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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.
Preparing for and competing in the heat: the human perspective. This review provides an overview of the challenges that face man and horses when exercising in the heat. Some of the strategies that are used and are being developed for human athletes exercising in the heat are reviewed. There are many similarities between human and equine physiological responses to exercise in the heat; and equine exercise science may gain some useful insights from the training, fluid replacement and heat acclimatisation strategies used by human athletes. There are, however, some important differences that impact on the ability of horses to thermoregulate and to regulate flu...
Cryopreservation reduces the ability of equine spermatozoa to attach to oviductal epithelial cells and zonae pellucidae in vitro. Two bioassays were used to evaluate the interaction of fresh and cryopreserved equine semen with oviductal epithelial cells (OEC) and with the zona pellucida (ZP). Split ejaculates were either stored at room temperature or frozen and thawed. In experiment 1, progressive motility and membrane integrity were evaluated for each treatment. Fluorescent labeled spermatozoa were cocultured with monolayers of OEC for 30 minutes, and the number of sperm attached to OEC was counted by fluorescence microscopy and analysis of digitized images. Motility of spermatozoa attached to OEC was observed at 0.5, 3...
Clinical observations made in nonheat acclimated horses performing treadmill exercise in cool (20 degrees C/40%RH), hot, dry (30 degrees C/40%RH) or hot, humid (30 degrees C/80%RH) conditions. Four horses (H, J, N and M) undertook a treadmill competition exercise test (CET), designed to simulate the physiological and metabolic stresses of the Speed and Endurance phase of a 3-day-event, under 3 different environmental conditions: 20 degrees C/40% relative humidity (RH) (cool, dry [CD]: 2 sessions); 30 degrees C/40%RH (hot, dry [HD]) and 30 degrees C/80%RH (hot, humid [HH]) (Marlin et al. 1995). A number of subjective clinical observations were made at designated time points throughout the exercise test and initial recovery period including buccal mucous membrane colouration, capillar...
Causes of differences in respiration rate of hepatocytes from mammals of different body mass. Resting O2 consumption of hepatocytes isolated from mammals ranging in mass from 20-g mice to 200-kg horses decreases with increasing body mass. The substrate oxidation system increases in activity with increasing body mass and mitochondrial proton leak and phosphorylation system decrease in activity, resulting in a higher mitochondrial membrane potential in hepatocytes from larger mammals. The absolute rates of O2 consumption due to nonmitochondrial processes, substrate oxidation, mitochondrial proton leak, and the phosphorylation system decrease with increasing body mass. These decreases are...
Effects of shortening the steeplechase phase (phase B) of a 3-day-event. Thirty-four horses competing in the Endurance Test of a 3-day-event were divided into 3 groups: horses in Group 1 (n = 15) competing in a 3.5 min steeplechase phase; horses in Group 2 (n = 13) in a 3 min steeplechase phase (Phase B) and horses in Group 3 (n = 6) in a 2.5 min steeplechase phase. The shortening of Phase B was associated with a lengthening of Phase C so that the total distance of the event for all horses was 14,940 m. Bodyweight (BW) was measured and total body water (TBW) and water loss estimated. Blood samples were collected from the horses prior to the Endurance Test, at the e...
Variable-temperature study of the heme-reorientation process in equine myoglobin. The redistribution of the initially-formed myoglobin heme-insertion isomers from the initially formed 50/50 mixture to the equilibrium ratio of 90/10 has long been assumed to occur by one of two mechanisms, both of which require the rupture of the heme iron-protein bond (La Mar, G.N., Toi, H. and Krishnamoorthi, K. (1984) J. Am. Chem. Soc. 106, 6395-6401). In this study we compared the use of nuclear magnetic resonance and optical spectroscopic techniques as methods for studying the reorientation of heme within myoglobin. We found that kinetics determinations of the heme insertion isomer redis...
Equine colonic lipomatosis. No abstract available
Intestinal fibrosis and vascular remodeling in ten horses and two ponies. No abstract available
Preweaning diet and stall weaning method influences on stress response in foals. The stress response of foals during weaning was examined in terms of a behavioral protocol and the responses of plasma ascorbate, serum cortisol, and the serum cortisol response to an ACTH challenge. The experimental plan was a 2 x 2 factorial of two preweaning diets and two stall weaning methods. Dietary groups included foals raised on pasture supplemented with hay and a pelleted concentrate (PHC) and foals raised on pasture supplemented with hay only (PH). Stall weaning methods included foals placed in stalls singly or in pairs. Sex influences were also examined. The foals exhibited characte...
