Horse breeds represent the diverse genetic and phenotypic variations found within the species Equus ferus caballus. These breeds are categorized based on characteristics such as size, conformation, coat color, and temperament, which have been selectively bred over centuries to fulfill specific roles and functions. Common classifications of horse breeds include light horses, draft horses, and ponies, each serving different purposes ranging from riding and racing to work and companionship. This page aggregates peer-reviewed research studies and scholarly articles that explore the genetics, history, and functional attributes of various horse breeds, as well as their impact on equine management and breeding practices.
Blohina NV, Khrabrova LA.Russia has a significant pedigree diversity of horse breeds with unique gene pools that are well adapted to a wide variety of harsh natural and climatic conditions, are characterized by universal performance and high productive qualities, and are of significant interest to the world horse breeding. Genetic studies of population diversity in horse breeding are very relevant, since many domestic horse breeds are under threat of extinction. Biomaterials (hair, blood, semen) from horses of 15 local breeds bred in the Russian Federation and neighboring countries (CIS) were selected for the research...
Obradovic NA, McFadden A, Martin K, Vierra M, McLoone K, Martin E, Thomas A, Everts RE, Brooks SA, Lafayette C.This paper reports three novel KIT variants likely responsible for previously unexplained white patterning phenotypes observed in three groups of horses. White spots and markings may have substantial consequences on the value and health of domesticated horses. This study aims to elucidate the genetic mechanisms underlying depigmented coat colors to aid in producing prosperous herds. Aligned whole genome sequences were manually screened to identify three polymorphisms in a family of Anglo-Arabian horses (N = 7), a family of Warmblood horses (N = 5), and a single stock-type mare with unexplained...
Moroudi RS, Mahboudi H, Mahboudi F.The Dareshouri horse breed is one of Iran's native equine breeds, originating from the Dareshouri tribe, a subgroup of the Qashqai nomads. This breed has a history spanning over 500 years. Horses of this breed have smooth nates, tall stature, raised tails and strong skeletal muscles. This is the first study to investigate the effect of genetics on athletic performance in the Dareshouri breed. For this purpose, in this study, the genotype combination of two important variants, including the rs397152648Single nucleotide polymorphism (SNP) and Short interspersed nuclear element (SINE) insertion, ...
Rykala M, Jasiak M, Niedzwiedz A.Preventing the spread of infectious diseases in horses requires breaking the chain of infection through appropriate prophylaxis. In Poland, where the horse population reached 273,006 in 2023, vaccinations are voluntary and primarily the responsibility of horse owners, with mandatory influenza vaccinations limited to sport horses. This study aimed to evaluate the vaccination status of Polish horses against infectious diseases through a survey of 980 horse owners and an analysis of 123 horse passports from slaughterhouses. Survey participants represented all provinces, predominantly owning warmb...
Lan Y, Li Y, Wang Y.In recent years, the importance of gut microbiota in digestive absorption, metabolism, and immunity has garnered increasing attention. China possess abundant horse breed resources, particularly Guizhou horses, which play vital roles in local agriculture, tourism, and transportation. Despite this, there is a lack of comparative studies on the gut microbiota of native Guizhou horses (GZH) and imported Dutch Warmblood horses (WH). To address this gap, fecal samples were collected from both GZH and WH, and 16S rRNA high-throughput sequencing was utilized to analyze the differences in their gut mic...
Mehrazin H, Sakha M, Safi S.Due to their high specificity and exclusive cardiac myocyte sensitivity, cardiac troponins T and I (cTnT, cTnI) are currently regarded as ideal biomarkers to identify cardiomyocyte damage, myocardial injury, myocardial infarction, and chronic heart failure. In fact, cTnI is considered the most reliable biomarker for diagnosing heart-related issues. This study aimed to investigate the effects of age, gender, and exercise training on serum cTnI levels and various parameters related to the cardiovascular capacity of Caspian horses. For this purpose, 50 adult Caspian horses over 3 years old, both ...
