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.
Ayad A, Besseboua O, Aissanou S, Stefaniuk-Szmukier M, Piórkowska K, Musiał AD, Długosz B, Kozłowska A, Ropka-Molik K.Genetic disorders are recognised as hereditary diseases with the most significant economic impact on horse breeding, causing important foal losses, costs of treatments of horses, and maintenance of the mare during the pregnancy. The Selle Francais horses are recognized in many countries and are showing great results in equestrian sports around the world (dressage, show jumping and eventing). The study aimed to detect the presence of three mutant alleles associated with inherited diseases including Fragile Foal Syndrome (FFS), Cerebellar Abiotrophy (CA), Polysaccharide Storage Myopathy (PSSM1) ...
Bartolomé E, Valera M, Fernández J, Rodríguez-Ramilo ST.The equine breeding industry for sport's performance has evolved into a fairly profitable economic activity. In particular, the Caballo de Deporte Español (CDE) is bred for different disciplines with a special focus on Show Jumping. The main aim of this study was to determine the effects of 15 years of selection and to find out whether it has been effective and adequate regarding the CDE main breeding objectives. The whole pedigree of 19,045 horses registered as CDE was used, comprising 47,884 animals (18,799 males and 29,085 females). An analysis performed to check for the pedigree completen...
Sonali , Giri SK, Unnati , Nayan V, Legha RA, Pal Y, Bhardwaj A.India has well documented horse and pony breeds; however, the population is well diversified in different geographical regions. The Myostatin gene is one of the most profoundly studied genetic components for the detection of SNP's for the performance analysis in horses. In the present study, the MSTN exon 2 partial cds were amplified, sequenced and characterized in about 60 samples of eight different breeds of Indian horses. The results indicated the transition of Thymine to Cytosine (T>C) as single nucleotide polymorphisms in the partial sequence of exon 2 of the MSTN gene at two different...
Thompson RE, Meyers MA, Veeramachaneni DNR, Pukazhenthi BS, Hollinshead FK.Organoids are a type of three-dimensional (3D) cell culture that more closely mimic the in vivo environment and can be maintained in the long term. To date, oviductal organoids have only been reported in laboratory mice, women, and cattle. Equine oviductal organoids were generated and cultured for 42 days (including 3 passages and freeze-thawing at passage 1). Consistent with the reports in mouse and human oviductal organoids, the equine oviductal organoids revealed round cell clusters with a central lumen. Developing a 3D model of the mare oviduct may allow for an increased understanding of t...
Piličiauskienė G, Kurila L, Ežerinskis Ž, Šapolaitė J, Garbaras A, Zagurskytė A, Micelicaitė V.The tradition of burying horses in Lithuania lasted from the Early Roman period until the late 14th C AD. It was the longest-lasting custom in Europe, which has left about 2000 known horse burials. This paper publishes the osteometric data and age of horses found in Lithuanian cemeteries and castles of the 3rd-14th C AD, over 200 individuals in total. These are the remains of all the horses still stored in Lithuanian institutions. The paper discusses the dynamics of horse body size in order to test previously suggested hypotheses regarding the relationship between large horse body size and its...
Derisoud E, Jouneau L, Dubois C, Archilla C, Jaszczyszyn Y, Legendre R, Daniel N, Peynot N, Dahirel M, Auclair-Ronzaud J, Wimel L, Duranthon V....Breeding a mare until she is not fertile or even until her death is common in equine industry but the fertility decreases as the mare age increases. Embryo loss due to reduced embryo quality is partly accountable for this observation. Here, the effect of mare's age on blastocysts' gene expression was explored. Day 8 post-ovulation embryos were collected from multiparous young (YM, 6-year-old, N = 5) and older (OM, > 10-year-old, N = 6) non-nursing Saddlebred mares, inseminated with the semen of one stallion. Pure or inner cell mass (ICM) enriched trophoblast, obtained by embryo bise...
Hernández-Quiroz F, Murugesan S, Flores-Rivas C, Piña-Escobedo A, Juárez-Hernández JI, García-Espitia M, Chávez-Carbajal A, Nirmalkar K....Horses are non-ruminant, herbivorous mammals, been used through history for various purposes, with a gut microbiota from cecum to the colon, possessing remarkable fermentative capacity. We studied the fecal microbiota of Azteca, Criollo, Frisian, Iberian, Pinto, Quarter and Spanish horse breeds living in Mexico by next-generation DNA sequencing of 16S rRNA gene libraries. Dominant phyla Firmicutes, Bacteroidetes, Proteobacteria, Spirochaetes, Fibrobacteres, Actinobacteria and Verrucomicrobia have different relative abundances among breeds, with contrasted alpha and beta diversities as well. He...
