Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
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.
Testicular endocrine function, seasonality and semen quality of the stallion. To gain further information on gonadal function of the stallion, concentrations of testicular steroids in blood plasma (bpl) and seminal plasma (spl) and their distribution in the ejaculate were determined. Blood and semen samples from a total of 11 stallions were collected from November to July. Estrone (E1), estrone sulfate (E1S), estradiol-17beta (E2beta) and testosterone (T) were determined in bpl and spl, and in addition androstenedione (A), dehydroepiandrosterone (DHEA) and 5alpha-dihydrotestosterone (5alpha-DHT) were measured in spl. At certain points of time, aliquots of an ejaculate w...
Morphological study on pigmented cells in the horse testis. One of the most attractive characteristics of a horse testis is the change of the weight during development. As the testicular weight changes and the number of Leydig cells decreases, pigments appear in interstitial tissues. In the present study, the characteristics of the pigments found in the interstitial tissues were examined histochemically and ultrastructurally. Specific stainings indicated that the pigmented granules showed almost all of the histological and histochemical characteristics of ceroid or ceroid-like pigment. The cells showed positive reaction for acid phosphatase while the p...
Influence of chromium tripicolinate on growth and glucose metabolism in yearling horses. Thoroughbred and Quarter Horse yearlings (n = 24; 335+/-7 d of age) were used in a 112-d feeding trial to determine whether chromium (Cr) supplementation would alter growth, development, and energy metabolism of growing horses on high-concentrate diets. The horses were assigned at random within breed and gender subgroups to one of four treatment groups: A) basal concentrate; B) basal plus 175 microg of Cr/kg concentrate; C) basal plus 350 microg of Cr/kg concentrate; and D) basal plus 700 microg of Cr/kg concentrate. Chromium was provided via Cr tripicolinate (Prince Agri Products, Quincy, IL)...
Equine sweating responses to submaximal exercise during 21 days of heat acclimation. This study examined sweating responses in six exercise-trained horses during 21 consecutive days (4 h/day) of exposure to, and daily exercise in, hot humid conditions (32-34 degrees C, 80-85% relative humidity). On days 0, 3, 7, 14, and 21, horses completed a standardized exercise test on a treadmill (6 degrees incline) at a speed eliciting 50% of maximal O(2) uptake until a pulmonary artery temperature of 41.5 degrees C was attained. Sweat was collected at rest, every 5 min during exercise, and during 1 h of standing recovery for measurement of ion composition (Na(+), K(+), and Cl(-)) and swe...
Anatomic, radiographic and physiologic comparisons of the internal carotid and maxillary artery in the horse. The anatomy of the internal carotid and maxillary arteries was examined using angiography, subtraction angiography and arterial cast preparations in three horses. Subtraction angiography was superior to angiography in demonstrating the anatomy of the occipital, external ophthalmic, ethmoidal and palatine arteries. In three horses manipulation of the internal carotid and occipital arteries during angiography resulted in vasospasm which prevented filling of these vessels with contrast. Direct arterial blood pressure measurements of the maxillary artery impinging on the guttural pouches was measu...
Exercise affects the mechanical properties and histological appearance of equine articular cartilage. Dorsal carpal osteochondral injury is a major cause of reduced performance in horses undergoing high-intensity training. It was hypothesised that the mechanical behaviour and histology of cartilage are influenced by the intensity of exercise and by location within a joint. Relationships between histology and mechanical behaviour were identified in 2-year-old horses undergoing 19 weeks of high-intensity treadmill training or low-intensity exercise and then compared between groups. Dorsal and palmar test sites were identified on radial, intermediate, and third carpal articular surfaces after eut...
Behavior of stabled horses provided continuous or intermittent access to drinking water. To compare quantitative measures and clinical assessments of behavior as an indication of psychologic well-being of stabled horses provided drinking water continuously or via 1 of 3 intermittent delivery systems. Methods: 22 Quarter Horse (QH) or QH-crossbred mares and 17 Belgian or Belgian-crossbred mares (study 1) and 24 QH or QH-crossbred mares and 18 Belgian or Belgian-crossbred mares (study 2). Methods: Stabled horses were provided water continuously or via 1 of 3 intermittent water delivery systems in 2 study periods during a 2-year period. Continuous 24-hour videotaped samples were used...