Ohmura H, Ebisuda Y, Takahashi Y, Mukai K.Pre-exercise cooling may prevent exertional heat illness in horses. We hypothesized that pre-exercise cooling before warm-up in a hot environment would not affect performance but would mitigate reductions in body weight and increases in body temperature following exercise. Six trained Thoroughbred horses were studied using a randomized, crossover design with three pre-treatments: 30-min walk on a treadmill at 1.7 m/sec (WALK), 30 min of standing (REST), and a 10-min pre-cooling shower at 26.2 ± 0.8°C (SHOWER). All horses underwent each pre-treatment, followed by a warm-up and main exercise i...
de la Cuesta-Torrado M, Velloso Alvarez A, Santiago-Llorente I, Armengou L, Nieto F, Ríos J, Cruz-López F, Jose-Cunilleras E.Equine herpesvirus myeloencephalopathy (EHM) is a persistent threat to horses, with unclear risk factors and disease severity. Objective: To evaluate risk factors, effective reproduction rate (Rt), and long-term athletic outcomes of an EHM outbreak. Methods: Retrospective study of the 2021 EHM outbreak in Valencia, Spain, examining associations between risk factors (sex, age, breed, country of origin, and vaccination status) and case fatality rate, EHM development, and odds of returning to competition using odds ratios [95% CI] and Rt via the Robert Kochs Institute method. Results: Among 191 h...
Santana ML, Franco TGB, Bignardi AB.Barrel racing is a competitive timed rodeo event that challenges horses and riders to complete a cloverleaf pattern around three barrels in the fastest time possible. In this study, we aimed to estimate the genetic parameters of barrel racing time (BRT) and evaluate the most suitable statistical model for its analysis. We compared a repeatability model and three random regression models (RRM) to analyse the longitudinal BRT data in Brazilian Quarter Horses. A total of 356,877 BRT records from 14,108 horses that competed in various events held across Brazil between 2010 and 2024 were analysed. ...
Li X, Wang Z, Zhu M, Wang B, Teng S, Yan J, Wang H, Yuan P, Cao S, Qu X, Wang Z, Zhan K, Choudhury MP, Yang X, Bao Q, He S, Liu L, Zhao P, Jiang J....Horse domestication revolutionizes human civilization by transforming transportation, agriculture, and warfare patterns. Despite extensive studies on modern domestic horse origins, the intricate demographic history and genetic signatures underlying pony size remain unexplored. Here, a high-quality genome assembly of the Chinese Debao pony is presented, and 452 qualified individuals from 64 horse breeds worldwide are extensively analyzed. The authors' results reveal the conservation of ancient components in East Asian horses and close relationships between Asian horses and Western pony lineages...
Stefaniuk-Szmukier M, Bieniek A, Ropka-Molik K, Bellone RR.Congenital stationary night blindness (CSNB) has been connected to the leopard complex spotting phenotype (LP) in various horse breeds. CSNB associated with LP is thought to be caused by a 1378 bp insertion in TRPM1, with homozygotes being nightblind and having few to no spots of pigment in their white patterned area. This study aimed to assess the prevalence of CSNB alleles in tarant-colored horses in Poland through a three-primer system for an allele-specific Polymerase Chain Reaction (PCR). The TRPM1 gene insertion was genotyped in 221 horses belonging to Małopolska, Felin and Shetland Pon...
Berglund P, Andonov S, Jansson A, Olsson C, Lundqvist T, Strandberg E, Eriksson S.In equine sports, shoes are used to protect the hooves from wear and tear. In Swedish trotting races, pulling off the shoes to race barefoot is popular because it improves racing time. Good hoof quality is essential for high-performance horses, but not all trotting horses have hooves that tolerate barefoot racing. The ability to race barefoot is a complex trait that is known to be influenced by environmental factors, but the genetic basis of this trait has not been studied. The aim of this study was to estimate genetic parameters and correlations between estimated breeding values for three nov...
Primo ALM, Assis DM, Santos VGS, de Melo LRB, da Nóbrega LD, Medeiros Dantas AF, Maciel TA.Cerebellar abiotrophy is a neurodegenerative disease that affects the Purkinje cells of the cerebellum, resulting in premature neuronal death. In horses, its occurrence has been reported mainly in the Arabian breed as a congenital mutation inherited in an autosomal recessive manner. The objective of this study was to describe the case of cerebellar abiotrophy in a Quarter Horse foal. An 8-day-old foal was treated after presenting signs of ataxia, hypermetria, difficulty maintaining a standing position, and decreased menace response. The foal was hospitalized for 26 days, received treatment wit...
Siegers EW, Parmentier JIM, Sloet van Oldruitenborgh-Oosterbaan MM, Munsters CCBM, Serra Bragança FM.Appropriate training is essential for equine athletes to improve fitness and ensure welfare. Young Friesian stallions must complete a 10-week training program for acceptance as breeding stallions. Earlier, this training program was demonstrated to induce overtraining. Unassigned: To evaluate how this training program affects stallions' trot locomotion variables in relation to fatigue. Unassigned: Prospective analytical study. Unassigned: 3 or 4 years-old (n = 16) Friesian stallions performed three ridden indoor standardized exercise tests (SETs) in week-1 (SET-I; n = 15), week-6 (SET...