Lanci A, Perina F, Donadoni A, Castagnetti C, Mariella J.Dystocia as a prolonged stage II parturition (>30 min) was associated with a higher risk of complications. The hypothesis of the study was that any type of dystocia could affect the foal’s health, even when the stage II was <30 min. Clinical reports on 222 Standardbred mares and their foals hospitalized at the Veterinary Teaching Hospital of the University of Bologna from 2004 to 2020 were reviewed. Mares were divided into the Eutocia Group (165, eutocic delivery) and the Dystocia Group (57, dystocic delivery). The incidence of dystocia was 4.9%. Stage II was longer in the Dystocia Gro...
Timko KJ, Hostnik LD, Watts MR, Chen C, Bercz A, Toribio RE, Belknap JK, Burns TA.Insulin dysregulation is a hallmark of equine metabolic syndrome (EMS) and increases the risk for development of laminitis. Accurate diagnosis of insulin dysregulation is crucial for implementation of preventative strategies in this population. The objective was to assess the effects of dexamethasone administration on insulin and glucose dynamics in light-breed horses and assess the agreement of various diagnostic tests for insulin dysregulation [basal [insulin] (BI), oral sugar test (OST), and combined glucose-insulin test (CGIT)]. Fourteen adult light-breed horses. Prospective, experimental ...
da Conceição FFCB, de Mattos BHV, Sá PA, Marçola TG, da Silva GA, Teixeira HCA, Campebell RC.Due to the scarcity of information on Breton horses, the objective was to study hematobiochemical values of this breed. Blood samples were collected from 29 Bretons, males and females, of different ages, in Brasília-DF, distributed into groups, according to age, without distinction of sex (G1): animals from 4 to 9 years old (n=16) and (G2): from 10 to 26 years old (n=13). The horses were also distributed into males and females for comparisons between the sexes. Values for red blood cells, hemoglobin, creatinine, and urea were statistically higher in females. Fibrinogen was higher in males. Ly...
Gabryś J, Kij-Mitka B, Sawicki S, Kochan J, Nowak A, Łojko J, Karnas E, Bugno-Poniewierska M.The in vitro maturation (IVM) of equine oocytes is still not efficient and does not yield consistent results. The specific requirements of equine oocytes during this process are still largely unknown, which hinders the development of assisted reproductive techniques (ART) in this species. Because the ovarian follicle microenvironment supports oocytes in their acquisition of developmental competence, follicular fluid seems to be a substantial source of bioactive factors that could support the IVM process. Extracellular vesicles (EVs) are cell-secreted molecules in body fluids that are able to ...
Zandi MB, Salek Ardestani S, Vahedi SM, Mahboudi H, Mahboudi F, Meskoob A.Dareshouri, Arabian, and Akhal-Teke are 3 Middle Eastern horse breeds that have been selected for endurance and adaptation to harsh climates. Deciphering the genetic characteristics of these horses by tracing selection footprints and copy number of variations will be helpful in improving our understanding of equine breeds' development and adaptation. For this purpose, we sequenced the whole genome of 4 Dareshouri horses using Illumina Hiseq panels and compared them with publicly available whole-genome sequences of Arabian (n = 3) and Akhal-Teke (n = 3) horses. Three tests of FLK, hapFLK, and p...
Holmes TQ, Brown AF.Equestrian sports, including racing (e.g., flat, steeple-chasing, harness or donkey derby); show-jumping; cross-country; dressage; polo; polocrosse; endurance; carriage driving; vaulting and hunting; are hugely popular in the UK, and they involve a significant number of people, both as participants and spectators, and tens of thousands of equids. In this paper, we discuss animal welfare as a complex and disputed issue, clarifying what the term means and how it can be measured. We review many aspects of welfare risk to equids used for sport, addressing issues encountered throughout their lives,...
Albrizio M, Lacalandra GM, Cinone M.In this study, we defined the composition of the culture medium that yield a significant percentage of alive and functional equine spermatozoa during enough time before artificial insemination. The effects of sodium bicarbonate were analyzed in fresh and frozen semen in respect to sperm viability, capacitation, spontaneous acrosome reaction and several kinetic parameters such as total motility, progressive motility, VCL, VSL, ALH, BCF, LIN. Moreover, employing Bayk-6844 and Nifedipine, the involvement of L-type voltage-gated calcium channels in the modulation of intracellular calcium concentra...