Effects of prior exercise on muscle metabolism during sprint exercise in horses. The effect of warm-up exercise on energy metabolism and muscle glycogenolysis during sprint exercise (Spr) was examined in six fit Standardbred horses exercised at 115% of maximal O(2) consumption (VO(2 max)) until fatigued, 5 min after each of three protocols: 1) no warm-up (NWU); 2) 10 min at 50% of VO(2 max) [low-intensity warm-up (LWU)]; and 3) 7 min at 50% VO(2 max) followed by 45-s intervals at 80, 90, and 100% VO(2 max) [high-intensity warm-up (HWU)]. Warm-up increased (P < 0.0001) muscle temperature (T(m)) at the onset of Spr in LWU (38.3 +/- 0.2 degrees C) and HWU (40.0 +/- 0. 3 de...
The equine herpesvirus 2 E1 open reading frame encodes a functional chemokine receptor. Several herpesviruses contain open reading frames (ORFs) that encode potential homologs of eucaryotic genes. Equine herpesvirus 2 (EHV-2) is a gammaherpesvirus related to other lymphotropic herpesviruses such as herpesvirus saimiri and Epstein-Barr virus. The E1 ORF of EHV-2, a G protein-coupled receptor homolog, shows 31 to 47% amino acid identity with known CC chemokine receptors. To investigate whether E1 may encode a functional receptor, we cloned the E1 ORF and expressed it in stably transfected cell lines. We report here the identification of the CC chemokine eotaxin as a functional liga...
Equine synteny mapping of comparative anchor tagged sequences (CATS) from human Chromosome 5. Comparative anchor tagged sequences (CATS) from human Chromosome 5 (HSA5) were used as PCR primers to produce molecular markers for synteny mapping in the horse. Primer sets for 21 genes yielded eight horse-specific markers, which were mapped with the UC Davis horse-mouse somatic cell hybrid panel into two synteny groups: UCD14 and UCD21. These data, in conjunction with earlier human chromosome painting studies of the horse karyotype and synteny mapping of horse microsatellite markers physically mapped by FISH, confirm the assignment of UCD21 to ECA21 and suggest that UCD14 is located on ECA14...
Metabolic functions of L-carnitine and its effects as feed additive in horses. A review. L-carnitine, a betaine derivative of beta-hydroxybutyrate, is found in virtually all cells of higher animals and also in some microorganisms and plants. In animals it is synthesized almost exclusively in the liver. Two essential amino acids, i.e., lysine and methionine serve as primary substrates for its biosynthesis. Also required for its synthesis are sufficient amounts of vitamin B6, nicotinic acids, vitamin C and folate. The first discovered ergogenic function of L-carnitine is the transfer of activated long-chain fatty acids across the inner mitochondrial membrane into the mitochondrial m...
Locomotor response to exercise in relation to plasma lactate accumulation and heart rate in Andalusian and Anglo-Arabian horses. To establish the effect of the locomotor pattern on heart rate (HR) and plasma lactate (LA), 28 horses, 18 Andalusian (AN) and 10 Anglo-Arabian (AA), aged 3-4 years, were studied. After a warm-up period, the horses performed a four-step test at 5, 6, 7 and 8 m/s, covering 1000 m at each velocity. HR was monitored, LA was analysed at rest and after each workload, and images were filmed. The locomotor parameters determined were stride duration (SD), frequency (SF) and length (SL), step and bipedal support durations, stance (restraint and propulsion) and swing phase durations, and stride vertical...
Measurement for breath concentration of hydrogen and methane in horses. This study concerns the establishment of a simple testing method for breath concentration of hydrogen and methane in horses. Twenty-eight healthy thoroughbreds and 24 Arabians were used. Breath samples were collected using one-minute closed circulatory respiration through an aluminum bag filled with 10 liters of pure oxygen, which was mounted on the subjects by means of a face mask. Breath samples obtained, were analyzed by gas chromatography. A significant correlation in both hydrogen and methane levels was observed for samples collected at separate times. These findings confirmed the usefuln...