Stejskalova K, Vychodilova L, Janova E, Oppelt J, Horin P.Toll-like receptors (TLRs) play important roles in innate immunity and developmental processes. Due to their nature as molecular pattern recognition receptors, their genetic diversity may reflect the effects of various pathogen pressures. Here, the extent of variability in the TLR1-6-10 gene cluster in three geographically and historically distinct breeds of horses was analysed. A genetically diverse group of representatives of 14 other horse breeds provided additional information on the variability of this gene cluster in the domestic horse. Altogether, 25 SNPs were identified in the TLR6-1-1...
Wang C, Zeng Y, Wang J, Wang T, Li X, Shen Z, Meng J, Yao X.The Yili horse is a riding-type breed that has been continuously bred independently in China. The genetics of body conformation and racing performance traits need to be comprehensively considered in making breeding decisions. This study is the first to estimate the genetic parameters of 13 body conformation and racing performance traits in Yili horses using a linear model. In total, 9937 body conformation and 2576 race records of 9100 Yili horses obtained from 1993 to 2022 were reviewed. The results showed that heritability estimates of body measurement traits were medium to high, ranging from...
Chapard L, Gorssen W, Meyermans R, Hooyberghs K, Buys N, Janssens S.Show jumping is a popular equestrian sport that requires a unique combination of jumping capacity and rideability. It has been shown that genetics play an important role in show jumping performance that has significant implications for horse breeding programmes. This gives an important opportunity for studbooks to breed horses with the potential to perform at the highest level in show jumping competitions. However, show jumping competitions are performed at various levels (from recreational to international level) but only national competition results are used by Warmblood studbooks in most ge...
Yang L, Li P, Huang X, Wang C, Zeng Y, Wang J, Yao X, Meng J.Training is essential for enhancing equine athletic performance, but the genetic mechanisms that regulate athletic performance are unknown. Therefore, this paper aims to identify candidate genes and metabolic pathways for the effects of training on equine athletic performance through multi-omics analyses. Methods: The experiment selected 12 untrained trot-type Yili horses, which underwent a 12-week professional training program. Blood samples were collected at rest before training (BT) and after training (AT). Based on their race performance, whole blood and serum samples from 4 horses were ch...
Watson WL, MacKay JRD, Dwyer CM.This study focuses on recreational horse owners in the UK and Ireland to explore the relationship between horse characteristics and welfare issues. An online questionnaire was distributed to 1501 horse owners to collect data on the owners, horses, and health/behavioural issues. Most respondents were female (98%), lived in England (56%), and did not insure their horses for veterinary costs (51%). Horses were typically over 5 years of age (96%), taller than 154 cm (55%), and mostly geldings (65%). Common welfare issues reported included lameness (26%), handling problems (11%), antisocial behavio...
Baville E, Carstanjen B, Thomas-Cancian A, Calgaro A, Bonnet N, Tiret L, Gache V, Abitbol M.Supernumerary digits, or polydactyly, have been described in various species including humans, wild and domestic animals. In horses, it represents the most common congenital limb malformation, which has only been described in isolated cases or nuclear families. Molecular aetiology has not been reported. Objective: To characterise the phenotype of a non-syndromic pre-axial polydactyly in a horse family and to decipher the inheritance pattern. Methods: Retrospective study. Methods: Forty-three members of the family including a previously reported polydactyl case were recruited. Available clinica...
Wang J, Ren W, Li Z, Ma S, Li L, Wang R, Zeng Y, Meng J, Yao X.This study aims to analyze the whole-genome DNA methylation differences in Yili horses before and after racing, with the goal of identifying differentially methylated genes associated with racing performance and exploring the epigenetic mechanisms underlying exercise in horses. Blood samples were collected from the jugular veins of the top 3 Yili horses in a 5000 m race, which included 25 competitors, both prior to and within 5 min after the race. Genomic DNA was extracted, followed by sequencing using Whole-Genome Bisulfite Sequencing (WGBS) to assess DNA methylation levels, differentially me...
Ziadi C, Demyda-Peyrás S, Valera M, Perdomo-González D, Laseca N, Rodríguez-Sainz de Los Terreros A, Encina A, Azor P, Molina A.The single-step best linear unbiased predictor (ssGBLUP) has emerged as a reference method for genomic selection in recent years due to its advantages over traditional approaches. Although its application in horses remains limited, ssGBLUP has demonstrated the potential to improve the reliability of estimated breeding values in livestock species. This study aimed to assess the impact of incorporating genomic data using single-step restricted maximum likelihood (ssGREML) on reliability (R) in the Pura Raza Española (PRE) horse breed, compared to traditional pedigree-based REML. Methods: The an...