Suchan T, Chauvey L, Poullet M, Tonasso-Calvière L, Schiavinato S, Clavel P, Clavel B, Lepetz S, Seguin-Orlando A, Orlando L.Ancient DNA preservation in subfossil specimens provides a unique opportunity to retrieve genetic information from the past. As ancient DNA extracts are generally dominated by molecules originating from environmental microbes, capture techniques are often used to economically retrieve orthologous sequence data at the population scale. Post-mortem DNA damage, especially the deamination of cytosine residues into uracils, also considerably inflates sequence error rates unless ancient DNA extracts are treated with the USER enzymatic mix prior to library construction. While both approaches have rec...
Medica AJ, Gibb Z, Sheridan A, Harrison N, Aitken RJ.MTT is a commonly used cell vitality probe, due to its ability to form insoluble formazan deposits at cellular locations of intense oxidoreductase activity. Although this response is considered a reflection of mitochondrial redox activity, extra-mitochondrial sites of MTT reduction have been recognized within the spermatozoa of several mammalian species. Therefore, the aim of this study was to determine the major sites and causative mechanisms of MTT reduction in stallion spermatozoa. Our results show that stallion spermatozoa displayed substantial mitochondrial formazan deposition, as well as...
Criscione A, Mastrangelo S, D'Alessandro E, Tumino S, Di Gerlando R, Zumbo A, Marletta D, Bordonaro S.Purosangue Orientale Siciliano, Sanfratellano and Siciliano represent the Sicilian equine genetic resource. This study aimed to investigate the genetic diversity, population structure and the pattern of autozygosity of Sicilian horse populations using genome-wide single-nucleotide polymorphism (SNP) data generated with the Illumina Equine SNP70 array. The genotyping data of 17 European and Middle East populations were also included in the study. The patterns of genetic differentiation, model-based clustering and Neighbour-Net showed the expected positioning of Sicilian populations within the w...
Harada K, Kanemitsu S, Akioka K, Fujita K, Nishi Y, Taura Y, Sasaki N.Fifty-four slaughtered horses were classified into groups having adipose tissue in the crest of the neck with or without hemorrhage (AH and NH groups, respectively). Blood biochemical tests (Alb, TP, T-bil, GOT, GPT, LDH, T-cho, and BUN) and an epidemiological survey (age, gender, weight, origin, breed, BCS, CNS, and hoof disease) were performed. T-bil tended to be high, while the other parameters were normal. Weight, BCS, and CNS were higher in the AH group (P<0.05). GOT was lower in the AH group (P<0.05). It was suspected that the horses in the AH group had lipomatosis. It was assumed ...
Hernández-Avilés C, Castaneda C, Raudsepp T, Varner DD, Love CC.Acrosomal dysfunction has been considered as a cause of subfertility in males of different species, including stallions. A subset of subfertile stallions with acrosomal dysfunction is unique because they have normal sperm quality (motility, morphology, viability, and DNA quality). The current work aims to describe the clinical characteristics of subfertile stallions that were diagnosed with Impaired Acrosomal Exocytosis (IAE) by using two high throughput methods: flow cytometry and molecular genetic analysis, and to identify the prevalence of subfertility due to IAE in stallions evaluated at T...
Data in briefApril 1, 2022
Volume 42 108123 doi: 10.1016/j.dib.2022.108123
Gmel AI, Gmel G, Weishaupt MA, Neuditschko M.This article presents the data obtained from the scoring of 24 stallions of the Franches-Montagnes (FM) horse breed by six experts of this breed. The experts scored six traits at walk and eight at trot from the video recordings of these stallions walking and trotting on a treadmill during an incremental speed test. The scores were given on a scale of one to nine. All experts scored the same videos twice (two scoring tests) with a time interval of two years, and without feedback from the first scoring. Video sequences were presented in a different order between first and second scoring. The int...
Renaudin CD, Kass PH, Bruyas JF.A table was generated, based on foetal ultrasonographic measurements in light breed mares, for each day of gestation beginning with day 100, to provide the predicted value of four biometric parameters: biparietal diameter (BPD), eye approximated volume (EyV), foetal aortic diameter (AortD) and femur length (FL). Using this table, day of gestation was successfully predicted in 23 Quarter Horses (QH) with known mating or ovulation dates. BPD, EyV and FL were the best foetal age predictors between 100- and 200-days gestation predicting within 2 weeks of the actual day of gestation, while BPD and...
