Topic:Breed Differences
Breed differences in horses encompass variations in physical characteristics, behavior, and physiological traits among different horse breeds. These differences arise from selective breeding practices aimed at enhancing specific attributes such as speed, endurance, strength, or temperament. Physical attributes can include variations in size, coat color, and conformation, while behavioral traits may involve differences in temperament and trainability. Physiological differences can affect metabolism, disease susceptibility, and performance capabilities. This topic includes peer-reviewed research studies and scholarly articles that explore the genetic, environmental, and historical factors contributing to breed differences, as well as their implications for equine management, health, and performance.
Physiological response to weight carrying and associations with conformation traits in Icelandic horses used for tour riding. Weight carrying capacity is an important trait in riding horses and it may be associated with conformation. This study examined the physiological response to a ridden incremental weight carrying test in 16 adult Icelandic horses used for tour riding. Horses carried 20% (BWR20%), 25% (BWR25%), 30% (BWR30%) and 35% (BWR35%) of their body weight (BW) in tölt (~ 5.7 m/seconds, 640 m/step), and associations with body measurements and back conformation (score) were examined. Horses were divided into two groups (narrow or broad back) and body measurements were collected. Plasma lactate was analy...
The Effects of the Lactation Period, Mare Age, and Foaling on the Chemical and Physical Composition of Milk from Kazakh Mares Kept Under Natural Pasture Conditions. This study aimed to evaluate the chemical composition of milk from Kazakh mares kept under free-grazing conditions on natural pasture without supplementary feeding. Fifty Kazakh mares were aged 3 to 13 years, kept in herds, and categorized by age, number of foalings, and lactation stage for statistical analysis. Milk samples were collected, chilled, and analyzed on the same day using a Milkoscan FT2. The composition of fat, protein, lactose, total solids, casein, and other components was examined. Statistical analyses, including ANOVA, PCA, CDA, and Pearson correlation analysis, were performed...
The Thoroughbred Theory: Influence of Breed on Performance at the CCI5*-L Level of Eventing. Breed bias exists within many of the top disciplines of equestrian sport. Therefore, the objective of this study was to evaluate the influence of breed on performance at the CCI5*-L level of eventing. To do so, the results of all CCI5*-L events from 2014 to 2024 were assessed. Initially, Thoroughbreds were compared to all non-Thoroughbreds, and this was followed by assessing the ten primary breeds. Data included penalties accrued in dressage, cross country, show jumping, and overall. Additionally, the likelihood of completing each phase was assessed. It was found that Thoroughbreds accrued mor...
Prevalence and risk of orthopedic diagnoses in insured Swedish Warmblood horses. Sweden has a strong tradition of insuring horses for veterinary costs, and orthopedic diagnoses are the most common for insurance claims. The aim of this study was to investigate differences in prevalence and risk of orthopedic diagnoses for Swedish warmblood (SWB) horses classified as jumping (J) or dressage (D) horses. Also, other factors that may influence orthopedic health were investigated, i.e., sex, birth cohort, and participation in young horse tests and competition. The data consisted of 15,619 insured SWB horses born between 2010 and 2020. Horses were classified as J or D horses acco...
Genetic relationship between Neck and Limb defects in Pura Raza Española Horses. Neck and limb conformational defects can impair functionality and performance in Pura Raza Española (PRE) horses. However, their potential genetic relationship has not been previously explored. Objective: To estimate the genetic correlations between two types of neck defects (Cresty neck -CN-, Ewe neck -EN-) and twelve conformational limb defects: Forelimb (Buck knee -BUK-, Calf knee -CK-, Bench knee -BEK-, Knock knee -KK-, Splay-footed forelimb -SFF-, Pigeon-toed forelimb -PTF-), rear limb (Closed hock -CH-, Open hock -OH-, Convergent hock -CVH-, Divergent hock -DVH-, Splay-footed rear limb ...
Retrospective five-year study of equine casuistry in a Colombian perinatology center. A retrospective study was conducted at the Foal Care Equine Perinatology Center in Colombia from October 2017 to May 2023. The goal was to analyze the most frequent pathologies, as well as assess the sexes, ages, and breeds of the patients, with an emphasis on the perinatal population. Out of 945 clinical histories, 776 pertained to perinatology. Survival rates were calculated, and a descriptive analysis was performed. The overall survival rate for neonates was 73.6%, with females constituting 57% of the neonatal patients. The most prevalent breed among mares and neonates was the Creole Colomb...
