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Topic:Animal Studies
Animal studies involving horses encompass a range of research focused on understanding equine biology, behavior, and health. These studies often investigate various aspects of horse physiology, genetics, nutrition, and disease pathology. Researchers utilize animal studies to explore the effects of different treatments, management practices, and environmental factors on horse welfare and performance. The findings from such studies contribute to the development of improved care strategies and health interventions. This page gathers peer-reviewed research studies and scholarly articles that explore the methodologies, findings, and implications of animal studies conducted on horses, providing insights into their application in advancing equine science.
Metabolic and osmoregulatory function at low and high (3800 m) altitude. Altitude evokes physiological adjustments that include not only respiratory and cardiovascular properties, but also metabolic function, renal and endocrine responses. The purpose of the present study was designed to expand our understanding of the physiological process involved with acclimatisation to high altitude in equids. The study examined temporal effects on metabolic and osmoregulatory function in horses (n = 6) at rest and postexercise at 3800 m. Animals were studied at 225 m (Pb = 743 mmHg) and during a 10 day stay at altitude (Pb = 487 mmHg). Rest samples were taken 90 min postprandi...
Effect of walking velocity on forelimb kinematics and kinetics. A database of biomechanical variables obtained from normal horses walking at a range of velocities is needed for comparison with the variables obtained from lame horses in which velocity cannot be predetermined. The objective was to investigate velocity-dependent changes in selected kinematic variables, ground reaction forces (GRF) and net joint energies in the forelimb and to develop statistical equations to calculate expected values of these variables for horses walking at different velocities. Five sound horses walked at a range of velocities (0.82 to 1.91 m/s) over a force plate. Kinematic...
Effect of molassed sugar beet pulp on nutrient utilisation and metabolic parameters during exercise. The aim of this study was to investigate the effect of partly replacing oats with molassed sugar beet pulp in a traditional hay/oat diet on nutrient utilisation and metabolic parameters in exercising horses. In a change-over experiment, 4 Standardbred geldings were fed a hay and oat-based diet (Oat diet) and a hay and oat-based diet where oats was partially replaced with molassed sugar beet pulp (MSBP diet). Each experimental period was 21 days during which total collection of faeces and urine was made and an exercise test (ET) performed. The crude fat digestibility was lower on the MSBP diet ...
Effect of training on age-related changes in plasma insulin and glucose. The purpose of the study was to determine whether 12 weeks of exercise training would affect plasma glucose and plasma insulin concentrations in young and older Standardbred mares. Eighteen healthy, unfit mares representing 3 age groups were used: young (Y = 6.8 +/- 0.4 years; n = 6), middle-aged (MA = 15.2 +/- 0.4; n = 6), and old (O = 27.0 +/- 0.2; n = 6). Pre- and post-training incremental exercise tests (GXT) were performed to measure plasma glucose and insulin concentration from immediately after, until 120 min postexercise. Training consisted of exercise 3 days/week (weeks 1-8) and 4 day...
Quantitative analysis of the organization of the inner nuclear layer of the horse retina. Four cell types including the bipolar, amacrine, horizontal and Muller cells were investigated quantitatively in the inner nuclear layer of the retina in the horse. Cells were identified on the basis of the morphology and distribution of processes leaving from their somata, cytological features and positional features. The average percentages of the above 4 cell types were 44%, 24%, 1% and 29%, respectively. The average total cell densities in the inner nuclear layer in the visual streak, the nasal and temporal regions, the dorsal and ventral regions of the retina were also estimated. It is ex...
Lack of parthenogenesis by Amblyomma cajennense (Acari: Ixodidae). Some reproductive parameters of adult stages of Amblyomma cajennense ticks were studied. The capacity of virgin females to reproduce by parthenogenesis was evaluated, during an experimental infestation, in absence of males, on a horse (Equus cabalus). Ticks were spread either completely free or in limited sites on the body of the animal. The engorged virgin females showed longer feeding periods and lighter body weights than those that had been fertilized. Some of these unmated females produced smaller egg masses, which had no embryonary development. On the other hand, females that had been ins...
