Statistical analysis in equine research involves the application of mathematical techniques to collect, review, and interpret data related to horse health, behavior, and performance. This field encompasses a variety of methods, including descriptive statistics, inferential statistics, and multivariate analysis, to identify patterns, test hypotheses, and draw conclusions from equine data. Statistical analysis aids in understanding various aspects of equine science, such as disease prevalence, treatment efficacy, genetic traits, and performance metrics. This page aggregates peer-reviewed research studies and scholarly articles that explore the methodologies, applications, and outcomes of statistical analysis in the context of equine studies.
Johnson JE, Bruce AC.The aim of the research reported in this paper was to explore empirically whether levels of participation in horserace betting are affected by the complexity of the betting task. The study employed a systematic random sample of 1161 betting decisions made in UK offcourse betting offices during 1987. The research was conducted in a naturalistic setting where it was possible to grade complexity and to measure levels of participation. Complexity was defined in terms of both the number of alternatives in the decision-maker's choice set (number of horses in a race) and the complexity of the attribu...
Popot MA, Houghton E, Ginn A, Jones M, Teale P, Samuels T, Lassourd V, Dunnett N, Cowan DA, Bonnaire Y, Toutain PL.The purpose of the present report was to estimate the population parameters of cortisol concentrations in urine, an endogenous hormone used as a 'doping' agent and for which an international threshold (1.0 micrograms/ml) has been proposed. Two data bases (French and UK) corresponding to 112 and 142 samples, respectively were considered. Urine was collected under specific post competition conditions. Cortisol concentrations were obtained by validated methods (HPLC for the French samples, and GC-MS for UK samples). No difference was observed between the 2 data sets and statistical analyses were ...
Woolf CM.Arabian bay horses manifest, on the average, more common white markings in their hind legs than their forelegs (anteroposterior asymmetry) and more common white markings in their left legs than their right legs (directional asymmetry). To determine if genetic variation exists for these types of asymmetry, the phenotypic response was studied in bay foals when their dams and sires were selected for the directions of fore-hind and left-right differences. In the fore-hind studies, the quantitative shifts in the bay foals were in the direction specified by the selection scheme and the observed devi...
Martin GS, Strand E, Kearney MT.To develop a statistical model to evaluate the influence of specific parameters on racing performance in Thoroughbreds. Methods: Survey. Methods: Racing records of Thoroughbreds performing in Louisiana from 1981 to 1985. Methods: Race results for 20 randomly selected days from 5 racetracks during 5 years were analyzed, using regression analysis. Results: The most influential parameter was distance raced. There were significant differences in racing performance among horses at different tracks. At the tracks examined, fast racing surfaces resulted in significantly faster finish times than good ...
Peck KE, Ray AC, Manuel G, Rao MM, Foos J.To develop a sensitive, rugged high-performance liquid chromatography (HPLC) method for the measurement of phenylbutazone (PBZ) in equine sera, using a rapid, nonevaporative extraction technique. Methods: Sera from 5 nonexercising adult horses. Methods: After addition of sodium chloride and acetonitrile to serum samples, reverse-phase HPLC analysis for PBZ and oxyphenbutazone (OXY) was performed directly on extracts, using diode array UV spectrophotometric detection. Probenecid was used as an internal standard. Data were evaluated by standard means of statistical analysis. Results: Recoveries ...
Gravance CG, Liu IK, Davis RO, Hughes JP, Casey PJ.The heads of stallion spermatozoa were analysed by computer automated sperm head morphometry and the morphometric values of the major subpopulations of sperm heads were assessed. The criteria for normal dimensions of stallion sperm heads are proposed based on the analysis of these measurements. Semen samples were collected from 10 fertile and 10 subfertile stallions, processed by a standard method, smeared onto microscope slides and stained using haematoxylin. At least 200 properly digitized sperm heads were analysed from each stallion. The measurements for length, width, area, perimeter and w...
Carr EA, Spier SJ, Kortz GD, Hoffman EP.Evaluate histories, clinical signs, and laboratory data of 69 horses homozygous by DNA testing for hyperkalemic periodic paralysis (HPP). Methods: Cohort study. Methods: 69 of 189 horses testing homozygous for HPP between October 1992 and November 1994. Methods: Questionnaires addressing signalment, training regimes, medical history, and current status of affected horses were sent to owners, trainers, or attending veterinarians. Data from completed questionnaires were tabulated and evaluated, using descriptive statistics. Results: Sixty-nine (37%) of 189 questionnaires were completed and retur...
