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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.
Geometric properties of equine metacarpi. Paired equine metacarpals were harvested, cleaned and sectioned transversely every 20 mm, and the bone geometry analyzed with a computer program. The cross-sectional area is largest in the middle third of the bone, and tapers off at either end. The principal axes are typically within 15 degrees of the anatomical axis, with the distal end rotated internally relative to the proximal end. At midshafts the bending stiffness in the antero-posterior plane is about 2/3 of the stiffness in the medio-lateral plane. The torsional stiffness is highest proximally. The equine third metacarpal appears to be...
Genetics of four plasma protein loci in Equus przewalskii: new alleles at the prealbumin, postalbumin and transferrin loci. This paper reports genetic variation at the prealbumin (Pr), postalbumin (Pa) and transferrin (Tf) loci in Equus przewalskii found using thin layer isoelectric focusing and an amphoteric separator. The method resolves all three loci plus serum esterase (Es) on a single gel, and typing of all four loci is readily achieved. In addition to the esterase alleles previously reported by Fisher & Scott (1979), five alleles were found at the Pr locus, three at the Pa locus and six at the Tf locus. Analysis of several mating types confirms inheritance is autosomal and codominant for all four loci.
Equine marker genes: polymorphism for plasminogen. Polymorphism for two autosomal alleles of equine plasminogen, PLG1 and PLG2, was demonstrated in plasma by isoelectric focusing and immunofixation, with a goat anti-human plasminogen antibody. The frequency of PLG2 was 0.16 in 150 Standardbreds, 0.20 in 96 Thoroughbreds, and 0.39 in 32 Shetland ponies. No evidence for linkage of PLG with any of 13 marker loci was found.
Studies on prolactin 48: isolation and properties of the hormone from horse pituitary glands. Isolation of prolactin from equine pituitary glands has been described. It has a potency of 42 IU/mg in the pigeon crop-sac test and consists of 199 amino acids. The hormone has only four half-cystine residues in contrast to other mammalian prolactins which have six residues. From NH2-terminal sequence analysis and amino acid composition of cyanogen bromide fragments, the NH2-terminal disulfide loop is missing in the equine prolactin molecule. Circular dichroism spectra indicate that the alpha-helical content of equine prolactin appears to be lower (50%) than that found in the ovine hormone (6...
S-adenosylhomocysteine hydrolase activity in horses, Equus cabalus, with severe combined immunodeficiency. 1. Activities of S-adenosylhomocysteine (AdoHcy) hydrolase were measured in tissues of horses with severe combined immunodeficiency. No decrease in activity of the enzyme was detected.
2. The activity in erythrocytes was 14.2 ± 9.2 nmol AdoHcy formed/min/g hemoglobin and in fibroblasts it was 28.0 ± 7.9 nmol AdoHcy formed/min/108 cells.
3. Km values were obtained for hemolysates (0.77 μM) and for fibroblast lysates (0.59 μM).
4. Effects of 2′-deoxyadenosine on enzyme inactivation were studied.
Seasonal effects on ovarian follicular development in pony mares. To define ovarian follicular kinetics in the equine ovary during anestrus and the breeding season, the follicular population of pony mares was investigated at mid-anestrus and at the beginning and end of the breeding season. There was a clear effect of season on the exit of reserve (primordial and initiated) follicles since at the beginning of the breeding season we noticed a higher mitotic index for the smaller preantral follicles, leading to an accumulation of small and medium antral follicles. In contrast, the ovaries sampled during anestrus or at the end of the breeding season were very si...
A reagin-like antibody in horse serum: 1. Occurrence and some biological properties. The demonstration of a reagin-like antibody against Culicoides pulicaris extract in the serum of horses and ponies affected with recurrent seasonal dermatitis (sweet itch) is reported. This antibody can confer Prauznitz-Küstner (P-K) sensitivity on homologous skin for up to 5 days and, like human IgE, is thermolabile and susceptible to 2-mercaptoethanol reduction. It is eluted on diethylaminoethyl dextran-52 anion exchange chromatography independently of IgG, IgG(T) and IgM, and its elution characteristics indicate similarity in net molecular charge to human IgE. The P-K response observed in ...