The response to exercise following a rest period may vary among horse breeds based on the importance of the hematological and hematochemical profiles of athletic horses. Ten Standardbred and ten Italian Saddlebred mares were subjected to a 4-week training program after a seasonal rest, and hematological parameters (red blood cells-RBCs; hemoglobin-Hb; hematocrit-Hct; platelets-PLTs; platelet aggregation-AG; aggregation slope-Slope; fibrinogen-Fb), as well as Albumin (Alb) and non-esterified fatty acids (NEFAs), were analyzed. Blood samples were obtained each week during the training program fo...
Yildirim İG, Karaarslan S, Erkan A.Musculoskeletal injuries (MSI) are a major concern in the horse racing industry, often leading to career-ending outcomes. Contributing factors include conformation, limb and joint defects, hoof structure, age, and hard track surfaces. Objective: This study aimed to evaluate the distribution of MSI in Thoroughbred and Arabian racehorses during racing and training, categorised by breed and track surface. Methods: Retrospective cohort study. Methods: The data from 2018 to 2023 were collected at the Turkish Jockey Club's Şirinyer Hippodrome (38°23'03.7″ N 27°09'01.0″ E), covering 553 MSI ca...
Corbally AF, Fahey AG.Sale prices at auction significantly impact the economic return of sport horse production. This study aimed to determine factors associated with auction sales prices of sport horses at four maturity stages: foals, juveniles, young horses, and older horses. A total of 42,799 sales records from 2003 to 2022 were obtained from two Irish equine auction companies. A univariate regression model was used, and significant variables underwent multivariate analysis. Within each maturity category, factors associated with above-mean-priced horses differed from those associated with below-mean-priced horse...
Ishikawa Y, Tufa SF, Keene DR, Bächinger HP, Winand NJ.Mutations in the collagen-modifying enzyme lysyl hydroxylase 1 (LH1) cause Warmblood Fragile Foal Syndrome (WFFS) in horses. We investigated the impact of this mutation on collagen structure and function. Our results show that LH1 deficiency leads to reduced lysine hydroxylation, altered collagen fibril organization, and tissue abnormalities resembling human Ehlers-Danlos syndrome. These findings highlight the critical role of LH1 in collagen biosynthesis and provide insights into the pathogenesis of WFFS.
Crisà A, Cardinali I, Giontella A, Silvestrelli M, Lancioni H, Buttazzoni L.Lipizzan is a famous horse breed dating back to 1580 when the original stud of Lipica was established by the Hasburg Archduke Charles II. Currently, the Italian State Stud of Lipizzan Horses (ASCAL) is a conservation nucleus managed through strict mating rules where mitochondrial DNA sequences are used to verify the correct assignment of mares to a historical pedigree maternal lineage. Here, we analyzed the D-loop sequences of Lipizzan horses from the ASCAL in Monterotondo (Rome, Italy) in order to confirm their pedigree assignment to known female founder families. The concurrent investigation...
Bussiman F, Richter J, Hidalgo J, Silva FFE, Ventura RV, Carvalho RSB, Mattos EC, Ferraz JBS, Eler JP, de Carvalho Balieiro JC.Gait visual scores are widely applied to horse breeding because they are a fast and easy phenotyping strategy, allowing the numeric interpretation of a complex biological process such as gait quality. However, they may suffer from subjectivity or high environmental influence. We aimed to investigate potential causal relationships among six visual gait scores in Campolina horses. The data included 5475 horses with records for at least one of the following traits: Dissociation (Di), Comfort (C), Style (S), Regularity (R), Development (De), and Gait total Scores (GtS). The pedigree comprised thre...
Pozharskiy A, Beishova I, Nametov A, Shamshidin A, Ulyanova T, Kovalchuk A, Ulyanov V, Shamekova M, Bekova G, Gritsenko D.Horses are animals traditionally playing prominent role as both food source and working animals for Kazakh people. Zhabe horses are traditional type of indigenous Kazakh horses characterized by versatility and adaptation to conditions of Central Asia. The present work focuses on examination of genetic structure of Zhabe horses using SNP genotyping with addition of previously published data. Total 1038 individuals including 403 new samples of Zhabe horses and 42 sample of white horses 'Zhetysu Asyly' have been considered. DNA was extracted from hair roots using commercial DNA isolation kit and ...
An T, Dugarjaviin M, Han H.The Mongolian horse, one of the oldest and most genetically diverse breeds, exhibits a wide variety of coat colors and patterns, including both wild-type and unique features. A notable characteristic of dun Mongolian horses is the presence of Bider markings-symmetrical, black-mottled patterns observed on the shoulder blades. These markings are also seen in Przewalski's horses. The dun coat color, a common wild-type phenotype in domestic horses, is characterized by pigment dilution with distinct dark areas and is regulated by mutations in the gene. This study aimed to investigate the role of ...
