Equine biomechanics involves the study of the mechanical principles that govern the movement and structure of horses. This field examines the anatomical and physiological aspects that contribute to locomotion, including gait patterns, joint function, and muscle dynamics. Researchers utilize advanced technologies such as motion capture and force plate analysis to assess the efficiency and performance of equine movement. Understanding biomechanics aids in optimizing training regimens, improving performance, and preventing injuries. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanics of equine movement, its applications in sports and rehabilitation, and its impact on overall equine health.
Greening L, Harkin E, Kyriazopoulou P, Heppelthwaite Z, Aragona F, Browne JA, Hemmings A, Williams JM, Murphy BA.Modern horse husbandry involves significant time spent indoors, often in suboptimal lighting conditions and with frequent night-time disturbances by humans for management purposes. The aim of this study was to investigate the influence of a customised light-emitting diode (LED) lighting system and a standard fluorescent lighting fixture on equine sleep behaviours, circadian rhythmicity and spontaneous blink rates in horses. Ten riding school horses experienced two stable lighting conditions for four weeks each in a cross-over study running from January to March, 2023. The treatment lighting co...
Avila F, Esdaile E, Bellone RR. Standardbreds, a breed of horses used in harness racing at either the trot or the pace, established a closed studbook in 1973. Concerns about genetic diversity within the breed led the United States Trotting Association (USTA) to establish a limit of mares bred per stallion (i.e., a studbook cap) in 2009. Here, we aimed to evaluate the impact of the breeding restrictions on genetic diversity between and among subpopulations. : Sixteen short tandem repeats (STRs) were analyzed across a dataset of 176,424 Standardbreds foaled in the United States between 1998 and 2021. We examined allelic richn...
Mellish M, Burns J, Elce Y, Stull JW.Donkeys (Equus asinus) in East Africa are recognised as working with poorly designed harnesses and carts. The donkey cart used in regions of Africa, specifically Meru County, Kenya, appears to place the cart's weight solely on the donkey's mid-cervical region. The ventral area of the neck is vulnerable to external pressure on the trachea, which is superficially located. Objective: To compare the presence and severity of endoscopic abnormalities in the upper airway and trachea of Meru County working cart donkeys compared to pack donkeys. To determine associations between endoscopic and physical...
Santos L, Werfel K, Ferlini-Agne G.Accurate measurement of haemoglobin concentration is crucial for monitoring the oxygen-carrying capacity in anaesthetised horses. This prospective study aimed to determine the agreement in haemoglobin concentration in anaesthetised horses using the SpHb pulse co-oximeter, an Epoc® blood gas analyser, and values derived from packed cell volume (PCV), which served as the reference method in this study. The study included 34 horses undergoing elective surgeries. Blood samples were collected from each horse and divided for analysis using the microhaematocrit method to estimate haemoglobin concent...
Furukawa R, Tozaki T, Kawate K, Kikuchi M, Ishige T, Takahashi Y, Fukui E, Kakoi H.Gene doping, which entails the administration of transgenes, poses a serious threat to the integrity of equine sports and also raises both ethical and regulatory concerns. Current methods used for the detection of such doping often necessitate the extraction of DNA from plasma, which can be time-consuming and labour-intensive. To overcome this limitation, we developed a direct chamber digital PCR (cdPCR) method that enables transgene detection in equine plasma without the need for DNA purification. Using the equine erythropoietin (EPO) transgene as a model, we validated the assay by analysing ...
Vicenti C, Cercone M, Nieman G, Habashi NM, Andrews P, Satalin J, Velarde P, Mitchell KJ, Louie EW, Albano V, Ali H, King A, Staffieri F, Gleed R....To compare early versus late time-controlled adaptive ventilation (TCAV) for setting airway pressure release ventilation (APRV) on arterial oxygenation in dorsally recumbent anesthetized horses. Methods: A crossover, nonrandomized, experimental study. Methods: Six healthy adult horses. Methods: Each horse underwent two anesthetics: 1) volume-controlled ventilation (VCV) began for 30 minutes before switching to APRV using the TCAV method (late TCAV, TCAV); and 2) ventilation began immediately with TCAV (early TCAV, TCAV). The study lasted 180 minutes, with arterial blood gases and respiratory m...