CT examination of the guttural pouch (auditory tube diverticulum) in Przewalski’s Horse (Equus przewalskii). The domestic horse (Equus caballus) have the large symmetrical guttural pouches (the auditory tube diverticulum) formed by saccate bulge of the auditory tube. In this study, CT examination was carried out in the head of Przewalski's horse (Equus przewalskii), the only true wild horse living at present. As results of the examination, Przewalski's horse possessed the large symmetrical guttural pouches divided into medial and lateral compartments by the stylohyoid bone. Moreover, the right and left guttural pouches meet each other at the median part to form a thin septum. As CT sections get close...
Structure of oxalate-substituted diferric mare lactoferrin at 2.7 A resolution. Lactoferrin binds two Fe(3+) and two CO(2-)(3) ions with high affinity. It can also bind other metal ions and anions. In order to determine the perturbations in the environments of the binding sites in the N and C lobes and elsewhere in the protein, the crystal structure of oxalate-substituted diferric mare lactoferrin has been determined at 2.7 A resolution. The final model has a crystallographic R factor of 21.3% for all data in the resolution range 17.0-2.7 A. The substitution of an oxalate anion does not perturb the overall structure of the protein, but produces several significant changes...
Effects of muscle glycogen depletion on some metabolic and physiological responses to submaximal treadmill exercise. The aim of this study was to investigate the effects of reduced muscle glycogen concentration on some physiological and metabolic responses during moderate intensity treadmill exercise in horses. Six Thoroughbred geldings were randomly allocated to 2 treatments (protocols A and B) or control in a 3 x 3 replicated Latin square design. In protocol A, horses performed low intensity exercise while horses in protocol B performed short bursts of high intensity exercise. Protocol A was designed to induce glycogen depletion mainly of slow twitch muscle fibers while protocol B aimed to deplete mainly f...
Age determination in mini-Shetland ponies and donkeys. The accuracy of ageing mini-Shetland ponies and donkeys was assessed by correlating the appearance of specific dental features with the known ages of 106 mini-Shetland ponies and 63 donkeys. The ages of the animals ranged between 2 days and 26 years. In both species the eruption of the deciduous and permanent incisors occurred later than in horses. On the other hand, the appearance of the dental stars on the permanent incisors of mini-Shetlands and donkeys was seen at a younger age than in horses. As in most horse breeds, the disappearance of the cups, the clinical crown lengths, the presence ...
Congenital atresia of the parotid duct in a horse. Congenital anomalies of the equine salivary glands and their ductal systems are rare. In man, parotid duct atresia is thought to be due to a congenital malformation of the first branchial arch. One horse with unilateral parotid salivary duct atresia is described. Imaging modalities available for accurate diagnosis, and treatment options, are reviewed.
Demographic characteristics of the equine population of northern Britain. The size, composition and distribution of the equine population of Scotland and the five northernmost counties in England were estimated through a series of mailed questionnaire surveys of sentinel veterinary practices and horse owners. An estimated 96,622 equine animals were kept by an estimated 26,114 owners. The mean (sd) age of the population was 11.0 (7.5) years (range one month to 37 years). Thoroughbred or thoroughbred-cross animals were the most numerous, constituting 30 per cent (95 per cent confidence interval 27 to 33 per cent) of the total population. The ratio of males:females was...
The molecular genetics of red and green color vision in mammals. To elucidate the molecular mechanisms of red-green color vision in mammals, we have cloned and sequenced the red and green opsin cDNAs of cat (Felis catus), horse (Equus caballus), gray squirrel (Sciurus carolinensis), white-tailed deer (Odocoileus virginianus), and guinea pig (Cavia porcellus). These opsins were expressed in COS1 cells and reconstituted with 11-cis-retinal. The purified visual pigments of the cat, horse, squirrel, deer, and guinea pig have lambdamax values at 553, 545, 532, 531, and 516 nm, respectively, which are precise to within +/-1 nm. We also regenerated the "true" red ...