Whole-Genome Resequencing Analysis of Copy Number Variations Associated with Athletic Performance in Grassland-Thoroughbred. Copy number variation (CNV) is an important source of genetic variation. However, studies utilizing whole-genome sequencing to investigate CNVs in horse populations and their effects on traits remain relatively limited. This study aims to address the lack of research on the impact of copy number variation (CNV) on racing performance in horse populations, providing new insights for locally bred racing breeds. We analyzed 60 offspring derived from the crossbreeding of Thoroughbred horses and Xilingol horses. These horses were temporarily named "Grassland-Thoroughbred" and were divided into two g...
Selection signatures and inbreeding: exploring genetic diversity in five native horse breeds. Horses have undergone extensive natural and artificial selection, shaping the diversity of breeds observed today. Native Italian breeds present unique traits influenced by natural selection, such as adaptation to harsh climates, or hoof strength, but face challenges due to population declines and the reduction of their original breeding purpose. This study focuses on five local Italian breeds: Bardigiano, Haflinger, Maremmano, Murgese, and Italian Heavy Draught Horse, to understand how selection has shaped their populations. A total of 1620 individuals were genotyped with a medium-density SNP ...
Analysis of Population Structure in Hungarian Coldblood Horses Based on Pedigree Information. The Hungarian Coldblood horse was developed in the 1920s by crossing local mares with draft horses imported from Belgium and France, and was approved as an official horse breed in 1954. The aim of the study was to analyze the quality of the pedigree, generation interval, gene origin, and inbreeding. The pedigree information was received from the Hungarian Coldblood Horse Breeding Association. The studbook data of the registered animals up to 2023 were evaluated. Two reference populations were chosen: horses having offspring in 1989 and 2023. The final database contained 21,699 horses. Pedigree...
Allele Frequencies and Genotypes for the Ryanodine Receptor 1 Variant Causing Malignant Hyperthermia and Fatal Rhabdomyolysis With Hyperthermia in Horses. Fatal anesthesia-induced malignant hyperthermia (MH) and rhabdomyolysis with hyperthermia documented in Quarter Horses (QH) breeds are caused by a missense variant in the ryanodine receptor 1 gene (RYR1: XP_023505430.1.:p.(R2454G), designated as MH). The reported cases to date have all been heterozygous, and the allele frequency is suspected to be low. Objective: To determine an accurate estimate of MH allele frequency in multiple horse breeds and investigate whether homozygous animals exist in the population. Methods: In total, 159 227 horses from 16 breeds who were either submitted for cli...
Prediction of Gestational Age in Warmblood, Standardbred and Thoroughbred Horses Based on the Table Established in Light Breed Horses Using Foetal Ultrasonographic Measurements of Four Biometric Parameters. Using the equation of Hartwig et al. and the table established for light breed horses, day of gestation was predicted in 108 Warmblood (WB) and 59 racehorses (Thoroughbred [TB] and Standardbred [STB]) pregnant mares. In WB, gestational ages were predicted within 2 weeks from 100 to 200 days of gestation using biparietal diameter (BPD), aortic diameter (AortD) or femur length (FL); within 2 weeks from 100 to 250 days using BPD or AortD; within 2 weeks from 100 to 300 days using BPD alone; and within 3 weeks from 100 to 350 days using eye approximated volume (EyV) alone. In the ...
Lipidomics and biochemical profiling of adult Yili horses in a 26 km endurance race: exploring metabolic adaptations. The equine lipid metabolism is activated during and after endurance exercise to provide energy in response to the metabolic and physiological changes in the body caused by prolonged exercise; however, the specific regulatory mechanisms remain controversial and identifying differential lipid metabolites associated with equine endurance is essential to elucidate these regulatory mechanisms. In this study, blood samples for lipid metabolomic analysis and biochemical indices were collected before and after a 26 km race from 12 Yili horses with different endurance performance. The biochemical res...
Computed tomographic measurements in 110 front hooves of non-lame Thoroughbred racehorses and Warmblood showjumpers. There are no published reference ranges on computed tomographic (CT) hoof wall and sole measurements. Objective: To establish reference ranges for CT measurements of the hoof wall and sole in non-lame horses, and to investigate associations between measurements and signalment, laterality, and medial or lateral sides. Methods: Retrospective, cross-sectional study. Methods: Soft tissue reconstructions of fan-beam CT studies of 110 front feet of 56 non-lame horses (30 Thoroughbred racehorses, 26 Warmblood showjumpers), performed in non- to semi-weightbearing positions, were analysed. Hoof wall th...
