted by diffusional transport limitation. Six two year old thoroughbreds were exercised to VO2max on a treadmill each on three separate occasions breathing g...
Osteonal structure in the equine third metacarpus. In studying the flexural fatigue properties of the equine third metacarpal (cannon) bone, we previously found that the dorsal region was weaker monotonically, but more fatigue resistant, than the lateral region. Fatigue resistance was associated with fracture surfaces which demonstrated that secondary osteons had "pulled out" of the surrounding matrix; this never happened in lateral specimens. We therefore became interested in the osteonal structure of this bone, and began to study its birefringence patterns in circularly polarized light. We found that the predominant type of secondary osteon ...