Steele LL, Wilkins JR.Associations between occupational exposures and spontaneous abortion (SA) in a cohort of female veterinarians were studied with pregnancy and job-exposure history data collected as part of a mixed-mode survey of all women graduating from U.S. veterinary colleges during the 11-year period 1970-1980 (N = 2,997; response rate 85.0%). Data analysis focused on SA risks among postgraduation pregnancies in relation to 1) type of clinical practice at the time of conception and 2) self-reported occupational exposures to 13 exposure entities. Multiple logistic regression was used to control for the pote...
Estberg L, Stover SM, Gardner IA, Johnson BJ, Case JT, Ardans A, Read DH, Anderson ML, Barr BC, Daft BM, Kinde H, Moore J, Stoltz J, Woods LW.To characterize and contrast data from Thoroughbreds that incurred a fatal musculoskeletal injury (FMI; injury resulting in death or euthanasia) during racing or training and data from all California race entrants during a 9-month period in 1991. Methods: Case-control study. Methods: Thoroughbreds that incurred a FMI during racing or training at a California race-meet and all California race entrants from January through June and October through December 1991. Methods: Age and sex were compared with chi 2 and Fisher's exact tests among horses fatally injured while racing and training. A log-li...
Sandoval JA, Gil F, Arencibia A, Ayala I, Vazquez JM.By using m-ATPase techniques, under alkaline and acid pre-incubations, as well as metabolic techniques (alpha-MGPDH and NADH-TR), sections from the lumbar and costal portions of diaphragm muscle in horse and dog were analysed. Fibre samples were exposed to image-analysis observations in order to determine the lowest fibre diameter and obtain statistical data. The findings revealed that the lumbar portion of horse diaphragm consists of fibre types I, IIA and IIB; in the costal portion, the fibre type I and IIA were present. In the dog, the lumbar and costal portions consisted of fibre types I, ...
Mitten LA, Hinchcliff KW, Sams R.Evaluation of a portable blood gas analyzer, (StatPal II, Unifet, Inc, La Jolla, CA) was performed using tonometered solutions and equine blood. Samples were analyzed by the StatPal II and either an Instrument Laboratory IL1306 (Lexington, MA) or a Radiometer ABL50 blood gas analyzer (Radiometer America Inc., Westlake, OH). Comparison of the StatPal II and the IL1306 was done by analysis of 3 tonometered solutions (acidic, normal, and alkalotic) and 27 equine venous blood samples. Blood pH, PCO2, PO2, and [HCO3] values were altered by IV infusion of 5% sodium bicarbonate or exercising the hors...
Clément F, Barrey E.Variability of heart rate was analysed within a sample of 30 horses in order to determine the influence of factors (animal, age, sex and breed) associated with different behavioural patterns. The heart rate fluctuations were analysed by computing the power spectral density of a series of heartbeat intervals. A generalized linear model was used to compare the spectra and to reveal the effect of each factor: animal age, sex and breed. The scale and shape of spectral densities were significantly different between animals. This individual variability was partly explained by the sex and age effects...
Moore EH, Shelton DK, Wisner ER, Richardson ML, Bishop DM, Brock JM.To reexamine the blood patch technique in a laboratory model of lung biopsy free of confounding clinical variables. Methods: An equine model of lung biopsy was developed with an excised lobe connected to an insufflation bulb and pressure monitor. Patched and control unpatched punctures were made in the lung surface, and the pressure within the lung was raised to the maximum achievable. Whether air leakage from the puncture sites could be induced was determined and, if so, at what pressure it occurred. Results: At statistical analysis with the Kaplan-Meier test and the Cox proportional hazards ...
Mama KR, Steffey EP, Pascoe PJ.This study provides baseline information on the potential use of propofol as a general anesthetic for horses. Using a Latin square design, propofol (2, 4, and 8 mg/kg) was administered intravenously on three separate occasions to six mature horses. Information about anesthetic induction, duration, and recovery was recorded along with results of rectal temperature, heart rate, respiratory rate, pHa, PaCO2 and PaO2. Statistical analysis included a mixed model analysis of variance, a general linear model analysis and least square means test for post hoc comparisons. A P < .05 was considered si...