Fenbendazole pharmacokinetics, metabolism, and potentiation in horses. The present study was designed to describe the pharmacokinetics and fecal excretion of fenbendazole (FBZ) and fenbendazole sulphoxide (FBZSO) and their metabolites in horses, to investigate the effects which concurrent feeding has on the absorption and pharmacokinetics of FBZ, and to determine the effect of coadministration of the metabolic inhibitor piperonyl-butoxide on the in vivo pharmacokinetics and in vitro liver microsomal metabolism of sulfide and sulfoxide benzimidazoles. The effect of piperonyl-butoxide on the enantiomeric genesis of the sulfoxide moiety was also investigated. Follow...
Collateral cartilage ossification of the distal phalanx in the Brazilian Jumper horse. Collateral cartilage ossification of the distal phalanx in the Brazilian Jumper horse is a common finding. The objective of this study was to evaluate the prevalence and the degree of ossification of the collateral cartilages of the distal phalanx in Brazilian Jumper horses. In an analysis of 652 collateral cartilages from the front feet of 163 horses, 93% of these cartilages had collateral cartilage ossification (P < 0.005), and 7% of these cartilages did not have any type of ossification. In ossified cartilages, 86.4% had ossification beginning from the base, and 6.6% had a separate cente...
Cytogenetic localization of 136 genes in the horse: comparative mapping with the human genome. The aim of this study was to increase the number of type I markers on the horse cytogenetic map and to improve comparison with maps of other species, thus facilitating positional candidate cloning studies. BAC clones from two different sources were FISH mapped: homologous horse BAC clones selected from our newly extended BAC library using consensus primer sequences and heterologous goat BAC clones. We report the localization of 136 genes on the horse cytogenetic map, almost doubling the number of cytogenetically mapped genes with 48 localizations from horse BAC clones and 88 from goat BAC clon...
Longitudinal development of kinematics in shetland ponies and the influence of feeding and training regimes. Nowadays, ponies are used more and more for competitive equine sports, driving and racing. The locomotor performance of ponies, however, has been evaluated in only a few kinematic and kinetic studies. To compare the longitudinal development of locomotor characteristics in the pony to the same process in the horse, the kinematics of 23 Shetland ponies were recorded at the trot on a treadmill (3 m/s) at ages 4 and 30 months using a modified CODA-3 apparatus. Furthermore, the influence of specific feeding and training regimes on this development was evaluated. It appeared that stride and stance d...
Endothelin response during and after exercise in horses. The objective of the present study was to measure plasma endothelin-1 (ET-1) at rest and during exercise in the horse. Six healthy, Standardbred and Thoroughbred mares (5.3+/-0.8 years; 445.2+/-13.1 kg) which were unfit, but otherwise accustomed to running on the treadmill, were used in the study. Plasma ET-1 concentrations were measured using a commercially available radioimmunoassay kit. Horses performed three trials: a standing control (CON) trial where blood was collected from the jugular vein every minute for 5 min; a graded exercise test (GXT) where blood samples were collected at the en...
Effects of repeated biopsying on muscle tissue in horses. The collection of muscle samples in horses to estimate their performance potential, adaptations to training and diagnosis of exertional myopathies is of increasing interest. This study was designed to examine whether repeated biopsying of the gluteus medius muscle at 7 week intervals alters morphology and muscle fibre variables in the sampling area. The gluteus had been biopsied 3 times previously, each biopsy separated by a 7 week interval. Seven weeks after the last biopsy, this study was initiated. Percutaneous needle biopsies were taken from left and right muscles at 2 depths (2 and 6 cm) ...
Quantitative motor unit action potential analysis of skeletal muscles in the Warmblood horse. Motor unit action potential (MUP) analysis in human medicine is a valuable and important diagnostic technique enabling discrimination between myogenic and neurogenic problems. This study establishes normative data in subclavian, triceps and lateral vastus muscles for clinical application of MUP analysis in the Warmblood horse, and examines whether muscle differences are present. Electromyographic (EMG) needle examination and MUP analysis were performed of the triceps, lateral vastus and subclavian muscles in 7 awake, nonsedated, Warmblood horses age 4-10 years. The amplitude, duration, number ...