Beggan CP, Panizzi L, Oliver LJ.To measure microsphere recovery following needle-through-and-through lavage (NTAT) of the metacarpo-/metatarsophalangeal joint (fetlock) and digital flexor tendon sheath (DFTS) compared to endoscopic lavage (EL). Methods: Ex vivo experimental study. Methods: Adult equine cadavers immediately following euthanasia (n = 10). Methods: Colored 15 μm microspheres (2 million) were injected into fetlock joints and DFTS. Synovial structures were assigned to NTAT or EL groups. Each lavage was performed using 5 L of 0.9% NaCl, sequentially collecting egress fluid for microsphere quantification. Re...
Tually P, Currie G.The horse racing industry, like any sport, must contend with the effects of injuries on an athlete's performance and longevity. Catastrophic fractures linked to preexisting bone fatigue can be prevented with the use of imaging technology, such as the nuclear medicine bone scan. The accessibility and affordability of imaging for racehorses remain obstacles. The conventional role of bone scintigraphy has evolved with the advent of advanced techniques, including MRI, CT, and PET. Concurrently, SPECT has expanded the role of scintigraphy in the racehorse. This article explores the conventional and...
Reemtsma FP, Giers J, Horstmann S, Stoeckle SD, Gehlen H.Plasma amino acid (PAA) concentration in horses vary according to the exercise type. This study evaluated the changes in PAA levels and the associated metabolites, urea and ammonia, following short-duration, high-intensity cross-country exercise in eventing horses. Twenty eventing horses participated in 55 rides at 14 international competitions (2* to 4* levels) across five venues in Germany and Poland. Blood samples were collected at four timepoints: before exercise (TP0), at 10 min (TP1), and at 30 min (TP2) post-exercise, as well as in the morning on the day after the competition (TP3). A t...
Collins E, Barr E, Zhang C, Steadman M, Gilger B, Henriksen ML.To describe the most efficient topical horizontally centrifuged platelet-rich fibrin (H-PRF) treatment protocol for equine ulcerative keratitis (EUK) that is easy to use, and to report the preliminary concentration of growth factors and cytokines in equine H-PRF. Unassigned: 5 client-owned horses diagnosed with EUK were enrolled over an 11-month period. Unassigned: 3 horses were geldings, and 2 were mares. The mean (± SD) age was 5.95 ± 5.01 years. The owners' main goal was to avoid surgery for EUK. Unassigned: H-PRF was used in 3 different protocols: solid H-PRF, sutured to the EUK area (n ...
Walz KR, McCormick ME, Fedorka CE.Breed bias exists within many of the top disciplines of equestrian sport. Therefore, the objective of this study was to evaluate the influence of breed on performance at the CCI5*-L level of eventing. To do so, the results of all CCI5*-L events from 2014 to 2024 were assessed. Initially, Thoroughbreds were compared to all non-Thoroughbreds, and this was followed by assessing the ten primary breeds. Data included penalties accrued in dressage, cross country, show jumping, and overall. Additionally, the likelihood of completing each phase was assessed. It was found that Thoroughbreds accrued mor...
Meistro F, Ralletti MV, Rinnovati R, Spadari A.Subtle locomotor asymmetries are common in horses and may go unnoticed during routine pre-race clinical inspections, particularly when based solely on subjective evaluation. This study aimed to describe vertical head and pelvic movement asymmetries in racehorses that passed official pre-race inspections at a traditional racing event. Twenty-four horses were analysed using a markerless AI-based gait analysis system while trotting in-hand and during lungeing in both directions. Asymmetry parameters (HDmin, HDmax, PDmin, and PDmax) were extracted from video recordings, with values ≥0.5 consider...
Ablondi M, Eriksson S, Mikko S.Fragile foal syndrome (FFS) is a disease caused by a recessive lethal missense mutation in the PLOD1 gene located on ECA2. Despite its harmful effect, a relatively high frequency of FFS carriers was observed in Warmblood breeds spanning from 7.4% in a random sample of Swedish Warmblood breed to 17% in the Hanoverian and Danish Warmblood, indicating potential heterozygous advantage. Balancing selection can be further studied based on haplotype blocks and via detection of heterozygosity-rich region (ROHet) around the target of selection. In this study we evaluated the presence of haplotype block...