Chaucheyras-Durand F, Sacy A, Karges K, Apper E.Horses are large non-ruminant herbivores and rely on microbial fermentation for energy, with more than half of their maintenance energy requirement coming from microbial fermentation occurring in their enlarged caecum and colon. To achieve that, the gastro-intestinal tract (GIT) of horses harbors a broad range of various microorganisms, differing in each GIT segment, which are essential for efficient utilization of feed, especially to use nutrients that are not or little degraded by endogenous enzymes. In addition, like in other animal species, the GIT microbiota is in permanent interplay with...
Pleasant RS, Suagee JK, Thatcher CD, Elvinger F, Geor RJ.Increased blood insulin levels are associated with an increased risk of pasture-associated laminitis in equids. Objective: To determine the relationship between plasma insulin, leptin, and lipid levels, and measures of oxidative stress with adiposity in mature light breed horses. Methods: 300 randomly selected light breed horses, aged 4-20 years. Methods: A random sample of horses (140 mares, 151 geldings, and 9 stallions) was drawn from the VMRCVM Equine Field Service practice client list. Evaluations occurred June 15 - August 15, 2006, with all sampling performed between 0600 and 1200 hours....
Grilz-Seger G, Neuditschko M, Ricard A, Velie B, Lindgren G, Mesarič M, Cotman M, Horna M, Dobretsberger M, Brem G, Druml T.Intensive artificial and natural selection have shaped substantial variation among European horse breeds. Whereas most equine selection signature studies employ divergent genetic population structures in order to derive specific inter-breed targets of selection, we screened a total of 1476 horses originating from 12 breeds for the loss of genetic diversity by runs of homozygosity (ROH) utilizing a 670,000 single nucleotide polymorphism (SNP) genotyping array. Overlapping homozygous regions (ROH islands) indicating signatures of selection were identified by breed and similarities/dissimilaritie...
Librado P, Fages A, Gaunitz C, Leonardi M, Wagner S, Khan N, Hanghøj K, Alquraishi SA, Alfarhan AH, Al-Rasheid KA, Der Sarkissian C, Schubert M....The horse was domesticated only 5.5 KYA, thousands of years after dogs, cattle, pigs, sheep, and goats. The horse nonetheless represents the domestic animal that most impacted human history; providing us with rapid transportation, which has considerably changed the speed and magnitude of the circulation of goods and people, as well as their cultures and diseases. By revolutionizing warfare and agriculture, horses also deeply influenced the politico-economic trajectory of human societies. Reciprocally, human activities have circled back on the recent evolution of the horse, by creating hundreds...
Lau AN, Peng L, Goto H, Chemnick L, Ryder OA, Makova KD.Despite their ability to interbreed and produce fertile offspring, there is continued disagreement about the genetic relationship of the domestic horse (Equus caballus) to its endangered wild relative, Przewalski's horse (Equus przewalskii). Analyses have differed as to whether or not Przewalski's horse is placed phylogenetically as a separate sister group to domestic horses. Because Przewalski's horse and domestic horse are so closely related, genetic data can also be used to infer domestication-specific differences between the two. To investigate the genetic relationship of Przewalski's hors...
McGivney BA, Han H, Corduff LR, Katz LM, Tozaki T, MacHugh DE, Hill EW.The Thoroughbred horse is a highly valued domestic animal population under strong selection for athletic phenotypes. Here we present a high resolution genomics-based analysis of inbreeding in the population that may form the basis for evidence-based discussion amid concerns in the breeding industry over the increasing use of small numbers of popular sire lines, which may accelerate a loss of genetic diversity. In the most comprehensive globally representative sample of Thoroughbreds to-date (n = 10,118), including prominent stallions (n = 305) from the major bloodstock regions of the w...
Timoney PJ, McCollum WH, Roberts AW, Murphy TW.The chronic carrier state was virologically confirmed in 15 thoroughbred stallions naturally infected with equine arteritis virus based on the results of test matings and, or, isolations of the virus from semen. Carrier stallions were shown to shed equine arteritis virus in the semen for at least one to two years. Existence of a short-term or convalescent carrier state was also demonstrated in five additional stallions. The frequency of the long-term carrier state in stallions naturally infected with equine arteritis virus was 35 per cent; it varied considerably between groups of stallions on ...
