Topic:Horse Breeds
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.
Genetic diversity of Thoroughbred horse population from Bosnia and Herzegovina based on 17 microsatellite markers. The focus of this study was on genetic diversity of TB horse population raised in B&H. Genomic DNA was genotyped by using 17 microsatellite markers. A total of 103 alleles were detected. The average number of alleles per locus was 6.059 and effective number of alleles was 3.293. Means of observed and expected heterozygosity were calculated 0.645 and 0.696, respectively. The average PIC values was 0.649 and inbreeding coefficient was 0.090. Based on all observed parameters, ASB2 locus showed the highest genetic diversity while locus HMS2 was the least diverse. These results suggest that the pop...
A highly prevalent equine glycogen storage disease is explained by constitutive activation of a mutant glycogen synthase. Equine type 1 polysaccharide storage myopathy (PSSM1) is associated with a missense mutation (R309H) in the glycogen synthase (GYS1) gene, enhanced glycogen synthase (GS) activity and excessive glycogen and amylopectate inclusions in muscle. Equine muscle biochemical and recombinant enzyme kinetic assays in vitro and homology modelling in silico, were used to investigate the hypothesis that higher GS activity in affected horse muscle is caused by higher GS expression, dysregulation, or constitutive activation via a conformational change. PSSM1-affected horse muscle had significantly higher gly...
[A case of 63,X/64,XX mosaicism in a subfertile pony mare]. The present case report describes a 6-year old subfertile pony mare, which became pregnant after the eleventh artificial insemination. The examination of the ovaries and the uterus did not reveal any abnormal clinical findings and the mare showed a regular oestrous cycle. Based on cytogenetic and molecular genetic analyses it became possible to elucidate the observed subfertility. The mosaic karyotype of the mare consisted of 63,X (20%) and 64,XX (80%) cells. A PCR analysis failed to amplify sequences from the equine SRY gene. The observed classic 63,X/64,XX mosaicism is a plausible explanatio...
[Horse, cow and reindeer were converted into arctic domestic animals]. Domestic animal production in the arctic region is often thought to be based exclusively on reindeer herding. There are, however, regions in Northern Europe and Siberia having a long tradition in rearing breeds of cattle and horse adapted to the northers conditions also. The development of these arctic animal breeds has been largely founded on old tradition rather than on the programs of breeding organizations. As a result of the selection carried out by nature and man, the domestic animals of arctic regions express characteristics that are metabolic, structural, associated with reproductive p...
Alkaline phosphatase added to capacitating medium enhances horse sperm-zona pellucida binding. Alkaline phosphatase (AP) is present in equine seminal plasma and spermatozoa, but its functional role is not fully understood yet. Being that, sperm-oocyte interaction in equine species has been reported to be enhanced at a slightly basic pH, this work aimed at verifying whether exogenous alkaline phosphatase exerts any role on stallion spermatozoa and sperm-oocyte interaction at different pHs (7.4; 8.0; 9.0). Stallion spermatozoa were capacitated in Tyrode's medium at pH 7.4, 8.0, and 9.0 for 4 hours at 38 °C, 5% CO with 2.5-IU AP (AP group) or without AP (capacitated spermatozoa group); ...
The origin of ambling horses. Horseback riding is the most fundamental use of domestic horses and has had a huge influence on the development of human societies for millennia. Over time, riding techniques and the style of riding improved. Therefore, horses with the ability to perform comfortable gaits (e.g. ambling or pacing), so-called 'gaited' horses, have been highly valued by humans, especially for long distance travel. Recently, the causative mutation for gaitedness in horses has been linked to a substitution causing a premature stop codon in the DMRT3 gene (DMRT3_Ser301STOP) [1]. In mice, Dmrt3 is expressed in spinal...
Pigment retinopathy in warmblood horses with equine degenerative myeloencephalopathy and equine motor neuron disease. A pigment retinopathy has been reported in adult horses with equine motor neuron disease (EMND) arising from chronic α-tocopherol (α-TP) deficiency. A pigment retinopathy has not been identified in horses with neuroaxonal dystrophy/equine degenerative myeloencephalopathy (NAD/EDM) that affects genetically susceptible young horses with α-TP deficiency. The objective of this report is to describe, for the first time, a pigment retinopathy in a family of α-TP-deficient Warmbloods (WB) with clinically apparent NAD/EDM or EMND. Unassigned: Twenty-five WB horses from one farm underwent complete ...