Zupan Šemrov M, Přibylová L, Gobbo E.Equine locomotion emerges from a dynamic interplay between morphology, biomechanics, and functional demands. This study examines the relationship between morphological measurements and gait kinematics in Lipizzan horses, a breed renowned for its diverse work tasks and standardized environmental conditions. These horses offer a unique opportunity to explore task-specific adaptations in biomechanics, with significant implications for breeding strategies and welfare practices. Unassigned: The study involved 71 healthy Lipizzan horses that were housed at the Lipica stud farm and performed various ...
Herkenhoff ME.MicroRNAs (miRNAs) are molecules that regulate gene expression by targeting the 3' untranslated region (UTR) of mRNAs. They are essential in numerous biological processes like growth, metabolism, and muscle development. miRNA research has become crucial in livestock breeding, offering solutions for improving animal health and productivity. This review focuses on miRNAs' roles in equine performance, reproduction, and disease, highlighting key findings and future applications in these areas. It discusses the use of circulating miRNAs (ci-miRNA) as biomarkers for athletic performance, particularl...
Kwaß LM, Khiaosa-Ard R, Zebeli Q, Sulyok M, Milojevic V, Metzler-Zebeli BU.The occurrence of biotoxins and chemical residues in marketed horse feeds has direct influences on horse health but has not been studied yet. Objective: The study investigated the exposure and health implications of contaminants in various horse feedstuffs available on the European market. Methods: A total of 108 feed samples representing diverse product categories such as hay, processed roughage products, grains, and various supplementary feeds were collected from different European countries and analyzed for contaminants, including mycotoxins, phytoestrogens, pesticides, and veterinary drug ...
Kroschel L, Pilger F, Aurich J, Nagel C, Aurich C.Horses in training are often stabled individually, but this is increasingly questioned. We have investigated the effects of different stabling systems in Warmblood stallions during a 12-week pretraining programme. Stallions were 24 months old and housed either in a group stable (Group 24, n = 9) or in individual boxes (Box 24, n = 10), or they were 30 months of age and housed in individual boxes (Box 30, n = 10). Cortisol, heart rate, heart rate variability (HRV), body development, injuries and selected behaviour patterns were analysed (1) at transfer from pasture to stable and (2) the...
Koch DW.Our understanding of tendon homeostasis and repair following injury has made great strides through basic science, clinical veterinary medicine, and preclinical translational research. We have now gleaned a greater understanding of the cellular and matrix dynamics that are being orchestrated within the tendon, which provide therapeutic opportunities. This article will focus on how utilizing the horse and equine tissues have advanced our understanding of tendinopathy and the cellular and matrix dynamics at play while also identifying continued gaps in our knowledge where the horse as a veterinar...
Pluim M, Reynolds A, McClure S.High-power laser therapy and extracorporeal shock wave therapy (ESWT) can be safely used to treat tendon and ligament injuries in horses, and the potential beneficial effects have been described. The power of low level lasers is not sufficient for treatment of tendon and ligament injuries in horses. ESWT is used more often to treat tendon and ligament injuries than it is for any other type of condition in horses, but there is limited supporting scientific evidence. Further research should focus on establishing dosage and treatment protocols for both laser therapy and ESWT in horses with clinic...
Connard SS, Schnabel LV.This review explores the use of biologics in the treatment of tendon and ligament injuries in horses, focusing on current and emerging therapies aimed at enhancing tissue repair and regeneration. It discusses the role of scaffold-based therapies, growth factors, blood-derived and tissue-derived biologics, and gene therapy as biologic regenerative therapies for improving healing outcomes. The review evaluates the mechanisms, efficacy, and challenges of biologics in clinical applications, highlighting recent advances and clinical studies. It provides an overview of current trends and future dire...
Zamboulis DE, Thorpe CT.The high stresses and strains experienced by the superficial digital flexor tendon (SDFT) make it prone to age-related injury. The SDFT exhibits cellular and structural specializations, localized to the interfascicular matrix (IFM), enabling it to resist its extreme mechanical environment. With aging, these specializations are lost, impacting the ability of the tendon to withstand repeated loading. Within the IFM, there is loss of mechanical properties and organization accompanying cell senescence and a decreased resolution of inflammation. Developing therapeutics to reverse these changes may,...