Tomizawa N, Nishimura R, Sasaki N, Hayashi Y, Senba H, Hara S, Kadosawa T, Takeuchi A.Morphological differences between cervical vertebrae were statistically analyzed in ataxic foals to clarify abnormal structural factors in the pathogenesis of this problem. At first, multiple regression analysis and cluster analysis were performed with 28 variables in C3-C7 of 39 control foals without lameness. As a result, there were no sex differences in the growth of all cervical vertebral sites, and the most suitable categorization of the age of the foals was 3 clusters of 8 months old or younger, 9-12 months old and 13 months old or older in any sites in the cervical vertebrae. Twenty-eig...
Kamerling SG, Owens JG.The actions of most drugs are dependent upon achieving adequate plasma concentrations. Plasma concentrations are influenced by the degree to which a drug is absorbed, distributed, metabolized and excreted. Pharmacokinetic assessment reflects changes in these variables as a function of time. Pharmacodynamics refers to specific drug effects or mechanisms of drug action. Individual drug pharmacokinetics provides information on which to base a therapeutic dose, route of administration and dosing interval. However, not all drug actions temporally correlate with plasma kinetics. To resolve this disc...
Newton-Clarke MJ, Divers TJ, Delahunta A, Mohammed HO.A study was conducted over a 12 month period to assess the specificity and sensitivity of the 'slap test', using endoscopic evaluation, in the detection of cervical spinal cord and caudal brainstem lesions in horses. Fifteen ataxic horses were subjected to the 'slap test' and subsequently examined post mortem. Twelve out of the 15 had histopathological lesions consistent with their clinical signs. Thirteen horses with no history of neurological dysfunction and no histopathological evidence of cervical spinal cord or brainstem disease were used as controls. The laryngeal adductory responses exh...
Hanson CM, Kline KH, Foreman JH.Heart scores (the arithmetic mean of the QRS durations of the three bipolar limb leads for 10 cycles) and heart weights were determined from five draft type horses and five racing type horses, and evaluated for relationships between heart score and heart size within and between the two different types of horses. Horses were killed using a captive bolt gun, and actual heart weights were recorded using an electronic digital scale. The linear regression equation for heart weight versus heart score had a significant (P 0.05) different than zero. There was no significant (P > 0.05) difference f...
Beard WL, Bramlage LR, Schneider RK, Embertson RM.Medical records for 64 Thoroughbred and 45 Standardbred horses with osteochondrosis dissecans (OCD) of the tarsocrural joint that were treated by means of arthroscopic removal of the fragments before 2 years of age and before beginning racing were reviewed. Lesion site was recorded for all horses. The other foals from the dams of these surgically treated horses (siblings) were identified from mare progeny records. Racing data, including number of starts and money won during the 2- and 3-year-old racing years were obtained from the Jockey Club and the United States Trotting Association for affe...
Howard RD, Stashak TS, Baxter GM.Two 2.5-cm2 full-thickness skin wounds were created surgically over the lateral aspect of the cannon bone of each limb of 6 horses (n = 48 wounds). Dressings evaluated were a nonadherent gauze pad (group 1); a synthetic semiocclusive dressing, (group 2); equine amnion (group 3); and a synthetic fully occlusive dressing (group 4). Wounds were assessed subjectively at each dressing change, and total wound area, area of granulation tissue, and area of epithelium in each wound were determined by computerized digital analysis of photographs of the wounds. Complete healing time (wound covered by epi...
Davis RO, Gravance CG, Casey PJ.Tissue variation in microscope slides made for spermatozoon analysis and variation introduced by the subjective techniques used to analyze these slides reduce the statistical power of studies that seek to use spermatozoon morphology to predict fertility. A simple specimen preparation method was developed to standardize stallion spermatozoon morphologic smears, and a new, automated spermatozoa morphometry instrument was used to objectively analyze the efficacy of the specimen preparation technique. The method achieved a standard spermatozoon concentration and reduced field-to-field variation in...
Troedsson MH, Wiström AO, Liu IK, Ing M, Pascoe J, Thurmond M.A method for interpreting and analysing electromyographic (EMG) data of myometrial electrical activity was established. This method was used to study EMG activity in the uterus during the various stages of the oestrus cycle in mares. Recordings were analysed from four pairs of electrodes that were surgically implanted in the myometrium of four reproductively sound mares. The electrodes were placed at the tip, middle and base of the left horn and in the uterine body. Electrical activity was monitored by a polygraph. Data were transformed to a digitized form and statistically analysed. Myometria...