A description of the motion of the navicular bone during in vitro vertical loading of the equine forelimb. Motion of the navicular bone might play a role in the development of navicular disease in horses but is difficult to asses. In the present study, 3-dimensional motion of this bone was determined using roentgen stereophotogrammetric analysis. Tantalum pellets were inserted, in vitro, in the bones of 6 forelimbs of mature Shetland ponies and kinematics were measured during vertical loading up to 2 kN. The motions of the navicular bone and coffin joint were limited to flexion/extension, there were no substantial out-of-plane motions. There was only little flexion between the navicular bone and th...
Pharmacokinetics of imidocarb dipropionate in horses after intramuscular administration. The objective of this study was to determine the pharmacokinetic behaviour of imidocarb in horses following a single i.m. injection at the dose commonly administered to treat Babesia caballi infections or to prevent babesiosis. Eight horses were injected i.m. with a single dose of 2.4 mg imidocarb dipropionate/kg bwt and blood, faecal, urine and milk samples were collected. For imidocarb determination, a high-performance liquid chromatographic method (HPLC) was used after weak cation-exchange solid phase, or liquid-liquid, extraction procedures. Twelve hours after treatment, no detectable plas...
Linkage of the grey coat colour locus to microsatellites on horse chromosome 25. The progressive loss of colour in the hair of grey horses is controlled by a dominantly inherited allele at the Grey locus (GG). In this study, two paternal Quarter Horse (QH) families segregating for the GG allele were genotyped with a set of 101 microsatellite markers spanning the 31 autosomes and the X chromosome. This genome scan demonstrated linkage of Grey to COR018 (RF=0.02, LOD=12.04) on horse chromosome 25 (ECA25). Further chromosome-specific analysis of seven total QH families confirmed the linkage of Grey to a group of ECA25 markers and the map order of NVHEQ43-(0.24)-UCDEQ405-(0.09...
Assignment of the horse grey coat colour gene to ECA25 using whole genome scanning. The dominant grey coat colour gene of horses has been mapped using a whole genome scanning approach. Samples from a large half-sibling pedigree of Thoroughbred horses were utilized in order to map the grey coat colour locus, G. Multiplex groups of microsatellite markers were developed and used to efficiently screen the horse genome at a resolution of approximately 22 cM, based on an estimated map length for the horse genome of 2720 cM. The grey gene was assigned to chromosome 25 (ECA25), one of the smaller acrocentric horse chromosomes. Based on the current state of knowledge of conserved synt...
Neutralizing antibodies against vesicular stomatitis viruses (serotypes New Jersey and Indiana) in horses in Costa Rica. Serum samples were collected from domestic horses in 4 different regions of Costa Rica to detect antibodies against vesicular stomatitis viruses, serotypes New Jersey (VSV-NJ) and Indiana (VSV-IN). A total of 214 samples were tested by the virus neutralization test. The sampling regions were identified as low North Pacific dry area (1), low Middle Atlantic humid area (2), low South Pacific humid area (3), and the highlands (4). In region 1, 97.1% of horses were positive for VSV-NJ and 16.5% were positive for VSV-IN. The mean antibody titer and its standard deviation after logarithmic transform...
Correlation between the osmotic second virial coefficient and solubility for equine serum albumin and ovalbumin. The Haas - Drenth - Wilson (HDW) (Haas et al., 1999) theoretical model was used to correlate osmotic second virial coefficient (B) values with solubility (S) values for equine serum albumin (ESA) and ovalbumin for corresponding solution conditions. The best fit from the theoretical model was compared to experimental S versus B data. B values were experimentally measured using static light scattering. Solubilities of ESA were estimated using a sitting drop method. When the experimental data for S versus B were plotted, an excellent fit for ESA was obtained according to the HDW model. The result...
Equine fetal sex determination using a single ultrasonic examination under farm conditions. The aims of this study were to evaluate the reliability, under general farm conditions, of the use of a single transrectal sonogram in pregnant mares to determine fetal sex by locating the genital tubercle, and the feasibility of extending the period of gestation in which this examination can be carried out. This research was done during routine reproductive examinations on three different stud farms. Forty mares between the 54th and the 89th day of gestation were examined once; gestation was calculated by identifying the last day of mating as Day 0. In order to verify the precision of the det...