Subcutaneous mycetoma-like granuloma in a horse caused by Aspergillus versicolor. No abstract available
Molecular cloning of equine interleukin-1 alpha and -beta cDNAs. Equine interleukin-1 alpha (IL-1 alpha) and IL-1 beta were molecularly cloned to establish a basis for research on inflammatory and immune responses in the horse. Equine peripheral blood mononuclear cells (PBMC) were stimulated with lipopolysaccharide (LPS), and cDNA clones of equine IL-1 alpha and IL-1 beta covering the whole coding sequences were isolated from them. These equine IL-1 alpha and IL-1 beta clones contained open reading frames encoding 271 and 269 amino acids, respectively. The deduced amino acid sequence of equine IL-1 alpha showed 71.6% and 60.2% similarity with that of human ...
Effect of maturation and aging on material and ultrasonographic properties of equine superficial digital flexor tendon. Results of studies in human beings and other species have indicated that aging significantly influences the strength, modulus of elasticity, and energy storage ability of tendon. We wanted to determine the effects of aging on the material and ultrasonographic properties of equine superficial digital flexor (SDF) tendon. Ultrasonographic measurements of left forelimb SDF tendon cross-sectional area and mean echogenicity were made in 23 standing horses ranging in age from 2 to 23 years. All horses had not been in work for a minimum of 6 months prior to the study. After euthanasia, left forelimb ...
Thyroid, renal, and splanchnic circulation in horses at rest and during short-term exercise. Using radionuclide-labeled 15-microm-diameter microspheres injected into the left ventricle, we examined blood flow to the thyroid gland, adrenal glands, kidneys, and various gastrointestinal tract tissues in 9 healthy horses while they were standing quietly (rest) and during exercise at 2 work intensities (8 and 1 m/s). Hemodynamic measurements were made during steady-state conditions, as judged by the stability of heart rate as well as aortic, pulmonary, and right atrial pressures. The similarity of blood flow values for the left and the right kidneys during each of the 3 conditions indicate...
Relation between stallion sperm binding to homologous hemizonae and fertility. The hemizona assay (HZA) has been developed as a diagnostic test to predict the fertilisation potential of human spermatozoa. The aim of this study was to develop an HZA for stallion spermatozoa and to investigate a possible relationship between fertility and the outcome of the HZA in this species. Equine oocytes were obtained from ovaries collected at a slaughterhouse and by transvaginal, ultrasound-guided follicle aspiration. They were then denuded from cumulus cells and stored in salt solution at 4 degrees C until use. On the day of the experiments the oocytes were bisected, thus providing ...
Ultrasonographic cross-sectional area and mean echogenicity of the superficial and deep digital flexor tendons in 50 trained thoroughbred racehorses. Fifty Thoroughbred horses were examined. All horses had been in race training for a minimum of 4 months before examination and had worked at racing speed; 24 horses had raced. All horses were clinically sound at the time of examination. Ultrasonography was performed, using a 7.5-MHz transducer with built-in fluid offset. Videotaped images of the palmar soft tissue structures were obtained at 4, 8, 12, 16, 20 and 24 cm distal to the base of the accessory carpal bone (DACB). Images were digitized, and each image was calibrated. Values for cross-sectional area (CSA) and mean echogenicity (ME) wer...
Changes in skeletal muscle composition in response to swimming training for young horses. To investigate muscular adaptation to swimming training in young horses, 18 two-year-old Thoroughbred horses were trained in a program which included both running and swimming, and the changes in skeletal muscle composition during the training period were evaluated histochemically. The horses were divided into the following three groups; Group A, trained by running only: Group B, trained by running plus a gradual increase in swimming; Group C, trained by running plus constant swimming. In Groups B and C, fast twitch-low oxidative (FT) fibers tended to decrease, while fast twitch-high oxidative...
Molecular cloning of DNA for inhibin alpha-subunit from equine ovary. cDNA encoding equine inhibin alpha-subunit precursor protein was isolated from an equine ovarian cDNA library. For screening, the DNA probe was amplified by the RT-PCR using primers designed based on the rat inhibin alpha-subunit cDNA sequence. Out of 1.2 x 10(5) plaques screened, 19 positive clones were isolated, and one of these clones (Eq-alpha-11) contained a complete open reading frame encoding 367 amino acids. The similarity of the deduced amino acid sequences of both equine inhibin alpha-subunit precursor protein and the mature protein were greater than 80% to those of other six mammali...