Herzog B, Lindner A, Sommer H.To compare the career profiles of thoroughbred racehorses in Germany in different decades all horses which raced for the last time in the years 1966/67, 1976/77 and 1986/87 were selected from the annual report of the German Thoroughbred Racing Association. The number of racing horses increased within decades while the percentage of the horses which raced for the last time was equal in all years. It amounted yearly to about 30%. Most of the horses finished racing at three and four years of age. In 1966, 1967, 1976 and 1977 more than 50% of the horses began their career at the age of two years, ...
Sojka JE, Johnson MA, Bottoms GD.This study was conducted to investigate the effect of starting time on dexamethasone suppression test results in horses. Eight adult horses were used throughout the trial. Baseline cortisol levels were established by collecting cortisol levels twice daily, at 8:00 A.M. and 8:00 P.M. for 4 consecutive days. Morning baseline cortisol levels were 46.3 +/- 5.94 ng/ml, and evening baseline cortisol levels were 32.8 +/- 5.59 ng/ml. Although lower, the evening cortisol levels were not statistically different (P = 0.154) from the morning levels. Dexamethasone suppression tests initiated at either 9:00...
Malark JA, Peyton LC, Galvin MJ.Peritoneal fluid and blood was collected from 8 healthy adult horses. Four 1-ml aliquots of peritoneal fluid from each horse were then contaminated with 0 ml (normal), 0.05 ml (1 drop), 0.10 ml (2 drops), and 0.20 ml (4 drops) of blood from the same horse. Samples were analyzed for RBC count, nucleated blood cell count, total protein concentration, and nucleated cell differential count. Statistical analysis revealed no significant changes in nucleated cell number, nucleated cell differential, or total protein concentration in peritoneal samples contaminated with blood. The RBC count significan...
Fretz PB, Li Z.Low energy helium-neon laser irradiation was administered to full thickness skin wounds (3 cm x 3 cm) on the dorsal surface of the metacarpophalangeal/metatarsophalangeal joints and cranial surface of the tarsocrural joints of eight horses. The effects on wound healing were analyzed statistically. There were no differences (p > 0.55) observed in the rate of wound healing between the low energy laser irradiated wounds and the control wounds. There was a significant difference (p < 0.006) observed in the rate of healing between the anatomical sites. Tarsal wounds healed more rapidly than f...
Martínez-Galisteo A, Diz A, Agüera E, Vivo J.34 Andalusian foals of both sexes were divided into three age-groups (A = mean age 1 month, B = 7 months, C = 14 months). Samples of the right m. gluteus medius were stained for m-ATPase and NADH-TR in order to determine fibre type composition and size as well as the relative area occupied by each type. Results revealed no statistically significant variation in the proportion of type I fibre among the three age-groups. Significant differences were recorded, however, for type II fibres; an increase in the proportion of IIA fibres was accompanied by a decrease in IIB ones, the difference being m...
Proudman CJ.The records of 200 colic episodes, collected prospectively, over a two year period, from first opinion cases, were analysed and compared with a control sample selected at random from the same population. Analysis by colic type revealed 72% spasmodic/undiagnosed; 7% surgical; 5.5% flatulent; 5% pelvic flexure impactions; 9.5% other implications and 1% colitis. A possible predisposing cause was identified in 43% of the spasmodic/undiagnosed cases. The total incidence of colic in each age group showed no statistically significant differences from the control population. Stallions were significant...
Matthews NS, Hartsfield SM, Cornick JL, Jacobson JD, Williams JD.Measurements (n = 126) of end-tidal halothane concentrations were taken from 21 horses anesthetized for routine and emergency surgery. One hundred five paired values allowed comparison of gas samples taken near the oral end of the endotracheal tube (Y1) to samples obtained at the cuffed end of the endotracheal tube (Y2). Twenty-one paired readings were assessed to compare samples taken 25 cm beyond the cuffed end of the tube (Y3) to samples from Y1. Measurements were made at all locations at 15-minute intervals starting 30 minutes after beginning halothane. All measurements were made in tripli...
Marti E, Gerber H, Essich G, Oulehla J, Lazary S.The genetic influence on chronic hypersensitivity bronchitis (CB) was investigated in families at two studs and among half-siblings of three affected and three non-affected sires at several farms. The family members at the two studs were born and raised under the same conditions, whereas the half-siblings were kept individually under very different conditions and were exposed to various environmental factors. The diagnosis was based on long-term observations and multiple clinical examinations at each of the two studs. In the half-sibling group, the diagnosis was based on the individual history...