Two-dimensional and M-mode echocardiographic measurements of cardiac dimensions in healthy standardbred trotters. The aim of the study was to establish normal echocardiographic values of healthy Standardbred trotters not published previously. Twenty-three clinically normal horses weighing between 350 and 490 kg were examined in the same manner: first a thorough physical and then detailed echocardiographic examination were performed. Standardised two-dimensional (2D) and guided M-mode echocardiographic imaging techniques were used to measure interventricular septal thickness (IVS), left ventricular internal diameter (LVID), left ventricular wall thickness (LVW), left atrial internal diameter (LAID) in end-...
Selection of recently isolated colicinogenic Escherichia coli strains inhibitory to Escherichia coli O157:H7. Escherichia coli strains were screened for their ability to inhibit E. coli O157:H7. An initial evaluation of 18 strains carrying previously characterized colicins determined that only colicin E7 inhibited all of the E. coli O157:H7 strains tested. A total of 540 strains that had recently been isolated from humans and nine different animal species (cats, cattle, chickens, deer, dogs, ducks, horses, pigs, and sheep) were tested by a flip-plating technique. Approximately 38% of these strains were found to inhibit noncolicinogenic E. coli K12 strains. The percentage of potentially colicinogenic E...
Measurement of leptin and insulin-like growth factor-I in seminal plasma from different species. The multi-functional proteins, insulin-like growth factor-I (IGF-I) and leptin were present in seminal plasma from different species. Concentrations of IGF-I in equine and porcine semen were 20 and 17.5 ng/ml, respectively. Seminal plasma concentrations of leptin were 1 ng/ml in human and 11 ng/ml in porcine samples.
[Horse breeding: genetic tests for the coat colors chestnut, bay and black. Results from a preliminary study in the Swiss Freiberger horse breed]. Coat color played an important role during domestication and formation of breeds. Livestock breeders often had special preferences for particular color phenotypes because they believed them to be associated with performance or fitness traits. Socio-cultural reasons might have had an influence on color selection as well. Recently genetic tests on DNA level got available to genotype in any individual horse for basic horse coat colors (chestnut, bay, black). In particular, hidden carriers of the recessive chestnut and black allele are recognizable with these tests. A sample of 162 Franches-Montag...
[Microsatellite analysis in a population of Baudet du Poitou donkeys]. A population of Baudet du Poitou donkeys was genetically characterized using microsatellites. The results were used to verify the pedigrees and to estimate the genetic variability. It could be confirmed that a equine parentage test kit works well for donkeys and that by using 13 microsatellites more than 99% of wrong pedigree informations would be detected. The genetic variability was comparable to a representative group of Baudet du Poitou donkeys in France.
Spatial distribution of fiber types within skeletal muscle fascicles from Standardbred horses. Skeletal muscle fascicles from superficial and deep portions of semitendinosus (ST) and gluteus medius (GM) muscles from Standardbred trotters were analyzed with regard to muscle fiber type proportion (types I, IIA, and IIB) and spatial distribution. Muscle fibers within a fascicle were divided into four layers (L(1-4)) from the fascicle periphery toward the center. The observed proportions of fiber types among layers were found to be statistically significantly different from a random distribution of fiber types. Type IIB fibers predominated in the peripheral layer, type I fibers prevailed in...
The potential reservoir role of donkeys and horses in zoonotic fascioliasis in Gharbia Governorate, Egypt. No doubt, fascioliasis tops all the zoonotic helminthes worldwide. In Egypt, human fascioliasis is increasing. The incidence and prevalence of fascioliasis in the Egyptian farm animals are well documented. However, none in Egypt has focused on the potential role of other domestic farm animals. A preliminary coprologic examination of donkeys and horses was done in eight centers of Gharbia governorate. The overall rate of infection in donkeys was 3.03%, in horses was 1.5%, and in mules 0.0%. Horses 2/74 (2.70%) and 1/26 (3.86%) were infected in Zefta and El Mahala El Kobra centers respectively. ...
Protamine P1 sequences in equids: comparison with even-toed animals. Protamine P1 amino acid sequences were determined from semen samples of the Przewalski horse, donkey, Somali wild ass, Grevy's zebra, and Grant's zebra (odd-toed perissodactyls), and compared with those of the domestic horse. Although the rate of amino acid variation of protamine P1 is known to be among the most rapidly diverging polypeptides, the equid sequences revealed only little variation. The sequence from the Przewalski horse was identical with that from the domestic horse. The other sequences differed from the corresponding sequences of the domestic and Przewalski horses in two positio...
