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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.
[Origin of the FSH + LH double activity of equine chorionic gonadotropin (eCG/PMSG)]. The LH and FSH activities of equine choriogonadotropin (eCG) have been compared in several species with those of the highly purified homologous pituitary gonadotropins. The molar FSH/LH activity ratio of eCG determined by RRA is 0.20 in the pig, 0.25 in the rat and 0 in the horse. These data demonstrate the LH monospecificity of eCG in its own species as it is the case for hCG. We have also shown that equine LH exhibited a FSH-activity similar to that of eCG in the pig and in the rat but not in the horse. In the female rat, the binding activity to FSH receptors and the in vitro FSH activity of...
Effects of environmental control on pulmonary function of horses affected with chronic obstructive pulmonary disease. The effects of environmental control on horses affected with chronic obstructive pulmonary disease was assessed by clinical examination and pulmonary function tests, ie, maximum change in intrathoracic pressure, tidal volume, minute volume, non-elastic work of breathing, dynamic compliance, inspiratory and expiratory flow rates and arterial blood gas analysis. A controlled environment (ie, bedding horses on shredded paper and feeding a complete cubed diet) caused symptomatic COPD affected horses to become asymptomatic within four to 24 days (mean +/- sd 8.4 +/- 4.8 days). When asymptomatic, th...
Blood-gas tensions and acid-base status in ponies during treadmill exercise. Blood-gas tensions and acid-base status were examined in 8 healthy grade ponies at rest (heart rate = 55 +/- 3 beats/min) and during moderate (fast trot; heart rate = 155 +/- 3 beats/min) and severe (gallop; heart rate = 218 +/- 7 beats/min) exercise performed on a treadmill. Arterial oxygen tension and hemoglobin-oxygen saturation of exercising ponies did not change from the resting values. Arterial oxygen content increased markedly during exercise, as a consequence of increased hemoglobin concentration. The total oxygen content, as well as the saturation of hemoglobin with oxygen in the mixe...
Survey of positive results from racecourse antidoping samples received at Racecourse Security Services’ Laboratories. A review of positive Jockey Club "dope tests" during the 12 years from 1970 to 1981 inclusive is presented and a comparison made with certain overseas racing authorities for varying periods between 1975 and 1981. Urinary pH of post race urine samples is predominantly acidic (although varying in a significant manner throughout the year) and thus favours excretion of the generally more potent basic drugs. The proportion of positive results was about the same in winners and non-winners, ie, one in 400 horses sampled. Drugs found fell mainly into four categories: methylxanthines; non-steroidal ant...
Isolation and partial characterization of equine alveolar macrophages. A device was constructed from an equine nasogastric tube, polyethylene tubing, and a 3-way stopcock and used to lavage the lungs of anesthetized ponies. The technique was safe and atraumatic in that 6.4 to 19.7 X 10(7) purified alveolar macrophages were removed from the lungs without harm to the ponies or contamination of the samples with blood. Studies of these highly purified cell suspensions revealed a mean viability of 85% as assessed by eosin dye exclusion with a mean recovery (+/- SD) of 12.5 +/- 4.8 X 10(7) pulmonary alveolar macrophages/pony.
Assessment of the sexual behavior of pregnant mares. Pregnant mares (N = 12) were observed with a stallion from early gestation until parturition for sexual behavior. Observations were conducted for 20 min per day for 5 days each month from September until July. No mares exhibited full estrus and no intromissions or ejaculations occurred at any time during the study. Social interactions such as male approach and female/female mutual grooming occurred with greater mean frequency or duration in some months of spring and fall than in winter months. (P less than 0.05). None of the recorded behaviors differed by month of gestation. In a comparison of...
Cerebrovascular response to acute decreases in arterial PO2. The purpose of these studies was to examine the time course of the cerebrovascular response to acute hypoxia in unanesthetized ponies. An electromagnetic flow transducer chronically placed on the internal carotid artery of the pony allowed continuous recording of internal carotid artery blood flow (ICBF) which has been shown to be representative of cerebral blood flow (CBF). The ponies were subjected to three levels of acute isocapnic hypoxia (PaO2 = 62, 44, and 39 mm Hg for hypoxia level I, II, and III, respectively), and the temporal and steady-state cerebrovascular response was examined. IC...
Differential sensitivity of human, avian, and equine influenza A viruses to a glycoprotein inhibitor of infection: selection of receptor specific variants. Human and animal (avian and equine) influenza A virus isolates of the H3 serotype exhibit marked differences in their ability to bind specific sialyloligosaccharide sequences that serve as cell surface receptor determinants (G. Rogers and J. Paulson, 1983, Virology 127, 361-373). Whereas human isolates of this subtype strongly agglutinate enzymatically modified human erythrocytes containing the terminal SA alpha 2,6Gal sequence, avian and equine isolates preferentially agglutinate erythrocytes bearing the SA alpha 2, 3Gal sequence. As shown in this report, a glycoprotein found in horse serum, ...
Studies on prolactin: conformational comparison of human, equine, and porcine pituitary prolactins. The conformations of human, equine, and porcine pituitary prolactins, as evidenced by various optical properties, have been compared. The alpha-helix contents of all three proteins are essentially identical to each other (60 +/- 5%), as well as to prolactins isolated from other mammalian species. Direct absorption (zero and second-order), difference absorption, fluorescence emission, and circular dichroism spectra suggest that the majority of tyrosine and tryptophan side chains in these three proteins exist in very similar microenvironments within the folded forms of the hormones. Thus, the ge...