Wang M, Liu Y, Bi X, Ma H, Zeng G, Guo J, Guo M, Ling Y, Zhao C.In the present study, genome-wide CNVs were detected in a total of 301 samples from 10 Chinese indigenous horse breeds using the Illumina Equine SNP70 Bead Array, and the candidate genes related to adaptability to high temperature and humidity in Jinjiang horses were identified and validated. We determined a total of 577 CNVs ranging in size from 1.06 Kb to 2023.07 Kb on the 31 pairs of autosomes. By aggregating the overlapping CNVs for each breed, a total of 495 CNVRs were detected in the 10 Chinese horse breeds. As many as 211 breed-specific CNVRs were determined, of which 64 were found in t...
Fu M, Li Y.The horse (Equus caballus) was domesticated thousands of years after dog, cattle, pig, sheep, and goat. Importantly, it represents the domestic animal that mostly impacted the development of human civilization. Its excellent loading and moving ability prompted the changes from fixed farming mode into mobile sharing mode. Accordingly, its domestication history deserves considerable attention. So far, many issues have long been controversial, due to the extinction of the closest wild relatives and the dramatic reduction of genetic diversity. With the continuous development of sequencing technolo...
Pyrek P, Siwinska N, Zak-Bochenek A.Control of body condition is an important aspect of horse management. Its correct evaluation, and the possibility of using universal indicators are of key importance for preserving the animals' wellbeing and for providing them with proper care. The objective of this study was to evaluate the agreement between body condition scores assessed by teams and individuals, using the 9-point Body Condition Score scale created by Henneke. The evaluation of a herd of 49 healthy adult Silesian horses was conducted by veterinary medicine students with adequate training in body condition assessment. Group a...
Rueda-Carrillo G, Rosiles-Martínez R, Hernández-García AI, Vargas-Bello-Pérez E, Trigo-Tavera FJ.Hoof mineral profile is important as it could affect locomotion. Factors such as body weight, sex, age, and riding disciplines affect hoof mineral profile. In Mexico and globally, studies are needed on the characterization of mineral profile of hooves and tensile strength, as this could help to prevent overgrowth or microfractures. Therefore, in the present survey, 165 samples of equine hoof cuttings from different sex, ages, breeds, and riding disciplines from different regions of Mexico were analyzed for their mineral composition, and a universal testing machine was used to measure tensile s...
Mouncey R, Arango-Sabogal JC, de Mestre AM, Foote AK, Verheyen KL.Enhanced understanding of reasons for, and timings of, mortality in Thoroughbreds prior to entering race training is warranted to provide insight into this population's health status. The aims of this study were to describe pathologies diagnosed at post-mortem (PM) examination in Thoroughbreds aged from birth to 18 months and investigate associations between age and pathology. Reports from a pathology laboratory in Newmarket, UK, were used to identify eligible cases examined between January 2006 and December 2020. Reported pathologies were extracted and categorised where appropriate. Comorbidi...
Nikitkina EV, Dementieva NV, Shcherbakov YS, Atroshchenko MM, Kudinov AA, Samoylov OI, Pozovnikova MV, Dysin AP, Krutikova AA, Musidray AA....The semen quality of stallions including sperm motility is an important target of selection as it has a high level of individual variability. However, effects of the molecular architecture of the genome on the mechanisms of sperm formation and their preservation after thawing have been poorly investigated. Here, we conducted a genome-wide association study (GWAS) for the sperm motility of cryopreserved semen in stallions of various breeds. Methods: Semen samples were collected from the stallions of 23 horse breeds. The following semen characteristics were examined: progressive motility (PM), p...
Reissmann M, Bierwolf J, Brockmann GA.In horses, a pigment dilution acting only on black eumelanin is the so-called silver coat colour, which is characterized by a chocolate-to-reddish body with a white mane and tail. Using information from other species, we focused our study on SILV as a possible candidate gene for the equine silver phenotype. A 1559-bp genomic fragment was sequenced in 24 horses, and five SNPs were detected. Two of the five SNPs (DQ665301:g.697A>T and DQ665301:g.1457C>T) were genotyped in 112 horses representing eight colour phenotypes. Both mutations were completely associated with the silver phenotype: all eum...