Tarillion M, Hertzsch R, Richter A.Since 28.01.2022, veterinary medicinal products must be used in accordance with the conditions of authorization (Regulation (EU) 2019/6, Article 106). This entails further restrictions on therapeutic freedom, e. g., with regard to dose deviations. To date, there is no data available in equine medicine on the scope of off-label use as any use deviating from the expert information for antibiotics, on the basis of which the feasibility of implementing the new regulations in Germany can be assessed.To collect data on the off-label use of antibiotics, a Germany-wide anonymous online survey was th...
Maguire M, Brusie R.To determine the outcome of skeletally mature performance horses with subchondral bone cysts and fissures in the proximal aspect of the first phalanx treated by lag screw compression. Unassigned: Case records of horses that underwent lag screw compression to treat subchondral bone lesions in the proximal aspect of the first phalanx were reviewed. Performance horses > 5 years old with lameness referrable to the fetlock region; radiographic or other advanced imaging evidence of subchondral bone lesions, with no other concurrent cause for lameness; and at least 6 months of follow-up data were inc...
de Preux M, Precht C, Becker R, Stieglitz L, Easley J, Koch C.Trigeminal-mediated headshaking is a neuropathic disorder in horses, characterized by signs of regional pain similar to trigeminal neuralgia in humans. The injection of glycerol into the trigeminal cistern to ablate pain-conducting nerve fibers within the trigeminal ganglion -known as glycerol rhizotomy- is a well-established treatment in human medicine. This study compares two approaches to the equine trigeminal cistern using a navigation system for guiding needle placement, a previously described ventral and a newly developed transmandibular lateral approach. The surgical accuracy and risk o...
Medica AJ, Swegen A, Seifi-Jamadi A, McIntosh K, Gibb Z.Oxidative stress plays a critical role in regulating sperm function, yet species-specific antioxidant mechanisms remain poorly understood. This study compared hydrogen peroxide (H2O2) tolerance in horse and human sperm and investigated the roles of catalase and glutathione peroxidase (GPx) in horses. A H2O2 dose-response assay (0-2000 µM) showed that horse sperm were significantly more resistant to oxidative damage, with an IC50 for progressive motility over 14-fold higher than that of human sperm (391.6 µM vs. 27.3 µM). Horse sperm also accumulated more intracellular H2O2 without loss of m...
Bonow S, Hernlund E, Eriksson S, Strandberg E, Gelinder Viklund Å.Sweden has a strong tradition of insuring horses for veterinary costs, and orthopedic diagnoses are the most common for insurance claims. The aim of this study was to investigate differences in prevalence and risk of orthopedic diagnoses for Swedish warmblood (SWB) horses classified as jumping (J) or dressage (D) horses. Also, other factors that may influence orthopedic health were investigated, i.e., sex, birth cohort, and participation in young horse tests and competition. The data consisted of 15,619 insured SWB horses born between 2010 and 2020. Horses were classified as J or D horses acco...
Chen J, Yablon A, Metaxas C, Guedin M, Hu J, Conover K, Simpson M, Ralston SL, Krishnamurthy K, Pelczer I.: There are a few very specific inflammation biomarkers in blood, namely lipoprotein NMe signals of protein clusters (GlycA and GlycB) and a composite resonance of phospholipids (SPC). The relative integrals of these resonances provide clear indication of the unique metabolic changes associated with disease, specifically inflammatory conditions, often related to serious diseases such as cancer or COVID-19 infection. Relatively complicated, yet very efficient experimental methods have been introduced recently (DIRE, JEDI) to suppress the rest of the spectrum, thus allowing measurement of these ...
Liu Y, Liu Y, Bai D, Dugarjaviin M, Zhang X.Skeletal muscle satellite cells are muscle stem cells that play an important role in the growth, development, and repair of skeletal muscle as well as in the locomotor performance of the animal body. Lysine is the first limiting amino acid and is involved in multiple metabolic pathways in the organism to maintain overall physiological requirements. In this study, Mongolian horse satellite cells were cultured using lysine culture solution at different concentrations, and the proliferative capacity of satellite cells was detected by the cck-8 assay, and the optimal culture concentration was sele...