Rogić B, Moravčíková N, Margeta P, Štrbac L, Zorc M, Kovács M, Vostry L, Kasarda R, Posta J.Lipizzan horses, bred for over four centuries, represent a unique genetic, cultural and historic resource. This study assessed genetic diversity and population structure across seven European Lipizzan populations, with emphasis on the Bosnia and Herzegovina population. A total of 547 Lipizzan horses were genotyped using 12 microsatellite markers. The parameters of genetic variability, admixture level and migration rate were calculated. The mean number of alleles, effective number of alleles and Shannon's information index were 5.78, 3.24 and 1.31, respectively. The average fixation indices wer...
Júnior AMCA, da Silva AH, Buroxid RP, Padovan JR, Nunes AT, Poleti MD, Fukumasu H, Gobesso AAO.Intense training in athletic foals may alter fecal microbiota, highlighting the need for nutritional strategies such as hydrolyzed collagen supplementation. Objective: This study aimed to evaluate the effects of dietary hydrolyzed collagen on the fecal microbiome of weanlings in training. Methods: Twenty Mangalarga Marchador foals (206 ± 18 kg; 7 ± 1 mo age) were assigned to two groups: a supplemented group (50 g/day of hydrolyzed collagen for 180 days) and a control group. A completely randomized design with repeated measures over time was used. Foals were exercised five consecutive days pe...
Boubakeur E, Belmdjahed M.Gestation length is a key parameter in equine reproductive management, yet its variability remains poorly documented in Barb and Arabian mares under Algerian conditions. Objective: This study aims to determine gestation length in mares and to assess the influence of various factors, including breed, year of mating, mating month, mare age, parity, reproductive status, stallion and the foal's sex on gestation duration. Methods: A total of 133 mares from the National Stud Farm of Tiaret (Algeria) were monitored over the period 2021-2024. Results: The mean gestation length was 332.5 days (range: 3...
Almutairi S.Research directly examining the cognitive and academic correlates of horseback-riding in childhood remains limited. This study examined the relationships among monthly horseback-riding hours, executive function (EF), and mathematics achievement in children aged 7–9 years. A sample of 262 participants from Saudi Arabia was assessed using parent interviews and official educational records, with data collected from sports clubs and horse stables. EF was modeled as a latent construct—including organization and planning, working memory, emotion regulation, self-control, and motivation—`using ...
Laseca N, Molina A, Marshall T, González I, Poyato-Bonilla J, Valera M.Accurate parentage assignment is essential for managing livestock breeding and genetic improvement. This study evaluated a breed-specific SNP panel (375 SNPs) for the Pura Raza Española (PRE) horse, comparing its performance against the traditional STR reference panel (18 microsatellite) and the international ISAG SNP core panel (378 SNPs) across population scenarios differing in levels of inbreeding and kinship. The PRE-specific SNPs were selected from the Axiom EQUIGENE array based on high genotyping reliability (call-rate > 99%), Mendelian error minimization, Hardy-Weinberg equilibr...
Sun W, Shen Z, Cairen D, Luo P, Yao X, Meng J, Zeng Y.Body measurement traits are a direct production indicator reflecting growth status and guiding genetic selection. Identifying molecular markers associated with body measurement traits could accelerate animal breeding programs. The Yanqi horse, an important indigenous breed in Xinjiang, is primarily distributed in the Bayingolin Mongol Autonomous Prefecture. However, molecular markers linked to body measurement traits in Yanqi horses remain uncharacterized. In the present study, whole-genome resequencing was performed on 183 Yanqi horses, yielding 13,366,672 single-nucleotide polymorphisms (SNP...
de Siqueira RF, Brito LA, de Figueiredo IM, Dos Santos ACR, Dos Anjos LS.Lineage-based selection is central to the Quarter Horse industry and is often justified by the assumption that morphology determines locomotor function. However, objective evidence linking static conformation to discipline-specific locomotor behaviour under standardised conditions remains limited. Objective: To investigate whether morphological differences among Quarter Horse disciplines are associated with distinct locomotor patterns or whether locomotor function converges across disciplines despite morphological variation. Methods: Cross-sectional. Methods: Barrel racing, reining, and ranch ...
Irons A, Culwell J, Nicodemus MC, Vandiver M, North E, Cavinder C, Rios de Alvarez L, Williams T.Phenotypic characterization of traits like gait and coat color is useful for minor breed identification and conservation. The Mountain Pleasure Horse (MPH) is a minor American breed as it is listed as threatened by the Livestock Conservancy. Objective: The study objective was to utilize phenotypic characterization for identifying gait and coat color phenotype of the MPH. Methods: Gait was characterized utilizing frame-by-frame analysis to identify spatiotemporal variables of purebred horses (n = 6) performing the flat walk and saddle rack. Coat color was characterized using coat color assi...