Bonilla-Correal S, Noto F, Garcia-Bonavila E, Rodríguez-Gil JE, Yeste M, Miro J.Aquaporins (AQPs) are transmembrane proteins found in all cells and are responsible for the transport of water and small solutes. While these proteins have been found in the spermatozoa of humans, rodents, pigs and cattle, where not only do they play a role for the regulation of sperm volume but are also related with the sperm resilience to withstand freeze-thawing procedures, their presence in stallion sperm is yet to be reported. Therefore, the objectives of this work were as follows: (i) to determine whether AQP3, AQP7 and AQP11 are present in stallion sperm and (ii) to investigate whether ...
Głazewska I, Wysocka A, Gralak B, Sell J.Polish Arabian horses are one of the oldest and the most important Arab populations in the world. The Polish Arabian Stud Book and the Genealogical Charts by Skorkowski are the main sources of information on the ancestors of Polish Arabs. Both publications were viewed as credible sources of information until the 1990s when the data regarding one of the dam lines was questioned. The aim of the current study was to check the accuracy of the pedigree data of Polish dam lines using mtDNA analysis. The analyses of a 458 bp mtDNA D-loop fragment from representatives of 15 Polish Arabian dam lines re...
Morrell JM, Johannisson A, Dalin AM, Rodriguez-Martinez H.The objective of the current study was to optimize the volumes of Androcoll-E and sperm sample used in various sizes of centrifuge tube to scale up single-layer centrifugation (SLC) for routine use in the field. Although sperm suspensions of equivalent quality were produced using Androcoll-E in small and large tubes, the sperm yield was much lower in the latter (P<0.001). In contrast, in 200-mL tubes (XL), the yields were approximately 25% higher than those for the small tubes. An increased volume (4.5 mL) of extended ejaculate in small tubes (SLC-Inc) or 15 to 18 mL extended ejaculate on 1...
Leegwater PA, Vos-Loohuis M, Ducro BJ, Boegheim IJ, van Steenbeek FG, Nijman IJ, Monroe GR, Bastiaansen JW, Dibbits BW, van de Goor LH, Hellinga I....Inbreeding and population bottlenecks in the ancestry of Friesian horses has led to health issues such as dwarfism. The limbs of dwarfs are short and the ribs are protruding inwards at the costochondral junction, while the head and back appear normal. A striking feature of the condition is the flexor tendon laxity that leads to hyperextension of the fetlock joints. The growth plates of dwarfs display disorganized and thickened chondrocyte columns. The aim of this study was to identify the gene defect that causes the recessively inherited trait in Friesian horses to understand the disease proce...
Kane AJ, Park RD, McIlwraith CW, Rantanen NW, Morehead JP, Bramlage LR.Radiography in presale examinations of TB yearlings has become standard practice in recent years. Objective: To describe the prevalence and distribution of radiographic changes in the fetlocks, carpi, tarsi, stifles and fore feet of Thoroughbred yearlings in central Kentucky when these joints were examined as part of routine pre- and post sale evaluations. Methods: Horses subjected to radiographs included the fore (n = 1127) and hind (n = 1102) fetlocks, carpi (n = 1130), tarsi (n = 1101), stifles (n = 660) and fore feet (n = 300). Radiographic changes were categorised by location and type of ...
Lindner AE.The objective of the study was to examine the validity of v(4) [velocity run under the defined conditions inducing 4 mmol/L of blood lactate concentration ([LA])] and v(200) (velocity run under the defined conditions inducing a heart rate of 200 beats/min) to differentiate performance level among Standardbred racehorses. For this purpose, 19 Standardbred trotting racehorses with differing racing time records in 2 training yards were submitted to a standardized exercise test to determine their v(4) and v(200) (6 horses of one yard only). The test consisted of 4 or more consecutive intervals dep...
Carslake HB, Pinchbeck GL, McGowan CM.The epidemiology of equine metabolic syndrome (EMS) is poorly described. Objective: To estimate the prevalence of EMS in native UK ponies and cobs in England and Wales and identify associated risk factors. Methods: Cross-sectional study. Methods: Breeders registered with UK native pony breed societies and registered riding schools and livery yards within a set radius were invited to participate. All native UK ponies and cobs aged 3-14 years and not diagnosed or being treated for conditions likely to affect insulin regulation at participating premises were eligible. Animals underwent a clinica...