Fakhar-I-Adil M, Angel-Velez D, Araftpoor E, Amin QA, Hedia M, Bühler M, Gevaert K, Menten B, Van Soom A, Chuva de Sousa Lopes SM, Stoop D, De Roo C....In vitro maturation (IVM) of oocytes retrieved from ovum pick-up (OPU) or ovarian tissue (OT) is a standard approach for patients with specific conditions where prior hormonal stimulation is contraindicated. However, the developmental competence of oocytes matured in vitro is still inferior to that of oocytes matured in vivo. Capacitation IVM (CAPA-IVM) includes an extra step of pre-maturation culture (PMC) with c-type natriuretic peptide (CNP) as a meiotic arrestor to better synchronize cytoplasmic and nuclear maturity in oocytes by allowing the cytoplasm additional time to acquire essential ...
Lopes MS, Mendonça D, Cymbron T, Valera M, da Costa-Ferreira J, Machado Ada C.The analysis of mitochondrial D-loop sequences (408 bp) from 145 Lusitano founder mares yielded a total of 27 different haplotypes. The distribution of these mtDNA sequences was quite unequal, with the three most frequent ones representing 56.5% of all the Lusitano founder mares and 14 haplotypes (51.9%) being rare variants found only once in the sampling. Four main haplotype clusters were present in the Lusitano breed. The comparison of these sequences with other equine haplotypes shows that they fall in groups shared with other horse breeds. These data support the hypothesis of multiple dome...
Rochais C, Sébilleau M, Menoret M, Oger M, Henry S, Hausberger M, Cousillas H.Lateralization of brain functions has been suggested to provide individuals with advantages, such as an increase of neural efficiency. The right hemisphere is likely to be specialized for processing attention for details and the left hemisphere for categorization of stimuli. Thus attentional processes actually may underlie lateralization. In the present study, we hypothesized that the attentional state of horses could be reflected in the lateralization of brain responses. We used i) a recently developed attention test to measure horses' visual attentional responses towards a standardized stimu...
Connysson M, Essén-Gustavsson B, Lindberg JE, Jansson A.A higher forage allowance to athletic horses might be an alternative to increase health and the gut fluid reservoir. However, more forage might increase bodyweight (bwt) and could therefore be a limitation during competition. Objective: To investigate the effect of a forage-only diet (FD) compared to a 50:50 (dry matter basis) forage:oats diet (OD) on bwt, plasma protein concentration and some metabolic plasma parameters during 12 h of feed deprivation. Methods: Twelve adult Standardbred horses in training were used. The 2 diets were fed in 2 experimental periods of 3 weeks each in a crossover...
Huang W, Yaraghi NA, Yang W, Velazquez-Olivera A, Li Z, Ritchie RO, Kisailus D, Stover SM, McKittrick J.The equine hoof has been considered as an efficient energy absorption layer that protects the skeletal elements from impact when galloping. In the present study, the hierarchical structure of a fresh equine hoof wall and the energy absorption mechanisms are investigated. Tubules are found embedded in the intertubular matrix forming the hoof wall at the microscale. Both tubules and intertubular areas consist of keratin cells, in which keratin crystalline intermediate filaments (IFs) and amorphous keratin fill the cytoskeletons. Cell sizes, shapes and IF fractions are different between tubular a...
de Cocq P, Duncker AM, Clayton HM, Bobbert MF, Muller M, van Leeuwen JL.In equestrian sports, it is generally assumed that rising and sitting trot load the horse's back differently. The objective of this study was to quantify the load on the horse's back in these riding techniques. Kinematic data of 13 riders were collected in rising and sitting trot. The time-history of the position of the rider's centre of mass (CoM) was calculated, and differentiated twice to obtain the acceleration of the CoM. The reaction force between the rider and the horse's back was calculated from the acceleration. Forces were divided by the body weight of the rider to obtain dimensionle...