The Journal of heredityOctober 15, 2003
Volume 94, Issue 5 374-380 doi: 10.1093/jhered/esg079
Tozaki T, Takezaki N, Hasegawa T, Ishida N, Kurosawa M, Tomita M, Saitou N, Mukoyama H.The genetic relationships of seven Japanese and four mainland-Asian horse populations, as well as two European horse populations, were estimated using data for 20 microsatellite loci. Mongolian horses showed the highest average heterozygosities (0.75-0.77) in all populations. Phylogenetic analysis showed the existence of three distinct clusters supported by high bootstrap values: the European cluster (Anglo-Arab and thoroughbreds), the Hokkaido-Kiso cluster, and the Mongolian cluster. The relationships of these clusters were consistent with their geographical distributions. Basing our assumpti...
Rooney MF, Hill EW, Kelly VP, Porter RK.Thoroughbred horses are finely-tuned athletes with a high aerobic capacity relative to skeletal muscle mass, attributable to centuries of genetic selection for speed and stamina. Polymorphisms in the myostatin gene (MSTN), a pronounced inhibitor of skeletal muscle growth, have been shown to almost singularly account for gene-based race distance aptitude in racehorses. In Thoroughbreds, two MSTN polymorphisms, a single nucleotide variation in the first intron (SNP g.66493737C>T) and a non-coding transposable element within the promoter region (a 227 bp SINE insertion) are of particular inter...
Ablondi M, Dadousis C, Vasini M, Eriksson S, Mikko S, Sabbioni A.Horses are nowadays mainly used for sport and leisure activities, and several local breeds, traditionally used in agriculture, have been exposed to a dramatic loss in population size and genetic diversity. The loss of genetic diversity negatively impacts individual fitness and reduces the potential long-term survivability of a breed. Recent advances in molecular biology and bioinformatics have allowed researchers to explore biodiversity one step further. This study aimed to evaluate the loss of genetic variability and identify genomic regions under selection pressure in the Bardigiano breed ba...
Felkel S, Vogl C, Rigler D, Dobretsberger V, Chowdhary BP, Distl O, Fries R, Jagannathan V, Janečka JE, Leeb T, Lindgren G, McCue M, Metzger J....Analysis of the Y chromosome is the best-established way to reconstruct paternal family history in humans. Here, we applied fine-scaled Y-chromosomal haplotyping in horses with biallelic markers and demonstrate the potential of our approach to address the ancestry of sire lines. We de novo assembled a draft reference of the male-specific region of the Y chromosome from Illumina short reads and then screened 5.8 million basepairs for variants in 130 specimens from intensively selected and rural breeds and nine Przewalski's horses. Among domestic horses we confirmed the predominance of a young'c...
Bowling AT, Del Valle A, Bowling M.Through DNA sequence comparisons of a mitochondrial D-loop hypervariable region, we investigated matrilineal diversity for Arabian horses in the United States. Sixty-two horses were tested. From published pedigrees they traced in the maternal line to 34 mares acquired primarily in the mid to late 19th century from nomadic Bedouin tribes. Compared with the reference sequence (GenBank X79547), these samples showed 27 haplotypes with altogether 31 base substitution sites within 397 bp of sequence. Based on examination of pedigrees from a random sampling of 200 horses in current studbooks of the A...
Papas M, Arroyo L, Bassols A, Catalán J, Bonilla-Correal S, Gacem S, Yeste M, Miró J.This study compared the activities of four antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPX; and glutathione reductase, GSR) in the seminal plasma of stallions and jackasses. Eighteen stallion ejaculates and 24 jack ejaculates were collected through an artificial vagina. Seminal plasma was obtained by several centrifugations at 3000×g and 4 °C for 10 min, and activities of SOD, CAT, GPX and GSR were subsequently determined. We also evaluated whether the collecting season had any influence on the activities of these four enzymes in both stallions ...
McGahern A, Bower MA, Edwards CJ, Brophy PO, Sulimova G, Zakharov I, Vizuete-Forster M, Levine M, Li S, MacHugh DE, Hill EW.Equine mitochondrial DNA (mtDNA) phylogeny reconstruction reveals a complex pattern of variation unlike that seen in other large domesticates. It is likely that this pattern reflects a process of multiple and repeated, although not necessarily independent, domestication events. Until now, no clear geographic affiliation of clades has been apparent. In this study, amova analyses have revealed a significant non-random distribution of the diversity among equine populations when seven newly sequenced Eurasian populations were examined in the context of previously published sequences. The associati...