Neild D, Chaves G, Flores M, Mora N, Beconi M, Agüero A.The aim of the study was to evaluate equine sperm membrane integrity using the hypoosmotic swelling (HOS) test and to correlate this test with different sperm parameters in raw and frozen thawed semen. The HOS solutions were made with fructose, sucrose, lactose and sodium citrate each at 300, 150, 100, 50 and 25 mosm. Maximum numbers of swollen spermatozoa were observed in solutions of fructose, sucrose and lactose each at 100, 50 and 25 mosm. Correlations between progressive motility, morphologically normal spermatozoa and the HOS test were r = 0.75 and r = 0.51 in raw semen and r = 0.26 and ...
Barbić L, Lojkić I, Stevanović V, Bedeković T, Starešina V, Lemo N, Lojkić M, Madić J.Equine herpesvirus type 1 (EHV-1) is a worldwide spread pathogen of horses. It can cause abortion, respiratory and neurological disease and consequentially significant economic losses in equine industries. During 2009, two outbreaks of EHV-1 were confirmed in two stud farms in Eastern Croatia. The first outbreak occurred in February following the import of 12 horses from USA, serologically negative to EHV-1 before transport. Four mares aborted in the late stage of pregnancy and one perinatal death was recorded. Other six mares showed clinical signs of myeloencephalopathy with fatal end in four...
Luciano AM, Goudet G, Perazzoli F, Lahuec C, Gérard N.The in vitro developmental competence of equine oocytes is still low in comparison with other domestic mammals. A major factor affecting the viability of cells during in vitro culture is the increased oxidative stress. Oxidative modifications could be responsible for oocyte incompetence for in vitro maturation (IVM). Cysteamine, a glutathione (GSH) synthesis enhancer, has been shown to increase intracellular GSH content and to improve embryo development when added during IVM of bovine, porcine, and ovine oocytes. The aim of the present study was (1) to determine whether equine cumulus-oocyte c...
Jung H, Roser JF, Yoon M.Spermatogonial stem cells (SSCs) continuously undergo self-renewal and differentiation to sustain spermatogenesis throughout adulthood in males. In stallions, SSCs may be used for the production of progeny from geldings after cryopreservation and therapy for infertile and subfertile stallions. Undifferentiated cell transcription factor 1 (UTF1) is a putative marker for undifferentiated spermatogonia in humans and rats. The main purposes of this study are to determine the following: 1) changes in the expression pattern of UTF1 at various reproductive stages of stallions, 2) subpopulations of sp...
Bömcke E, Gengler N, Cothran EG.In Greece, seven native horse breeds have been identified so far. Among these, the Skyros pony is outstanding through having a distinct phenotype. In the present study, the aim was to assess genetic diversity in this breed, by using different types of genetic loci and available genealogical information. Its relationships with the other Greek, as well as foreign, domestic breeds were also investigated. Through microsatellite and pedigree analysis it appeared that the Skyros presented a similar level of genetic diversity to the other European breeds. Nevertheless, comparisons between DNA-based a...
Pillet E, Duchamp G, Batellier F, Beaumal V, Anton M, Desherces S, Schmitt E, Magistrini M.Hen egg yolk is normally used as a cryoprotective agent in semen freezing extenders, but its use has sanitary and practical disadvantages. Moreover the protection afforded by egg yolk has not yet been completely elucidated. The objective of this study was to compare the egg yolk plasma fraction to whole egg yolk in stallion freezing extender. Plasma contains mainly Low Density Lipoproteins (LDL), which are widely presumed to be the cryoprotective agent in egg yolk. Plasma can be produced on an industrial scale, sterilised by gamma-irradiation and incorporated in a ready-to-use extender (our ul...
Hill EW, Fonseca RG, McGivney BA, Gu J, MacHugh DE, Katz LM.Sequence variation at the equine myostatin gene (MSTN) locus has previously been shown to have a singular genomic influence on optimum race distance in Thoroughbred racehorses. Myostatin, encoded by the MSTN gene, is a member of the TGF-β superfamily that regulates skeletal muscle development in a range of mammalian species including the horse. In the Thoroughbred, the C-allele at the g.66493737C/T SNP has been found at significantly higher frequency in subgroups of the population that are suited to fast, short distance, sprint races and also influences body composition phenotypes. We investi...
Physick-Sheard P, Kraus M, Basrur P, McGurrin K, Kenney D, Schenkel F.To assess evidence for genetic contributions to atrial fibrillation (AF) in the Standardbred horse. Methods: Equine referrals to the Ontario Veterinary College Health Sciences Centre (OVCHSC) for 1985-2009, and age and gait matched breed registry controls. Methods: Breeds presenting ≥ 5 times annually were tabulated (admission year and diagnosis; total 40,039; AF 396; no AF 39,643), and breed and year effects examined. Heritability and inbreeding coefficients were determined for Standardbred AF cases and racing contemporaries, and odds ratios for AF were calculated for frequently occurring s...