Heritability of Recurrent Exertional Rhabdomyolysis in Standardbred and Thoroughbred Racehorses Derived From SNP Genotyping Data. Recurrent exertional rhabdomyolysis (RER) in Thoroughbred and Standardbred racehorses is characterized by episodes of muscle rigidity and cell damage that often recur upon strenuous exercise. The objective was to evaluate the importance of genetic factors in RER by obtaining an unbiased estimate of heritability in cohorts of unrelated Thoroughbred and Standardbred racehorses. Four hundred ninety-one Thoroughbred and 196 Standardbred racehorses were genotyped with the 54K or 74K SNP genotyping arrays. Heritability was calculated from genome-wide SNP data with a mixed linear and Bayesian model, ...
Association between population structure and allele frequencies of the glycogen synthase 1 mutation in the Austrian Noriker draft horse. The aim of this study was to determine the allele frequency of the glycogen synthase 1 (GYS1) mutation associated with polysaccharide storage myopathy type 1 in the Austrian Noriker horse. Furthermore, we examined the influence of population substructures on the allele distribution. The study was based upon a comprehensive population sample (208 breeding stallions and 309 mares) and a complete cohort of unselected offspring from the year 2014 (1553 foals). The mean proportion of GYS1 carrier animals in the foal cohort was 33%, ranging from 15% to 50% according to population substructures based...
Risk Factors for Equine Gastric Glandular Disease: A Case-Control Study in a Finnish Referral Hospital Population. Equine gastric glandular disease (EGGD) is a term used to classify erosive and ulcerative diseases of the glandular mucosa of the equine stomach. Epidemiologic studies of risk factors for EGGD have not been reported. Objective: To determine risk factors for EGGD. Methods: Cases (n = 83) had endoscopic evidence of EGGD; controls (n = 34) included healthy horses and horses with equine squamous gastric disease (ESGD) without EGGD. Methods: Retrospective case-control study. The data were analyzed by multivariable logistic regression modeling. Analysis was performed on the full dataset. An addi...
Identification of copy number variations in three Chinese horse breeds using 70K single nucleotide polymorphism BeadChip array. Copy number variation (CNV), an essential form of genetic variation, has been increasingly recognized as one promising genetic marker in the analysis of animal genomes. Here, we used the Equine 70K single nucleotide polymorphism genotyping array for the genome-wide detection of CNVs in 96 horses from three diverse Chinese breeds: Debao pony (DB), Mongolian horse (MG) and Yili horse (YL). A total of 287 CNVs were determined and merged into 122 CNV regions (CNVRs) ranging from 199 bp to 2344 kb in size and distributed in a heterogeneous manner on chromosomes. These CNVRs were integrated with s...
Strongylids in domestic horses: Influence of horse age, breed and deworming programs on the strongyle parasite community. 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...
Evaluation of the breeding behavior of Brazilian Pony stallions. The aim of this study was to evaluate the breeding behavior of Brazilian Pony stallions during semen collection to examine the effect of age category (AC) and month of evaluation on the characteristics of breeding behavior. Nine stallions were evaluated during the breeding and non-breeding season, 5-8 (AC1) and 9-13 years (AC2) of age. The variables evaluated were reaction time (RT), mount time one (MT1) and two (MT2), mount and ejaculation time (MEjT), mounting without erection (MWEr), mounting without ejaculation (MWEj), flehmen, kicks, bites, smells, vocalizations and serum testosterone con...
Candidate gene analysis of osteochondrosis in Spanish Purebred horses. Equine osteochondrosis (OC) is a frequent developmental orthopaedic disease with high economic impact on the equine industry and may lead to premature retirement of the animal as a result of chronic pain and lameness. The genetic background of OC includes different genes affecting several locations; however, these genetic associations have been tested in only one or few populations, lacking the validation in others. The aim of this study was to identify the genetic determinants of OC in the Spanish Purebred horse breed. For that purpose, we used a candidate gene approach to study the associati...
Changes in movement symmetry over the stages of the shoeing process in military working horses. Military working horses perform a high proportion of work on road surfaces and are shod frequently to deal with high attrition rates. The authors investigate the influence of shoeing on movement symmetry as an indirect indicator of mechanical differences affecting force production between contralateral limbs. In this quantitative observational study, inertial sensor gait analysis was performed in 23 Irish sport type horses (4-21 years, 1.58-1.85 m) in full ceremonial work at the King's Troop, Royal Horse Artillery. Changes in two movement symmetry measures (SI: symmetry index; MinDiff: dif...