Hauswirth R, Jude R, Haase B, Bellone RR, Archer S, Holl H, Brooks SA, Tozaki T, Penedo MC, Rieder S, Leeb T.Variants in the EDNRB, KIT, MITF, PAX3 and TRPM1 genes are known to cause white spotting phenotypes in horses, which can range from the common white markings up to completely white horses. In this study, we investigated these candidate genes in 169 horses with white spotting phenotypes not explained by the previously described variants. We identified a novel missense variant, PAX3:p.Pro32Arg, in Appaloosa horses with a splashed white phenotype in addition to their leopard complex spotting patterns. We also found three novel variants in the KIT gene. The splice site variant c.1346+1G>A occur...
Seltenhammer MH, Simhofer H, Scherzer S, Zechner R, Curik I, Sölkner J, Brandt SM, Jansen B, Pehamberger H, Eisenmenger E.Equine melanomas occur most commonly in grey horses at age 5 years or more. Generally, benign and malignant melanomas are distinguished by microscopy, but a more distinct classification would be helpful. Objective: The objectives of this study were to gain further evidence concerning the occurrence of melanotic tumours, and to evaluate the impact of heredity on melanoma development. Methods: A clinical study was conducted on a defined population of 296 grey horses of Lipizzaner breed. Individuals were classified according to their stage of disease using a 0-5 scale. Heritability was estimated ...
Pesch S, Bergmann M, Bostedt H.Seminal plasma is very important for sperm metabolism as well as sperm function and survival and transport in the female genital tract. Analysis of enzyme activities and concentrations of elements can estimate integrity and function of sperm cell membranes. In man much data are available about biochemical analyses of seminal plasma. However, not many studies have been conducted in horses yet. We collected ejaculates from 72 stallions, measured the volume, obtained seminal plasma by centrifugation and examined spermatozoa with light microscopy for motility, concentration, for dead sperm and mor...
Selim A, Megahed A, Kandeel S, Alouffi A, Almutairi MM.Determination of the seroprevalence and risk factors that are associated with West Nile virus (WNV) in horses is essential for adoption of effective prevention strategies. Our objective in this study, therefore, was to determine the seroprevalence and to identify the risk factors associated with WNV infection in the most densely horse-populated governorates in Egypt. A cross-sectional study was conducted in 2018 on 930 horses, which were distributed over five governorates in the Nile delta of Egypt. The horses, which were randomly selected, were serologically tested through use of an ID screen...
Robert C, Valette JP, Pourcelot P, Audigié F, Denoix JM.A thorough knowledge of the horse's back and limb movements at different speeds is important in the design of training programmes and the prevention of speed-related injuries. The objective of this study was to investigate changes in muscle activity and kinematics of the trot with increased speed. To evaluate these effects, 4 Saddlehorses were recorded while trotting on a horizontal treadmill at speeds ranging from 3.5-6.0 m/s. The 3-D trajectories of skin markers on the left side of the horse and the dorsal midline of the trunk were established. Electrical activity was obtained simultaneously...
Promerová M, Andersson LS, Juras R, Penedo MC, Reissmann M, Tozaki T, Bellone R, Dunner S, Hořín P, Imsland F, Imsland P, Mikko S, Modrý D....For centuries, domestic horses have represented an important means of transport and served as working and companion animals. Although their role in transportation is less important today, many horse breeds are still subject to intense selection based on their pattern of locomotion. A striking example of such a selected trait is the ability of a horse to perform additional gaits other than the common walk, trot and gallop. Those could be four-beat ambling gaits, which are particularly smooth and comfortable for the rider, or pace, used mainly in racing. Gaited horse breeds occur around the glob...
Cañon J, Checa ML, Carleos C, Vega-Pla JL, Vallejo M, Dunner S.Partition of the genetic variability, genetic structure and relationships among seven Spanish Celtic horse breeds were studied using PCR amplification of 13 microsatellites on 481 random individuals. In addition, 60 thoroughbred horses were included. The average observed heterozygosity and the mean number of alleles were higher for the Atlantic horse breeds than for the Balearic Islands breeds. Only eight percentage of the total genetic variability could be attributed to differences among breeds (mean FST approximately 0.08; P < 0.01). Atlantic breeds clearly form a separate cluster from th...
Bizarria Dos Santos W, Pimenta Schettini G, Fonseca MG, Pereira GL, Loyola Chardulo LA, Rodrigues Machado Neto O, Baldassini WA, Nunes de Oliveira H....With the availability of high-density SNP panels and the establishment of approaches for characterizing homozygosity and heterozygosity sites, it is possible to access fine-scale information regarding genomes, providing more than just comparisons of different inbreeding coefficients. This is the first study that seeks to access such information for the Mangalarga Marchador (MM) horse breed on a genomic scale. To this end, we aimed to assess inbreeding levels using different coefficients, as well as to characterize homozygous and heterozygous runs in the population. Using Axiom ® Equine Genoty...