Markowitz JS.Steeplechase jockeys compete in high-risk races requiring horses and riders to clear fixed obstacles at speed. Although rider dislodgement events are recognized hazards, their incidence and participation consequences are not well characterized. Methods: This retrospective observational study used publicly available race charts from United States National Steeplechase Association races (2023-2025). Dislodgement events were defined as falls or lost rider events. Incidence rates were calculated per 1,000 starts, and timber and hurdle races were compared using Poisson regression. Rider interruptio...
Arı HH, Duro S, Alpak H, Tulobaev A, Ceylan N, Ashyk A, Salykov R, Djordjevic M, Gündemir O.This study aimed to evaluate sexual dimorphism in Kyrgyz horse skulls by separating size and shape components using Mosimann log-shape ratios, based on 18 linear cranial measurements recorded from 39 specimens. Raw linear data were analyzed alongside size-corrected Mosimann log-shape ratios to distinguish overall size from size-independent shape. Males showed larger raw means than females for all 18 variables, and 14 measurements remained significant after false-discovery-rate correction. The strongest raw differences involved skull length to nasale, total skull length, nasal length, breadth b...
Janura M, Šigutová A, Lantelme-Faisan V, Honzíková L, Bizovská L.Equine Assisted Physiotherapy (EAPT; formerly known as hippotherapy) is known to improve functional mobility, gross motor skills, and postural stability in individuals with Down syndrome (DS). However, it may be challenging to implement as a long-term intervention. The aim of the current study was to assess whether even a single session of EAPT can have effect on postural stability in children with DS. Methods: Nine children with DS underwent a single session of EAPT. Postural stability before and immediately after the EAPT session was assessed with the bipedal stance (variability of lower tru...
Witt J, Ashenefe Wassie B, Tadesse TA, Wakane WZ, Adane AT, Deressa SG, Mor SM.Ethiopia has not only one of the largest livestock populations in Africa, but also a substantial growing human population, increasing the risk of zoonotic disease transmission. Anthrax is a priority zoonosis in Ethiopia due to its risks to both human and animal health. Utilising 13 years of retrospective data (2008-2020) from 92 zones, this study investigated the spatio-temporal distribution of livestock anthrax cases in Ethiopia. High variability in annual incidence was observed, with the lowest number of cases (n=2357, 3.73 %) in 2018 followed by the highest number of cases (n=8210, 12.98 %)...
Próchniak T.The aim of this study was to pilot the assessment of sport predispositions in warmblood horse breeds, both domestic and foreign, and to evaluate factors influencing their performance. Data from 293 horses (725 starts) competing in national Grand Prix events with obstacle heights of 140-145 cm were analysed using general mixed models. The origins of Polish Halfbred Horses were examined, and correlations between results in the Young Horse Championships and later Grand Prix performance were assessed. Results showed that performance is significantly influenced by genetic factors, such as breed and...
Marlowe JL, Hughes L, Barrey E, Leeb T, Bellone R, McCue ME, Durward-Akhurst S. Advances in whole-genome sequencing (WGS) technology have led to the widespread adoption of WGS for investigating genetic diseases and traits in domestic animals. This has created a need for improved methods for prioritizing candidate causal variants. One way variants are prioritized is using variant annotators that predict variant effects based on their proximity to genomic features and effect on amino acid sequence. However, validation of variant annotators for domestic animal genomes is lacking. In this study, we calculated the agreement of three popular variant annotators, Ensembl Varian...
Bou T, Ding W, Gong W, Li Z, Shi X, Dugarjaviin M, Bai D, Yang L.The Grassland Xichun horse is an emerging crossbred population developed from Xilingol mares and Thoroughbred stallions in Inner Mongolia, China, yet its blood physiological profile has not been systematically characterized. In this study, we compared 32 hematological and serum biochemical parameters between 177 Grassland Xichun horses and 35 Xilingol horses maintained under the same extensive grazing conditions. Following Benjamini-Hochberg FDR correction, 17 of 32 parameters differed significantly between breeds. Grassland Xichun horses showed markedly higher RBC count (9.145 vs 7.905 × 10...