Age-related changes to the molecular and cellular components of equine flexor tendons. Specific tendons show a high incidence of partial central core rupture which is preceded by degeneration. In the performance horse, the superficial digital flexor tendon (SDFT) is most often affected. We have described previously the molecular changes that are associated with degeneration in the central core region of the equine SDFT. The pathophysiological mechanism leading to change in synthetic activity of central zone cells in degenerated tendons is not known. In this study, we test the hypothesis that ageing results in matrix composition changes within the central zone of the SDFT. Extrac...
Cardiovascular demands of competition on low-goal (non-elite) polo ponies. Knowledge of the competitive demands of different sports or activities is important for designing appropriate training programmes to ensure that animals reach a sufficient level of fitness to reduce the risk of overexertion and injury or illness and to achieve the best possible performance in relation to an individual's genetic potential. Whilst the physiological demands of many equestrian sports have been described, to the best of our knowledge the cardiovascular demands of polo have not. The aims of the present study were therefore to record heart rate during and after competitive polo games...
Horse vision and an explanation for the visual behaviour originally explained by the ‘ramp retina’. Here we provide confirmation that the 'ramp retina' of the horse, once thought to result in head rotating visual behaviour, does not exist. We found a 9% variation in axial length of the eye between the streak region and the dorsal periphery. However, the difference was in the opposite direction to that proposed for the 'ramp retina'. Furthermore, acuity in the narrow, intense visual streak in the inferior retina is 16.5 cycles per degree compared with 2.7 cycles per degree in the periphery. Therefore, it is improbable that the horse rotates its head to focus onto the peripheral retina. Rather...
Supporting forelimb lameness: clinical judgement vs. computerised symmetry measurement. The aim of this study was to compare supporting forelimb lameness determined by a motion analysis system with the subjective grading of a trained equine orthopaedic surgeon. Trotting on a treadmill, 29 individuals with a supporting forelimb lameness were measured with the SELSPOT II system and judged by the clinician. The vertical motion of the head was measured, analysed using Fourier transform, and the percentages of symmetry determined. The veterinarian evaluated the lameness and graded it according to a clinical routine. Veterinarian and system for motion analysis assigned the lameness to ...
Natural variation of equine infectious anemia virus Gag protein cytotoxic T lymphocyte epitopes. Two defined cytotoxic T lymphocyte (CTL) epitopes from equine infectious anemia virus (EIAV)-infected horses, equine leukocyte alloantigen (ELA)-A5.1-restricted epitope 18a, and ELA-A9-restricted epitope 28b-1 were evaluated for conservation among three wild-type EIAV strains. Epitope 18a variation occurred in all three wild-type EIAV strains, while epitope 28b-1 varied in one strain. Further, 12% amino acid changes occurred in the Gag proteins of a recently isolated wild-type strain, documenting a much greater Gag protein variation than previously reported. Evaluation of epitope 18a among two...
Three-dimensional ultrastructure of synoviocytes in the horse joint as revealed by the scanning electron microscope. The synovial membrane displays a superficial cellular lining composed of two types of synoviocytes: "absorptive" macrophages (type A cells) and "secretory" fibroblast-like cells (type B cells). The types are intermingled and extend a variety of processes, rendering the cellular architecture of the synovial membrane difficult to visualize. Previous electron microscopic and histochemical studies failed to demonstrate the entire shape of synoviocytes, except our immunohistochemical study for protein gene product 9.5 in the horse joint. The present SEM study is the first to demonstrate the three-d...
An in vitro biomechanical comparison of an interlocking nail system and dynamic compression plate fixation of ostectomized equine third metacarpal bones. To compare the mechanical properties of two stabilization methods for ostectomized equine third metacarpi (MC3): (1) an interlocking nail system and (2) two dynamic compression plates. Animal or Sample Population-Ten pairs of adult equine forelimbs intact from the midradius distally. Methods: Ten pairs of equine MC3 were divided into two test groups (five pairs each): caudocranial four-point bending and torsion. Interlocking nails (6 hole, 13-mm diameter, 230-mm length) were placed in one randomly selected bone from each pair. Two dynamic compression plates one dorsally (12 hole, 4.5-mm broad)...