Aune A, Fenner K, Wilson B, Cameron E, McLean A, McGreevy P.Horse trainers and riders may have preconceived ideas of horse temperament based solely on the sex of the horse. A study (n = 1233) of horse enthusiasts (75% of whom had more than 8 years of riding experience) revealed that riders prefer geldings over mares and stallions. While these data may reflect different sex preferences in horses used for sport, they may also reduce the chances of some horses reaching their performance potential. Further, an unfounded sex prejudice is likely to contribute to unconscious bias when perceiving unwanted behaviours, simplistically attributing them to demograp...
Schröder W, Klostermann A, Distl O.Intense selection for speed, endurance or pulling power in the domestic horse (Equus caballus) has resulted in a number of adaptive changes in the phenotype required for elite athletic performance. To date, studies in humans have revealed a large number of genes involved in elite athletic performance, but studies in horses are rare. The horse genome assembly and bioinformation tools for genome analyses have been used to compare human performance genes with their equine orthologues, both to retrieve pathways for these genes and to investigate their chromosomal distribution. In this review, 28 c...
Guimaraes S, Arbuckle BS, Peters J, Adcock SE, Buitenhuis H, Chazin H, Manaseryan N, Uerpmann HP, Grange T, Geigl EM.Despite the important roles that horses have played in human history, particularly in the spread of languages and cultures, and correspondingly intensive research on this topic, the origin of domestic horses remains elusive. Several domestication centers have been hypothesized, but most of these have been invalidated through recent paleogenetic studies. Anatolia is a region with an extended history of horse exploitation that has been considered a candidate for the origins of domestic horses but has never been subject to detailed investigation. Our paleogenetic study of pre- and protohistoric h...
Tozaki T, Kikuchi M, Kakoi H, Hirota KI, Nagata SI.Body weight is an important trait to confirm growth and development in humans and animals. In Thoroughbred racehorses, it is measured in the postnatal, training, and racing periods to evaluate growth and training degrees. The body weight of mature Thoroughbred racehorses generally ranges from 400 to 600 kg, and this broad range is likely influenced by environmental and genetic factors. Therefore, a genome-wide association study (GWAS) using the Equine SNP70 BeadChip was performed to identify the genomic regions associated with body weight in Japanese Thoroughbred racehorses using 851 individua...
Kearns CF, McKeever KH, Kumagai K, Abe T.This study examined whether body composition was predictive of competitive success in elite standardbreds (STB). Rump fat and muscle thickness (MTH) (vastus lateralis/intermedius [VL], extensor carpi radialis [ECR]) were measured in vivo in male n=6; female n=8 by B-mode ultrasound. Percentage body fat (%fat) was calculated from rump fat. There were no gender differences for age, body mass (males 432+/-11 kg; females 443+/-13 kg), fat-free mass (FFM) (males 400+/-12 kg; females 400+/-11 kg), ECR MTH (males 61+/-2 cm; females 60+/-2 cm) or race time (RT) (males 113+/-3 s; females 114+/-2 s). Ma...
Fawcett JA, Sato F, Sakamoto T, Iwasaki WM, Tozaki T, Innan H.The domestication process of plants and animals typically involves intense inbreeding and directional selection for various traits. Here, we genotyped 370 Japanese Thoroughbred horses using the recently developed 670k SNP array and performed various genome-wide analysis also using genotype data of other horse breeds. We identified a number of regions showing interesting patterns of polymorphisms. For instance, the region containing the MC1R locus associated with chestnut coat color may have been targeted by selection for a different mutation much earlier on than the recent selection for chestn...
Frischknecht M, Neuditschko M, Jagannathan V, Drögemüller C, Tetens J, Thaller G, Leeb T, Rieder S.A cost-effective strategy to increase the density of available markers within a population is to sequence a small proportion of the population and impute whole-genome sequence data for the remaining population. Increased densities of typed markers are advantageous for genome-wide association studies (GWAS) and genomic predictions. Methods: We obtained genotypes for 54 602 SNPs (single nucleotide polymorphisms) in 1077 Franches-Montagnes (FM) horses and Illumina paired-end whole-genome sequencing data for 30 FM horses and 14 Warmblood horses. After variant calling, the sequence-derived SNP geno...