Single nucleotide polymorphisms of Kit gene in Chinese indigenous horses. Kit gene is a genetic determinant of horse white coat color which has been a highly valued trait in horses for at least 2,000 years. Single nucleotide polymorphisms (SNPs) in Kit are of importance due to their strong associations with melanoblast survival during embryonic development. In this study, a mutation analysis of all 21 Kit exons in 14 Chinese domestic horse breeds revealed six SNPs (g.91214T>G, g.143245T>G, g.164297C>T, g.170189C>T, g.171356C>G, and g.171471G>A), which located in 5'-UTR region, intron 6, exon 15, exon 20, intron 20, and exon 21 of the equine Kit gene, respectively. S...
Descriptive epidemiology of veterinary events in flat racing Thoroughbreds in Great Britain (2000 to 2013). To date, no large scale studies have reported race-day events requiring veterinary attention in British Thoroughbreds racing on the flat. Quantifying and describing common injuries and health conditions affecting racehorses will enable targeted risk factor analysis aimed at reducing their occurrence. Objective: To describe the type and incidence of race-day veterinary events experienced by Thoroughbred racehorses participating in flat racing in the UK. Methods: Retrospective cohort study (2000 to 2013). Methods: Veterinary events recorded by race-day veterinarians were retrieved and linked to ...
Redundant contribution of a Transient Receptor Potential cation channel Member 1 exon 11 single nucleotide polymorphism to equine congenital stationary night blindness. Congenital stationary night-blindness (CSNB) is a recessive autosomal defect in low-light vision in Appaloosa and other horse breeds. This condition has been mapped by linkage analysis to a gene coding for the Transient Receptor Potential cation channel Member 1 (TRPM1). TRPM1 is normally expressed in the ON-bipolar cells of the inner nuclear layer of the retina. Down-regulation of TRPM1 expression in CSNB results from a transposon-like insertion in intron 1 of the TRPM1 gene. Stop transcription signals in this transposon significantly reduce TRPM1 primary transcript levels in CSNB horses. Thi...
Comparison of DMRT3 genotypes among American Saddlebred horses with reference to gait. Horse owners choose whether or not to train American Saddlebred horses (ASHs) to perform the 4-beat gaits called rack and slow gait. The rack and slow gait are similar to ambling gaits shown to be associated with variation in the DMRT3 gene in other breeds but are trained rather than naturally occurring gaits. A premature stop codon in the DMRT3 gene (DMRT3_Ser301STOP) caused by the Ch23:g.22999655C>A SNP has an effect on the pattern of locomotion in horses and allows for the pacing gait and strong association with performance of ambling gaits in diverse breeds. We used horse show records to i...
Effects of aging on mitochondrial function in skeletal muscle of American American Quarter Horses. Skeletal muscle function, aerobic capacity, and mitochondrial (Mt) function have been found to decline with age in humans and rodents. However, not much is known about age-related changes in Mt function in equine skeletal muscle. Here, we compared fiber-type composition and Mt function in gluteus medius and triceps brachii muscle between young (age 1.8 ± 0.1 yr, n = 24) and aged (age 17-25 yr, n = 10) American Quarter Horses. The percentage of myosin heavy chain (MHC) IIX was lower in aged compared with young muscles (gluteus, P = 0.092; triceps, P = 0.012), while the percentages of MHC I (gl...
Mitochondrial diversity in mountain horse population from the South-Eastern Europe. It is believed that population structure of mountain horse breeds is preserved from any genetic introgression, because of their geographical isolation and specific semi-wild life style of husbandry. Till date there are no molecular data for the Balkan horses. In this study we try to give information about some autochthonous mountain horse breeds from Bulgaria. A total of 121 horses from three different mountain massifs are presented: Stara Planina (the Balkan mountain), the Rhodopes and Rila-Pirin massif were genotyped according to mitochondrial D-loop region. The results showed huge diversity...
Arterial pH and Blood Lactate Levels of Anesthetized Mongolian Khulan ( Equus hemionus hemionus) in the Mongolian Gobi Correlate with Induction Time. Research and conservation of wide-ranging wild equids in most cases necessitate capture and handling of individuals. For free-roaming Mongolian khulan ( Equus hemionus hemionus), also known as the khulan, capture involves a strenuous, high-speed chase, and physiologic responses have yet to be elucidated. We analyzed sequential arterial blood gas (ABG) samples as a proxy for respiratory and metabolic status of khulan during capture-related anesthesia. We recorded precise chase and induction times and monitored vital parameters and ABG from free-ranging khulan during anesthesia performed for GPS...
Analysis of Failure to Finish a Race in a Cohort of Thoroughbred Racehorses in New Zealand. The objective was to describe the incidence of failure to finish a race in flat-racing Thoroughbreds in New Zealand as these are summary indicators of falls, injuries and poor performance. Retrospective data on six complete flat racing seasons (n = 188,615 race starts) of all Thoroughbred flat race starts from 1 August 2005 to 31 July 2011 were obtained. The incidence of failure to finish events and binomial exact 95% confidence intervals were calculated per 1000 horse starts. The association between horse-, rider- and race-level variables with the outcomes failure to finish, pulled-up/fell an...