Metalloproteinase activity has a role in equine chorionic girdle cell invasion. Chorionic girdle cells are a highly invasive subpopulation of trophoblast cells of the equine conceptus. By Day 35 (Day 0 = day of ovulation), cells of the chorionic girdle adhere to the uterine epithelium and begin to invade the endometrial wall. Invasive cells must attach to extracellular matrix proteins, secrete proteinases capable of degrading matrix, and migrate through the degraded matrix; invasion is largely dependent on the proteinase activity of the cells. The objective, therefore, was to develop an in vitro system to examine the mechanisms of equine chorionic girdle cell invasion thr...
Ventilatory and arterial blood gas tension adjustments to strenuous exercise in standardbreds. Five healthy, fit Standardbreds (mean +/- SEM, 490.4 +/- 15.0 kg, 4.0 +/- 0.5 years) were studied during a standardized test carried out on a treadmill. The test consisted of an 8-minute warm-up and a 9-minute exercise period (1 minute at 1.7, 4, 7, 8, 9, and 10 m/s; 2 minutes at 4 m/s; and a 1-minute walk at a 6% slope). Respiratory airflow, tidal volume (V(T)), and respiratory frequency (f) were continuously recorded, using 2 ultrasonic pneumotachographs connected to a face mask and mass spectrometer. Oxygen uptake, carbon dioxide output, and expired minute volume (V(E)) were obtained on a b...
M-mode ultrasonic assessment of equine fetal heart rate. Embryonic heart rate was studied during 87 examinations in 56 mares on Days 25 to 174 post ovulation. Real-time B-mode using a stopwatch and M-mode ultrasonography were compared. For analyses of heart rates, data were grouped into weeks or months. For the stopwatch and M-mode techniques, respectively, heart rates averaged 123 and 133 beats per minute during Month 1, peaked during Month 3 at 172 or 196 beats, then gradually decreased over the duration of the study to 126 and 130 beats during Month 6. There was a significant increase in heart rate from Months 1 to 2 and Months 2 to 3 and a signi...
An investigation of gram-negative tannin-protein complex degrading bacteria in fecal flora of various mammals. Gram-negative tannin-protein complex degrading bacteria (T-PCDB) were first isolated from animals except for the koala. The occurrence of T-PCDB in feces of 15 species of mammals with different feeding habits was investigated. T-PCDB occurred in 7 of 54 horses but they could not be isolated from other mammals tested. These T-PCDB comprised less than 0.1% of the facultative anaerobic microflora in horse feces and it was much less than that previously reported in koala feces ( > 60%). A total of 7 T-PCDB fecal isolates showed a range of phenotypic diversities. They were all Gram-negative rods...
Fertility control using intrauterine devices: an alternative for population control in wild horses. The purpose of this study was to develop a contraceptive method for feral horses. The feral horse population has increased significantly in recent years despite attempts to control numbers. As in most wild animal population control programs, contraceptive methods must be easy to apply, cause minimal disruption to the social structure and be fully reversible. In the present study, we tested the effectiveness of an intrauterine device (IUD) for fertility control in mares. Six mares were fitted with a silastic O-ring-shaped IUD on July 1 of Year 1. The IUD-treated mares were turned out with 12 no...
The unfolding thermodynamics of c-type lysozymes: a calorimetric study of the heat denaturation of equine lysozyme. The energetics of the temperature-induced unfolding of equine lysozyme was studied calorimetrically and compared with that of two structurally homologous proteins: hen egg white lysozyme and alpha-lactalbumin. The structure of each of these proteins is characterized by the presence of a deep cleft that divides the molecule into two regions called the alpha and beta domains. In equine lysozyme and alpha-lactalbumin the latter domain specifically binds Ca2+. It is shown that, in contrast to hen egg white lysozyme in which the alpha and beta domains unfold as a single cooperative unit, in equine ...
Suture sinus formation following closure of ventral midline incisions with polypropylene in three horses. Suture sinuses formed in 3 horses following closure of ventral midline incisions with size-2 polypropylene. Suture sinuses healed after the suture material was removed. Suture sinus formation following closure with polypropylene may be related to the suture material's mechanical, rather than its chemical, properties. If polypropylene is used to close the linea alba in horses, the amount of tissue incorporated in the suture loops, suture tension, and knot volume should be minimized to decrease the risk of suture sinus formation.