Biknevicius AR, Mullineaux DR, Clayton HM.To evaluate the locomotor mechanics of the tölt in Icelandic horses. Methods: 10 adult Icelandic horses with no history of lameness. Methods: Force platform data were captured for 27 trials for horses ridden at a tölt in a lateral sequence single-foot gait at a steady speed from 0.89 to 5.98 m/s. Simultaneous kinematic data were obtained by tracking retroflective markers overlying the right fore- and hind limbs. These kinetic and kinematic data were combined to evaluate 3 mechanical approaches, duty factor, Froude number, and center of mass (COM) mechanics, and to evaluate the capacity to re...
van Heel MC, Barneveld A, van Weeren PR, Back W.Studies on hoof balance have, so far, only assessed the effects of strong and relatively unrealistic interventions due to technical limitations of measuring equipment. For the assessment of more subtle interventions, other techniques are necessary. Objective: To test a sensitive pressure measurement system during locomotion and to set a standard for further studies by using the system to evaluate the effects of trimming. Methods: Eighteen horses were measured before and after trimming with an interval of 4 weeks. Trimming was standardised to a straight hoof-pastern axis. The horses trotted ove...
Han H, McGivney BA, Farries G, Katz LM, MacHugh DE, Randhawa IAS, Hill EW.Thoroughbred horse racing is a global sport with major hubs in Europe, North America, Australasia and Japan. Regional preferences for certain traits have resulted in phenotypic variation that may result from adaptation to the local racing ecosystem. Here, we test the hypothesis that genes selected for regional phenotypic variation may be identified by analysis of selection signatures in pan-genomic SNP genotype data. Comparing Australian to non-Australian Thoroughbred horses (n = 99), the most highly differentiated loci in a composite selection signals (CSS) analysis were on ECA6 (34.75-34.85 ...
Lyons ET, Tolliver SC, Kuzmina TA, Collins SS.Critical tests were performed in 2009 and 2010 in four 2-year-old horses naturally infected with internal parasites. The horses were from a herd (Farm MC) where reduced activity of ivermectin and moxidectin on small strongyles was demonstrated previously from EPG (eggs/gram of feces) data in field tests. Also, in critical tests in horses from the same herd, ivermectin was less effective on immature small strongyles in the lumen of the large intestine than when the drug was first marketed. The main interest in the present critical tests was to determine the efficacy of moxidectin (400 μg/kg) o...
Eisersiö M, Roepstorff L, Weishaupt MA, Egenvall A.The aim of this study was to investigate the behavioural response of horses to rein contact and the movement of the riders' hands through analysis of data from horses ridden at two different head and neck positions. It was hypothesised that the riders' hand movements and rein tension would generate behavioural responses from horses and that these responses would be more marked when horses were ridden 'on the bit' than when unrestrained. Data were collected from seven dressage horse/rider combinations at sitting trot on a high speed treadmill. Kinematics were recorded using a 12-camera, infrare...
Clayton HM.The objective was to determine whether collected trot, passage and piaffe could be distinguished as separate gaits on the basis of temporal variables. Sagittal plane, 60 Hz videotapes of 10 finalists in the dressage competitions at the 1992 Olympic Games were analysed to measure the temporal variables in absolute terms and as percentages of stride duration. Classification was based on analysis of variance, a graphical method and discriminant analysis. Stride duration was sufficient to distinguish collected trot from passage and piaffe in all horses. The analysis of variance showed that the mea...
Gunther MR, Sturgeon BE, Mason RP.The reaction between metmyoglobin (metMb) and hydrogen peroxide has been known since the 1950s to produce globin-centered free radicals. The direct electron spin resonance spectrum of a solution of horse metMb and hydrogen peroxide at room temperature consists of a multilined signal that decays in minutes at room temperature. Comparison of the direct ESR spectra obtained from the system under N(2)- and O(2)-saturated conditions demonstrates the presence of a peroxyl radical, identified by its g-value of 2.014. Computer simulations of the spectra recorded 3 s after the mixture of metMb and H(2)...