Shojaei B, Mousanejad E, Afshar FK, Pourjafari F.Morphological variation in equine limb dimensions provides valuable insight into breed-specific characteristics, with biometric parameters serving as reliable tools for such evaluations. Unassigned: This study aimed to provide a quantitative characterization of the external morphology of the limbs in Iranian Arab horses. Unassigned: Morphometric data were collected from 30 adult specimens of this breed, encompassing key anatomical measurements: scapula length, arm length, forearm length, metacarpus length, forepastern length, metacarpus circumference, femur length, gaskin length, metatarsus le...
Cullen E, Carslake HB, Henderson I, Stoneham S, Pinchbeck GL, Archer DC.Broodmares are at increased risk of gastrointestinal colic. However, colic risk factors specific to this population have not been investigated. Objective: To investigate horse- and management-level risk factors for post-partum colic in a cohort of Thoroughbred broodmares in the United Kingdom and Ireland. Methods: Prospective, nested case-control study. Methods: Twenty-nine Thoroughbred stud farms in the United Kingdom and Ireland were recruited, and 1044 mares were followed over the 2021 and/or 2022 foaling seasons. Data were collected on signalment, medical and management history for post-pa...
Delecave Dias T, Hauser RG, Cleary KB, Durward-Akhurst S.Arrhythmias can cause poor performance and sudden death in horses. Long-term (>24 h) electrocardiogram (ECG) monitoring has been used to identify arrhythmias in humans and is superior to short-term monitoring for transient arrhythmia detection. Televet is the current equine gold-standard ECG device. The Cardea SOLO™ (CS) is a single-use monitor with automated ECG analysis software allowing ECG monitoring for 7 days. Objective: Our objective was to validate the performance of the CS compared to the Televet. Methods: Method validation. Methods: ECGs were performed on 12 healthy horses s...
Cranston N, Buckley P, Rose L, Loy J, Randle H.Weaning is a stressful time in a foal's (Equus caballus) life. As humans artificially manage weaning in domestic horses, it provides an opportunity to safeguard horse welfare early in life, with potential long-term benefits. While numerous studies have examined the effects of different weaning and management interventions on foal stress, optimal weaning practices have yet to be identified. Overall purpose of the study: To identify which weaning interventions and management practices have the greatest potential to improve foal welfare based on physiological and behavioural outcomes. Research qu...
Takahashi K, Mukai K, Shirai T, Ebisuda Y, Sugiyama F, Yoshida T, Hatta H, Kitaoka Y.This study investigated whether different pacing patterns during high-intensity exercise elicit distinct transcriptional responses in equine skeletal muscle. Eight Thoroughbred horses completed two treadmill exercise sessions in a randomized crossover design. In the positive-pacing condition, horses exercised at 110% maximal O₂ uptake (V˙O₂max) for 1 min followed by 90% V˙O₂max for 1 min, whereas in the negative-pacing condition, the order was reversed. At 4 h after exercise, the positive-pacing protocol resulted in upregulation of 1,989 genes and downregulation of 840 genes, whereas t...
Bordignon V, Buratini J, Cue RI, Barrilari V, Gonçalves MA, Merlini G, Fernandes CB, Squires E, Pontes JHF, Fleury PDC.Equine OPU‑ICSI supports commercial IVEP, yet substantial variability persists. We retrospectively analyzed a large dataset generated in Brazil spanning Quarter Horses, Warmbloods, and Mangalarga to evaluate whether predictors previously identified in the literature show comparable patterns under distinct ecological and breeding conditions. Overall oocyte and embryo outcomes were aligned with broadly reported trends from previous studies. Oocytes retrieved from estrous mares bearing a dominant follicle exhibited higher maturation and blastocyst rates. Stallion effects segregated into distinc...
Santana ML, Bignardi AB.Resilience, defined as the capacity to maintain consistent performance under variable conditions, has emerged as a relevant breeding objective in livestock systems, yet remains largely unexplored in equine populations. The objectives of this study were to (1) derive indicators of resilience from longitudinal barrel racing time (BRT) records in Brazilian Quarter Horses, (2) estimate genetic parameters for these indicators, and (3) quantify their genetic relationships with BRT and accumulated career earnings (ACE). The dataset comprised BRT records from barrel racing events held between 2010 and...
Gao Y, Luo Z, Dong Z, Li S.Equine colic remains one of the leading causes of mortality in horses, with timely diagnosis and accurate prognostic assessment being critical for clinical decision-making. In recent years, artificial intelligence (AI) has been increasingly applied to support diagnostic and prognostic evaluation in veterinary medicine. However, the scope, methodological characteristics, and performance of AI models in equine colic have not been systematically mapped. Therefore, this scoping review was conducted to summarize current AI applications in equine colic, identify commonly used algorithms, describe re...