Genetic linkage between the loci for phosphohexose isomerase (PHI) and a serum protein (Xk) in horses. Genetic linkage between the equine loci for phosphohexose isomerase (PHI) and serum Xk protein was demonstrated by means of segregation data from three sire families. The recombination frequency was estimated from pooled data to be 0.23 +/- 0.02; a significant heterogeneity between sires for estimates of the recombination frequency was observed. No indication of linkage was detected between Xk and 14 other blood marker loci. Linkage between the Xk locus and the locus for soluble malic enzyme (ME1) has recently been reported in horses. An equine linkage group designated LG IV comprising the thr...
Factors in the control of feed intake of horses and ponies. Ponies are large nonruminant herbivores which are capable of utilizing the products of both enzymatic digestion in the small intestine and bacterial fermentation (volatile fatty acids, VFAs) in the cecum and large colon as sources of metabolizable energy. Recent studies have demonstrated that ponies utilize nutrient stimuli from both carbohydrate and fat digestion in the small intestine and VFAs in the cecum and large colon in the control of meal frequency. These animals, however, rely primarily upon oropharyngeal and external stimuli to control the size and duration of meals. This is perhaps ...
A study of physical demands in riding. Thirteen experienced riders and three elite riders underwent bicycle ergometer tests at submaximal and maximal workloads. Oxygen uptake, pulmonary ventilation and heart rate were also studied during riding at a walk, a trot and a canter. The mean maximal oxygen uptake of the experienced riders in the ergometer test (2.71 . min-1) was superior to the average maximal oxygen uptake of other groups of the same age and sex. The average oxygen uptake of the experienced riders in trot sitting was 1.701 . min-1, trot rising 1.681 . min-1 and in canter 1.801 . min-1. The experienced riders used at leas...
Pharmacology, pharmacokinetics, and behavioral effects of caffeine in horses. Caffeine (4 mg/kg) was given by rapid IV injection to 4 horses. Plasma concentrations of the drug peaked at 10 micrograms/ml and decreased rapidly at first, and then more slowly, with an apparent beta-phase half-life of 18.2 hours. Urinary concentrations of caffeine were remarkably consistent at about 3 times plasma values of the drug. Caffeine was detectable in both plasma and urine of the horses for up to 9 days after dosing. After oral administration, caffeine was absorbed poorly with an apparent bioavailability of 39%. Although blood concentrations of caffeine peaked rapidly after oral adm...
Linkage disequilibrium between the ELA and the A blood group systems in Standardbred horses. The linkage group formed by the ELA and A blood group system in horses was studied in American Standardbred horses. The distance between the ELA locus and the A blood group locus was measured as 1.61 centimorgans, observing only the haplotypes contributed by the sires. Strong linkage disequilibrium was found in pacing Standardbred horses for ELA-W1 with Aa, ELA-W5 with Ab and ELA-W10 with Ab. Linkage disequilibrium was apparent at both the population and family level. Among trotting Standardbred horses, linkage disequilibrium was found for ELA-W1 with Aa and for ELA-W10 with Ab. It was not pos...
Joint report of the First International Workshop on Lymphocyte Alloantigens of the Horse held 24-29 October 1981. Six equine lymphocyte alloantigen (ELA) specificities were defined by an international antiserum comparison test and workshop held in 1981. Twelve laboratories from four countries submitted 195 antisera for analysis. The antisera were exchanged among the 12 laboratories and tested in a standard lymphocyte microcytoxicity assay against the isolated lymphocytes at 1009 horses of several breeds. The data was pooled and analysed by a single computer analysis. The calculated chi 2 values of all cells with all antisera provided comparisons between antisera. Fifteen antisera clusters were formed by t...