Elashry MI, Baulig N, Wagner AS, Klymiuk MC, Kruppke B, Hanke T, Wenisch S, Arnhold S.Combination of mesenchymal stem cells (MSCs) and biomaterials is a rapidly growing approach in regenerative medicine particularly for chronic degenerative disorders including osteoarthritis and osteoporosis. The present study examined the effect of biomaterial scaffolds on equine adipose-derived MSC morphology, viability, adherence, migration, and osteogenic differentiation. MSCs were cultivated in conjunction with collagen CultiSpher-S Microcarrier (MC), nanocomposite xerogels B30 and combined B30 with strontium (B30Str) biomaterials in osteogenic differentiation medium either under static or...
Timney B, Keil K.Although horses have laterally-placed eyes, there is substantial binocular overlap, allowing for the possibility that these animals have stereopsis. In the first experiment of the present study we measured local stereopsis by obtaining monocular and binocular depth thresholds for renal depth stimuli. On all measures, the horses' binocular performance was superior to their monocular. When depth thresholds were obtained, binocular thresholds were several times superior to those obtained monocularly, suggesting that the animals could use stereoscopic information when it was available. The binocul...
Brandariz-Fontes C, Leonard JA, Vega-Pla JL, Backström N, Lindgren G, Lippold S, Rico C.Several studies based on a variety of genetic markers have attempted to establish the origins of horse domestication. Thus far a discrepancy between the results of mitochondrial DNA analysis, which show high levels of diversity, and results from the Y-chromosome, with almost no genetic variability, has been identified. Most previous work on the horse Y-chromosome has focused on widespread, popular breeds or local Asian breeds. It is possible that these breeds represent a reduced set of the genetic variation present in the species. Additional genetic variation may be present in local breeds and...
Terzi A, Gallo N, Bettini S, Sibillano T, Altamura D, Campa L, Natali ML, Salvatore L, Madaghiele M, De Caro L, Valli L, Sannino A, Giannini C.The aim of this work is to evaluate the effects of different extraction and material processing protocols on the collagen structure and hierarchical organization of equine tendons. Wide and Small Angle X-ray Scattering investigations on raw powders and thin films revealed that not only the extraction and purification treatments, but also the processing conditions may affect the extent of the protein crystalline domain and induce a nanoscale "shield effect." This is due to the supramolecular fiber organization, which protects the atomic scale structure from the modifications that occur during f...
Flood PF, Betteridge KJ, Diocee MS.The 23 embryos were obtained by flushing the reproductive tract. Though the general cytology was observed, most attention was given to the formation of the embryonic capsule. It first appeared as a thin uniform layer on the inner surface of the zona pellucida of embryos recovered from the uterus on Day 6. By Day 8 the capsule was about 1 micron thick and the zona pellucida had been shed. In fixed embryos of 11 days and over the capsule was 3 microns thick and had a finely stippled but otherwise homogeneous appearance.
Bjørnstad G, Nilsen NØ, Røed KH.Human populations of Central Asian origin have contributed genetic material to northern European populations. It is likely that migrating humans carried livestock to ensure food and ease transportation. Thus, eastern genes could also have dispersed to northern European livestock populations. Using microsatellite data, we here report that the essentially different genetic distances DA and (deltamu)2 and their corresponding phylogenetic trees show close associations between the Mongolian native horse and northern European horse breeds. The genetic distances between the northern European breeds a...
Hanot P, Herrel A, Guintard C, Cornette R.The relationships between the different component parts of organisms, such as the sharing of common development or function, produce a coordinated variation between the different traits. This morphological integration contributes to drive or constrain morphological variation and thus impacts phenotypic diversification. Artificial selection is known to contribute significantly to phenotypic diversification of domestic species. However, little attention has been paid to its potential impact on integration patterns. This study explores the patterns of integration in the limb bones of different ho...
Roth LS, Balkenius A, Kelber A.Most mammals have dichromatic colour vision based on two different types of cones: a short-wavelength-sensitive cone and a long-wavelength-sensitive cone. Comparing the signal from two cone types gives rise to a one-dimensional chromatic space when brightness is excluded. The so-called ;neutral point' refers to the wavelength that the animal cannot distinguish from achromatic light such as white or grey because it stimulates both cone types equally. The question is: how do dichromats perceive their chromatic space? Do they experience a continuous scale of colours or does the neutral point divi...