Khanahmadi A, Rahimi Mianji G, Moradi Shahrebabak H, Hafezian SH, Zandi MB.Breakthroughs in genomic technologies have enabled the formulation of methods to identify genomic variation in domestic animal species. Detection of the variation is necessary because it is associated with breed characteristics and economic importance in domestic animal genetics. Unassigned: This study aimed to identify the genomic regions in Turkmen and Kurdish horse breeds that have been the target of different selections over many years. It also sought to locate the genes and Quantitative trait loci (QTL) in these regions that contributed to the differentiation of these two breeds or the di...
Satué K, Fazio E, Colomer-Selva R, Damiá Giménez E, Cravana C, La Fauci D.Lactation and parity are physiological factors influencing platelet (PLT) indices, yet their combined effects in mares remain poorly characterized. As a dynamic process, lactation involves metabolic and endocrine changes that may influence thrombopoiesis; therefore, reproductive history and lactation stage may modulate PLT indices. Objective: To characterize longitudinal platelet (PLT) indices during early lactation in mares and evaluate the influence of parity on thrombopoietic responses. Methods: Fifty-five clinically healthy Spanish Purebred mares were included (20 primiparous and 25 multip...
Demeyere M, Dufourni A, Verhaeghe LM, Vernemmen I, De Backer T, van Loon G, Decloedt A.Mitral valve regurgitation (MR) is frequently detected in horses, but its classification and prognostication remain challenging. This study investigated whether auscultatory findings and left atrial function are associated with MR severity. Methods: Fifty controls (no/trivial MR) and 101 MR horses (58 mild, 36 moderate, seven severe) were retrospectively evaluated. All were in sinus rhythm and underwent auscultation and echocardiography. Mitral regurgitation severity was graded using a scoring system. Systolic murmur characteristics (duration, type and grade) were recorded. Left atrial functio...
Asadollahpour Nanaei H, Seguin-Orlando A, Negara K, MacLeod JN, Kalbfleish T, Orlando L.The Thoroughbred horse is a legacy of centuries of selective breeding for speed, emerging from the admixture of British mares and imported Oriental stallions. While previous work explored its genetic diversity, inbreeding, and selection signatures, the breed demographic and selection dynamics during the 20-century remain poorly understood. Here, we sequenced the genome of Phar Lap, a late-1920s/early-1930s racing champion, and analyzed the largest time-series of Thoroughbred whole-genome sequences, within a global panel of 850 horse genomes. Demographic modeling reveals a marked decline in gen...
Allen SE, Taylor S, Given J, Verheyen KLP.Horse falls are an important safety and welfare concern in jump racing, as they are associated with an increased risk of equine fatality and injury, as well as jockey injury. Objective: To identify risk factors for horse falls in British jump racing. Methods: Retrospective cohort. Methods: All jump race starts made on British racecourses between January 2010 and April 2023 were considered. Available horse, race, racecourse, trainer and jockey data were collated and combined with faller data recorded in official databases. Horses that were 'brought down' by another horse were not considered a f...
Gong Y, Liu X, Zheng Z, Zeng S, Zhang Y, Pu Y, Pan J, Ma Y, Jiang L.The selection of horses has been instrumental in shaping long-range mobility, advancing warfare strategies, and diversifying equine phenotypes. However, the structural variants (SVs) favored by this process remain largely unexplored. Utilizing high-fidelity Pacific Biosciences sequencing, we assembled three high-quality horse genomes, incorporating 237 Mb (9.48%) of novel sequences relative to the existing reference genome. These assemblies achieved an average Benchmarking Universal Single-Copy Orthologs completeness of 95.1%. By employing a graph-based approach, we genotyped 23,163 high-con...
Young LM, Courtney ER, Freeland RB.The racing outcome of horses that have undergone surgical repair of neonatal rib fractures is not well documented. Objective: To evaluate the impact of surgical repair of neonatal rib fractures on subsequent sales and racing performance in Thoroughbreds. Methods: Retrospective cohort study. Methods: Medical records of neonatal Thoroughbreds that underwent surgical repair of rib fractures at a referral hospital between 2014 and 2025 were reviewed. Sales and racing data were obtained from publicly available databases. Outcomes assessed included sale price at weanling and yearling sales, total ca...