Annular gap junctions of the equine hoof wall. Incidental to studies of keratinization of the equine hoof wall, annular gap junctions were found in the stratum spinosum of the intertubular horn of the stratum medium. Adjacent cells of the stratum spinosum showed extensive gap junctions, and often local invaginations of one cell into another were bound by gap junctions. It is proposed that these invaginations become detached from the cell surface to form the annular gap junctions. Formation of annular gap junctions may be a means of disposing of plasma membrane in response to changes in cell volume or shape occurring in keratinization. Inte...
Structural and functional properties of the non-muscle tropomyosins. The non-muscle tropomyosins (TMs), isolated from such tissues as platelets, brain and thyroid, are structurally very similar to the muscle TMs, being composed of two highly alpha-helical subunits wound around each other to form a rod-like molecule. The non-muscle TMs are shorter than the muscle TMs; sequence analysis demonstrates that each subunit of equine platelet TM consists of 247 amino acids, 37 fewer than for skeletal muscle TM. The major differences in sequence between platelet and skeletal muscle TM are found near the amino and carboxyl terminal ends of the proteins. Probably as the re...
Pyrimidine metabolism in peripheral and phytohemagglutinin-stimulated mammalian lymphocytes. 1. Activity of uridine kinase was very low in ovine lymphocytes and in those of some pigs. Lymphocytes of other pigs showed a significantly higher activity of this enzyme. Activity of uridine kinase in lymphocytes of man, horse and cattle was intermediate. 2. Activity of uridine phosphorylase was higher than that of uridine kinase with lymphocytes of all species. 3. Activity of uridine kinase in equine lymphocytes increases at PHA-stimulation and also in porcine lymphocytes with a low activity at the start of the culture. Activity of uridine kinase decreased in porcine lymphocytes with a high ...
Immunogenicity of equine herpesvirus type 1 (EHV1) and equine rhinovirus type 1 (ERhV1) following inactivation by betapropiolactone (BPL) and ultraviolet (UV) light. Some kinetic data on the inactivation of equine herpesvirus type 1 (EHV1) and equine rhinovirus type 1 (ERhV1) by betapropiolactone (BPL) and ultraviolet (UV) irradiation are reported. 0.25% BPL at 37 degrees C for 1 h reduced the titre of EHV1 by greater than 10(3 . 4) and of ERhV1 by greater than 10(4 . 1) TCID50/ml. UV irradiation (334 microW/cm2) produced similar reductions in titre after 2 min. These data were used as a basis for inactivating EHV1 and ERhV1 by the combined action of BPL and UV irradiation. Viruses were exposed to 0.1% BPL for 1 h at 4 degrees C with constant stirring, fol...
Limb mechanics as a function of speed and gait: a study of functional strains in the radius and tibia of horse and dog. Rosette strain gauges were attached to the midshaft of the radius and tibia of two horses and two dogs, which ran on a treadmill through their entire range of speed and gait. The relative magnitudes of the principal strains on the opposite cortices of each bone remained constant through the stance phase of the stride, and their orientation varied by a maximum of only 14 degrees through the entire speed range. The maximum strain rate increased linearly with speed, but the peak strain magnitude was also dependent upon the gait used, increasing incrementally by up to 59% at the transition from wa...
Correlation of parvalbumin concentration with relaxation speed in mammalian muscles. The physiological role of the Ca2+-binding protein parvalbumin in skeletal muscle has been investigated by measuring the parvalbumin content by HPLC in a variety of mammalian muscles, including man, and comparing the results with the respective muscle relaxation properties and fiber type compositions. The parvalbumin concentrations were highest in the skeletal muscles of the smallest animal investigated (mouse, gastrocnemius: 4.9 g/kg), which has the highest relaxation speed, and lowest in the larger animals (horse, deep gluteal muscle: less than or equal to 0.001 g/kg) and man (vastus, tricep...