Wickler SJ, Hoyt DF, Clayton HM, Mullineaux DR, Cogger EA, Sandoval E, McGuire R, Lopez C.It is well known that adding a load to a horse's back increases its energetic costs of locomotion, but the magnitude of increase obtained by loading the most distal portion of limb has not been measured. Objective: To measure oxygen consumption in horses with mass added to the back and hooves. Because such mass distribution alters inertial parameters of the limbs, kinematic measurements were made to quantify the magnitude of change in limb movement. Methods: Steady-state oxygen consumption was measured in 6 horses with a load of 2.4 kg. The load was either carried on the back or distributed eq...
Whishaw IQ, Sacrey LA, Gorny B.An animal that has stepped over an obstacle with its forelimbs uses a memory of the obstacle to guide the hind limbs so that they also clear the obstacle, even in situations in which long pauses are introduced between forelimb and hind limb stepping. To further clarify the features of hind limb obstacle clearance memory, the present study examined hind limb obstacle clearance in the horse. A rider guided horses over obstacles and paused the horse over obstacles in tests that examined the relationship between forelimb and hind limb stepping, with the following results. First, the horses display...
Marx JO, Olsson MC, Larsson L.To fully understand the effect of scaling on skeletal muscle shortening velocity (V (0)), it is important to know which phenotypic characteristics drive the changes between species. The purpose of the current investigation was to compare the effects of body mass and femur length, as an estimate of total limb length, on V (0) in species that cover a 100,000-fold range of body masses. Using the slack test procedure, V (0) was determined for fibers expressing types I and IIa myosin heavy chain (MyHC) isoforms in the mouse, rat, dog, human, horse, and rhinoceros under identical experimental condit...
Gacem S, Valverde A, Catalán J, Yánez Ortiz I, Soler C, Miró J.This study aimed to characterize the sperm kinematic values with high frames per second, to define the subpopulation structure of a horse and a donkey and compare them. A total of 57 fresh semen ejaculates (26 Spanish and 16 Arabian horse breeds and 10 donkeys) were collected and subsequently analyzed for kinematic parameters using the Computer-aided sperm motility analysis ISAS®v1.2 system and using a Spermtrack® 10-μm depth counting chamber. Sequences were recorded at 250 frames per second, and eight kinematic parameters were automatically evaluated. All kinematic parameters showed signif...
Tassone S, Renna M, Barbera S, Valle E, Fortina R.Successful studies on in vitro digestibility measurement of feedstuffs with fecal inoculum have been reported for horses, whereas data on donkeys are currently lacking. In this study, we evaluated the use of the Daisy Incubator for in vitro digestibility measurement of feedstuffs using donkey feces as source of microbial inoculum. The method was tested using seven feedstuffs commonly used in donkey diets (alfalfa, bromegrass, ryegrass, and timothy hays; wheat bran and wheat straw; barley grains). Feces were obtained from four female donkeys, and incubations were carried out at 1-week interva...
Jäderkvist Fegraeus K, Velie BD, Axelsson J, Ang R, Hamilton NA, Andersson L, Meadows JRS, Lindgren G.The Swedish-Norwegian Coldblooded trotter and the heavier North-Swedish draught horse both descend from the North-Swedish horse, but the Coldblooded trotters have been selected for racing performance while the North-Swedish draught horse is mainly used for agricultural and forestry work. By comparing the genomes of Coldblooded trotters, North-Swedish draught horses and Standardbreds for a large number of single-nucleotide polymorphisms (SNPs), the aim of the study was to identify genetic regions that may be under selection for racing performance. We hypothesized that the selection for racing p...
Durgam S, Singh B, Cole SL, Brokken MT, Stewart M.Histological evaluation of healing tendons is primarily focused on monitoring restoration of longitudinal collagen alignment, although the elastic property of energy-storing flexor tendons is largely attributed to interfascicular sliding facilitated by the interfascicular matrix (IFM). The objectives of this study were to explore the utility of second harmonic generation (SHG) imaging to objectively assess cross-sectional tendon fascicle architecture, to combine SHG microscopy with elastin immunofluorescence to assess the ultrastructure of collagen and elastin in longitudinal and transverse se...