Moon S, Lee JW, Shin D, Shin KY, Kim J, Choi IY, Kim J, Kim H.Using next-generation sequencing, we conducted a genome-wide scan of selective sweeps associated with selection toward genetic improvement in Thoroughbreds. We investigated potential phenotypic consequence of putative candidate loci by candidate gene association mapping for the finishing time in 240 Thoroughbred horses. We found a significant association with the trait for Ral GApase alpha 2 (RALGAP2) that regulates a variety of cellular processes of signal trafficking. Neighboring genes around RALGAP2 included insulinoma-associated 1 (INSM1), pallid (PLDN), and Ras and Rab interactor 2 (RIN2)...
Johansson J, von Bahr-Lindström H, Jeck R, Woenckhaus C, Jörnvall H.The primary structure of the mitochondrial form of horse liver aldehyde dehydrogenase has been determined, utilizing peptide analyses and homology with other enzyme forms. The subunit exhibits N-terminal heterogeneity in size similar to that for the corresponding human mitochondrial protein, the longest form having 500 residues. Catalase was identified as a contaminant of the preparations. All four pairs within a set of aldehyde dehydrogenases can now be compared, including the same two species variants (horse and human) for both the cytosolic and mitochondrial enzyme, revealing characteristic...
Curik I, Zechner P, Sölkner J, Achmann R, Bodo I, Dovc P, Kavar T, Marti E, Brem G.While the negative effects of inbreeding and reduced heterozygosity on fecundity and survival are well established, only a few investigations have been carried out concerning their influence on morphological traits. This topic is of particular interest for a small and closed population such as the Lipizzan horse. Thus, 27 morphological traits were measured in 360 Lipizzan mares and were regressed on the individual inbreeding coefficients, as well as on the individual heterozygosity and mean squared distances (mean d(2)) between microsatellite alleles within an individual. Both individual heter...
Moridi M, Masoudi AA, Vaez Torshizi R, Hill EW.To understand the origin and genetic diversity of Iranian native horses, mitochondrial DNA (mtDNA) D-loop sequences were generated for 95 horses from five breeds sampled in eight geographical locations in Iran. Sequence analysis of a 247-bp segment revealed a total of 27 haplotypes with 38 polymorphic sites. Twelve of 19 mtDNA haplogroups were identified in the samples. The most common haplotypes were found within haplogroup X2. Within-population haplotype and nucleotide diversities of the five breeds ranged from 0.838 ± 0.056 to 0.974 ± 0.022 and 0.011 ± 0.002 to 0.021 ± 0.001 res...
The Estonian Native Horse (ENH) is a medium-size pony found mainly in the western islands of Estonia and is well-adapted to the harsh northern climate and poor pastures. The ancestry of the ENH is debated, including alleged claims about direct descendance from the extinct Tarpan. Here we conducted a detailed analysis of the genetic makeup and relationships of the ENH based on the genotypes of 15 autosomal short tandem repeats (STRs), 18 Y chromosomal single nucleotide polymorphisms (SNPs), mitochondrial D-loop sequence and lateral gait allele in DMRT3. The study encompassed 2890 horses of 61 b...
Sánchez MJ, Azor PJ, Molina A, Parkin T, Rivero JL, Valera M.Cresty neck is a relatively common morphological defect in Pura Raza Español horses and other Baroque type horse breeds, which adversely affects the breeding industry. Objective: To establish the within-breed prevalence, possible associated factors and heritability of cresty neck in Pura Raza Español horses. Methods: Cross-sectional analysis of a large worldwide database of Pura Raza Español horses. Methods: The database included evaluations of 10,929 Pura Raza Español horses from 24 countries. Cresty neck score, on a 9 point scale, girth-to-height ratio, height at the withers, length of n...
Thompson RE, Meyers MA, Veeramachaneni DNR, Pukazhenthi BS, Hollinshead FK.Organoids are a type of three-dimensional (3D) cell culture that more closely mimic the in vivo environment and can be maintained in the long term. To date, oviductal organoids have only been reported in laboratory mice, women, and cattle. Equine oviductal organoids were generated and cultured for 42 days (including 3 passages and freeze-thawing at passage 1). Consistent with the reports in mouse and human oviductal organoids, the equine oviductal organoids revealed round cell clusters with a central lumen. Developing a 3D model of the mare oviduct may allow for an increased understanding of t...