Evidence that changes in LH pulse frequency may regulate the seasonal modulation of LH secretion in ovariectomized mares. To determine whether tonic LH secretion in ovariectomized mares is characterized by pulsatile release, frequent blood samples (every 15 min) were collected from 5 ovariectomized horse mares in nine 8-h periods between February and May. Mean serum LH concentrations increased 9-fold and were associated with a 4-fold increase in mean LH pulse frequency. These results provide the first evidence of pulsatile LH release in ovariectomized mares and suggest that the increasing daylengths of the spring months may increase serum LH by increasing LH pulse frequency.
Horse red blood cells frozen with 20% (w/v) glycerol and stored at -150 C for five years. When equine RBC were frozen with 20% (w/v) glycerol and stored at -150 C for as long as 5 years, there were no adverse effects on freeze-thaw or freeze-thaw-wash recovery or oxygen transport function. The manner in which the glycerol was added to, and removed from, the equine RBC was shown to be an important consideration in ensuring optimal freeze-thaw-wash recovery values.
Mechanical properties of equine hoof wall tissue. The mechanical properties of pigmented equine hoof wall tissue were determined for samples taken from the inner and outer portions of the stratum medium of the toe. Two properties, the modulus of elasticity and proportional limit, which are measures of the rigidity and yield point, respectively, of the tissue, were studied for samples compressed in 3 orthogonal directions. All samples tested were anisotropic. Inner wall samples were less rigid and had a lower yield point than outer wall samples.
Proton nuclear magnetic resonance studies of histidines in horse carbonic anhydrase I. The 250 MHz 1H-NMR spectrum of horse carbonic anhydrase I (or B) (carbonate hydro-lyase, EC 4.2.1.1) was measured as a function of pH under various conditions. Eight resonances corresponding to histidine C-2 protons and four resonances corresponding to histidine C-4 protons were identified and assigned to individual histidine residues in the enzyme molecule. Substantial similarities between horse and human carbonic anhydrases I were demonstrated. While the human enzyme has three titratable histidine residues in its active site, the horse enzyme has only two, His-67 in the human enzyme being re...
Observational study of “urine testing” in the horse and donkey stallion. Although "urine testing" is said to enable the male equid to assess the sexual status of the mare, there are no reports in the literature of any detailed study of this behavioural response of the stallion. Behavioural response to conspecific urine was studied in two horse stallions and one donkey stallion. The relevant nasopalatine anatomy is described. Events observed during urine testing included head, neck, lip, jaw, tongue movements, penile changes and nasal secretion. Nasal endoscopy indicated that the source of part of the nasal secretion was the secretory glands of the vomeronasal organ...
Spermatogenesis, testicular composition and the concentration of testosterone in the equine testis as influenced by season. The influence of season on spermatogenesis, testicular composition and the concentration of testosterone in the equine testis was evaluated using testes from 45 stallions. Testes were obtained through a commercial abbatoir during September, December-January, March and July. The weights of the testes, the tunica albuginea and testicular parenchyma and the proportion of the testicular parenchyma occupied by seminiferous tubules or interstitial tissue were similar during each season. How ever, diameter of the seminiferous tubules was greater in July than during other months of the study. In addit...
Changes of the fibrocartilage in navicular disease in horses. A histological and histochemical investigation of navicular bones. Histological and histochemical investigations of the fibrocartilage of facies flexoria from navicular bones of horses with navicular disease have shown alterations similar to those described in the hyaline articular cartilage in osteoarthritic joints.
Follicle stimulating hormone, luteinising hormone and progesterone concentrations in the blood of thoroughbred mares exhibiting single and twin ovulations. The concentrations of follicle stimulating hormone, luteinising hormone and progesterone were measured in serial blood samples taken throughout one or more oestrous cycles from 12 Thoroughbred mares, some of which exhibited single and others twin ovulations. The resulting profiles clearly demonstrated that no simple relationship exists between circulating gonadotrophin levels and subsequent ovulation rate in the mare. However, plasma progesterone concentrations during dioestrus are, as expected, higher following twin than single ovulations. The findings suggest that the underlying cause of twi...
[Various aspects of lactate production and disappearance in trotters during exertion]. Venous lactate concentrations were determined in standard-bred trotters following exercise of varying intensity to obtain a useful parameter in determining the working capacity of horses. After standard exercise, well-trained horses produced less lactate than did inadequately trained horses. During the post-exercise resting period, lactate disappeared faster from the blood in well-trained horses and young lightly trained horses than it did in poorly trained horses. Steady-state training resulted in lower lactate levels than those recorded after racing, whereas interval training resulted in the...
Volatile fatty acids and the role of the large intestine in the control of feed intake in ponies. The roles of volatile fatty acids (VFA) and of the large intestine in the control of feeding in ponies were investigated. Ponies with cecal fistulas were adapted to ad libitum access to pelleted feed. Treatment solutions were given as a bolus 15 min before the animals were allowed free access to feed after a 4-h fast. Each dose of VFA solution was tested in a crossover design with a water control. When the ponies were permitted to eat after the treatments, the latency to eat, first meal size, and duration and first intermeal interval were recorded. Feed intakes were measured at 3 and 18 h afte...