The climatic and cultural diversity of the Italian Peninsula triggered, over time, the development of a great variety of horse breeds, whose origin and history are still unclear. To clarify this issue, analyses on phenotypic traits and genealogical data were recently coupled with molecular screening. Methods: To provide a comprehensive overview of the horse genetic variability in Italy, we produced and phylogenetically analyzed 407 mitochondrial DNA (mtDNA) control-region sequences from ten of the most important Italian riding horse and pony breeds: Bardigiano, Esperia, Giara, Lipizzan, Maremm...
Kuzmina TA, Dzeverin I, Kharchenko VA.An extensive analysis of the relationships between strongylid egg shedding in domestic horses and the strongylid community structure in regard to the age of the horses, their breeds and different strategies of horse management, particularly with anthelmintic treatment programs was performed. Domestic horses (n=197) of different ages (5 months to 22 years) and of various breeds from 15 farms with different types of deworming programs were included in this study. Strongylids (totally, 82,767 specimens) were collected in vivo after deworming of the horses with the macrocyclic lactone anthelmintic...
Rambags BP, van Boxtel DC, Tharasanit T, Lenstra JA, Colenbrander B, Stout TA.In many mammalian species, reproductive success decreases with maternal age. One proposed contributor to this age-related decrease in fertility is a reduction in the quantity or functionality of mitochondria in oocytes. This study examined whether maternal age or (in vitro maturation). IVM affect the quantity of mitochondria in equine oocytes. Oocytes were collected from the ovaries of slaughtered mares categorized as young (<12 years) or aged (≥12 years) and either denuded and prepared for analysis immediately (not-IVM) or matured in vitro for 30 hours before preparation (IVM). The m...
The Journal of heredityJanuary 3, 2018
Volume 109, Issue 4 384-392 doi: 10.1093/jhered/esx114
Druml T, Neuditschko M, Grilz-Seger G, Horna M, Ricard A, Mesaric M, Cotman M, Pausch H, Brem G.Within the scope of current genetic diversity analyses, population structure and homozygosity measures are independently analyzed and interpreted. To enhance analytical power, we combined the visualization of recently described high-resolution population networks with runs of homozygosity (ROH). In this study, we demonstrate that this approach enabled us to reveal important aspects of the breeding history of the Haflinger horse. We collected high-density genotype information of 531 horses originating from 7 populations which were involved in the formation of the Haflinger, namely 32 Italian Ha...
Takai S, Ohbushi S, Koike K, Tsubaki S, Oishi H, Kamada M.The prevalence of virulent Rhodococcus equi in isolates from soil and feces of foals on a farm with endemic R. equi infections was significantly higher than that of a farm with no history of the disease. Foals bred on a farm with the endemic disease might be constantly exposed to virulent R. equi in their environment.
Ellegren H, Johansson M, Sandberg K, Andersson L.We have isolated equine microsatellites by screening a genomic library with (TG)n and (TC)n probes. TG microsatellites were found to be more abundant than TC repeats, with an estimated frequency of one per 100,000bp. Sequence analysis of eight TG-positive clones revealed varying structures of the repeat regions; perfect stretches of TG repeats, imperfect stretches of TG repeats and compound regions of TG and TC repeats. Five loci were analysed by PCR and showed extensive polymorphism; three to seven alleles and heterozygosities of 0.40-0.76 were observed when screening 20-30 unrelated individu...
Ricard A, Robert C, Blouin C, Baste F, Torquet G, Morgenthaler C, Rivière J, Mach N, Mata X, Schibler L, Barrey E.Endurance horses are able to run at more than 20 km/h for 160 km (in bouts of 30-40 km). This level of performance is based on intense aerobic metabolism, effective body heat dissipation and the ability to endure painful exercise. The known heritabilities of endurance performance and exercise-related physiological traits in Arabian horses suggest that adaptation to extreme endurance exercise is influenced by genetic factors. The objective of the present genome-wide association study (GWAS) was to identify single nucleotide polymorphisms (SNPs) related to endurance racing performance in 597 Ara...
Jagannathan V, Gerber V, Rieder S, Tetens J, Thaller G, Drögemüller C, Leeb T.Whole-genome sequencing studies are vital to gain a thorough understanding of genomic variation. Here, we summarize the results of a whole-genome sequencing study comprising 88 horses and ponies from diverse breeds at 19.1× average coverage. The paired-end reads were mapped to the current EquCab3.0 horse reference genome assembly, and we identified approximately 23.5 million single nucleotide variants and 2.3 million short indel variants. Our dataset included at least 7 million variants that were not previously reported. On average, each individual horse genome carried ∼5.7 million single n...