Distribution of coat-color-associated alleles in the domestic horse population and Przewalski’s horse. Considering the hidden mode of inheritance of some coat-color-associated alleles, we investigated the presence/absence of coat-color-associated alleles in 1093 domestic horses of 55 breeds and 20 specimens of Przewalski's horse. For coat-color genotyping, allele specific PCR, pyrosequencing and Li-Cor analyses were conducted on 12 coat-color-associated alleles of five genes. Our data provide deep insight into the distribution of coat-color-associated alleles within breeds. We found that the alleles for the basic colorations (bay, black, and chestnut) are widely distributed and occur in nearly ...
Conformation Traits and Gaits in the Icelandic Horse are Associated with Genetic Variants in Myostatin (MSTN). Many genes are known to have an influence on conformation and performance traits; however, the role of one gene, Myostatin (MSTN), has been highlighted in recent studies on horses. Myostatin acts as a repressor in the development and regulation of differentiation and proliferative growth of skeletal muscle. Several studies have examined the link between MSTN, conformation, and performance in racing breeds, but no studies have investigated the relationship in Icelandic horses. Icelandic horses, a highly unique breed, are known both for their robust and compact conformation as well as their addi...
Comparison Between Computed Tomographic Arthrography, Radiography, Ultrasonography, and Arthroscopy for the Diagnosis of Femorotibial Joint Disease in Western Performance Horses. The femorotibial joints are a common source of lameness in Western performance horses. The objective of this prospective study was to compare the radiography, ultrasonography, computed tomographic arthrography (CTA), and arthroscopy findings in horses with lameness localized to the femorotibial joints. Twenty-five stifles in 24 horses were included and were evaluated with all four of these diagnostic methods. Defects detected in femorotibial joint structures were compared between diagnostic methods using a McNemar's test to evaluate for disagreement. Cranial medial meniscotibial desmopathy was...
Classification of Horse Gaits Using FCM-Based Neuro-Fuzzy Classifier from the Transformed Data Information of Inertial Sensor. In this study, we classify four horse gaits (walk, sitting trot, rising trot, canter) of three breeds of horse (Jeju, Warmblood, and Thoroughbred) using a neuro-fuzzy classifier (NFC) of the Takagi-Sugeno-Kang (TSK) type from data information transformed by a wavelet packet (WP). The design of the NFC is accomplished by using a fuzzy c-means (FCM) clustering algorithm that can solve the problem of dimensionality increase due to the flexible scatter partitioning. For this purpose, we use the rider's hip motion from the sensor information collected by inertial sensors as feature data for the cla...
Effective population sizes in cattle, sheep, horses, pigs and goats estimated from census and herdbook data. Accurate measures of effective population sizes (Ne ) in livestock require good quality data and specialized skills for their computation and analysis. Ne can be estimated by Wright's equation Ne =4MF/(M+ F) (M, F being sires and dams, respectively), but this requires assumptions which are often not met. Total census sizes Nc of livestock breeds are collated globally. This paper investigates whether estimates of Ne can be made from Nc ; this would facilitate conservation monitoring. Some Ne methodologies avoid the assumptions of Wright's equation and permit measurement, rather than estimation,...
Cytosine methylation of sperm DNA in horse semen after cryopreservation. Semen processing may contribute to epigenetic changes in spermatozoa. We have therefore addressed changes in sperm DNA cytosine methylation induced by cryopreservation of stallion semen. The relative amount of 5-methylcytosine relative to the genomic cytosine content of sperm DNA was analyzed by ELISA. In experiment 1, raw semen (n = 6 stallions, one ejaculate each) was shock-frozen. Postthaw semen motility and membrane integrity were completely absent, whereas DNA methylation was similar in raw (0.4 ± 0.2%) and shock-frozen (0.3 ± 0.1%) semen (not significant). In experiment 2, three ej...
Genome-wide association mapping of heritable temperament variation in the Tennessee Walking Horse. Temperament is a key criterion in the selection of horses for both leisure and competitive riding to ensure optimal performance and safety. The Tennessee Walking Horse (TWH) is described as a calm, docile breed and is often used as a trail, show and pleasure horse. However, among horse owners and caretakers, there are anecdotes supporting familial and disciplinal typical behaviors and personalities. To investigate the contribution of genetics to temperament, we collected a behavior questionnaire, brief training history and identifying information for 276 TWH, as well as blood or hair samples f...