Characteristics and dynamic changes of gut microbiota in Mongolian horses and Guizhou horses. The gut microbial importance and its crucial roles in host digestion, immunity, and metabolism have received widely attention. Horses, especially indigenous varieties such as Mongolian horses (MGH) and Guizhou horses (GZH), have not received sufficient attention, and the characteristics of their gut microbiota are still unclear. For this purpose, we collected faecal samples from eight MGH and eight GZH to compare their gut microbial differences using amplicon sequencing. The results of alpha diversity analysis indicated that the gut bacterial diversity and gut fungal abundance in GZH were sign...
Pilot Study on the Profiling and Functional Analysis of mRNA, miRNA, and lncRNA in the Skeletal Muscle of Mongolian Horses, Xilingol Horses, and Grassland-Thoroughbreds. Muscle fibers, as the fundamental units of muscle tissue, play a crucial role in determining skeletal muscle function through their growth, development, and composition. To investigate changes in muscle fiber types and their regulatory mechanisms in Mongolian horses (MG), Xilingol horses (XL), and Grassland-Thoroughbreds (CY), we conducted histological and bioinformatic analyses on the gluteus medius muscle of these three horse breeds. Immunofluorescence analysis revealed that Grassland-Thoroughbreds had the highest proportion of fast-twitch muscle fibers at 78.63%, while Mongolian horses had ...
Investigating the interplay of stressors and health in horses through fecal cortisol metabolite analysis. Horses are highly sensitive to stress, which can affect their wellbeing and lead to various health issues. Effective and objective stress assessment is therefore crucial for improving their care and management. The production of the glucocorticoid cortisol is increased in response to stressful stimuli and its metabolites can be measured non-invasively in feces. Therefore, this study aimed to explore the impact of different environmental and physiological stressors on fecal cortisol metabolite (FCM) concentrations in horses, with a particular focus on the relationship between stress, health, an...
Genetic characteristics of local horse breeds by microsatellite DNA loci. 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...
Genomic insights into the genetic diversity and genetic basis of body height in endangered Chinese Ningqiang ponies. Genetic diversity in livestock and poultry is critical for adapting production systems to future challenges. However, inadequate management practices, particularly in developing countries, have led to the extinction or near extinction of several species. Understanding the genetic composition and historical background of local breeds is essential for their effective conservation and sustainable use. This study compared the genomes of 30 newly sequenced Ningqiang ponies with those of 56 other ponies and 104 horses to investigate genetic diversity, genetic differentiation, and the genetic basis o...
A Systematic Literature Review of Mitochondrial DNA Analysis for Horse Genetic Diversity. This Systematic Literature Review (SLR) consolidates current research on mitochondrial DNA (mtDNA) analysis in horses, focusing on genetic variation, maternal lineage tracing, and haplogroup identification. The article selection process screened 1380 articles, with 76 fulfilling the inclusion criteria. Data extraction covered sampling techniques, studied mtDNA regions, sequencing methods, and haplogroup identification. Following the methodology of the PRISMA guidelines, this review encompasses studies published since 2012, obtained from Scopus, PubMed, Research4Life, Web of Science, and Scienc...
Domestic Quarter Horse (Equus caballus) Milk Macronutrient Composition Analyses Within Micro Quantities from Two Different Geographical Locations. Microquantity laboratory procedures (<5 mL) are often used to analyze milk from non-bovid or less common species due to limited available samples and small sample sizes, unlike the large quantities of milk needed for macroquantity (~20 mL) assays standard in the commercial dairy industry. To better understand microquantity milk laboratory analyses, quarter horse () milk from North Carolina State University (females = 4, n = 43) and California Polytechnic State University (females = 4, n = 42) equine centers was compared to investigate differences in macronutrient composition from 4 to 130 d...
Exploration of the Differential Expression Patterns of Immunoglobulin Heavy Chain Genes in Horses and Donkeys. This study investigated the immunoglobulins (IG) gene locus structure and expression diversity in local Chinese horse and donkey breeds, including Ningqiang, Guanzhong horses, and varieties such as Guanzhong, Jiami, and Northern Shaanxi donkey using genome alignment and high-throughput sequencing. The aim was to expand understanding of IG expression patterns in horses, donkeys, and their different breeds. The results revealed that the donkey IGH locus contains 117 VH genes (23 functional), 44 DH genes, and 8 JH genes, arranged in a VH-DH-JH sequence on chromosome 7, spanning approximately 1189...
A retrospective survey of equine ocular diseases evaluated at a referral hospital in Ontario (2011 to 2021). Our objective was to investigate the demographics and prevalence of ocular disease in a large referral population of horses in Ontario over a 10-year period. Unassigned: A retrospective analysis of medical records for 283 horses evaluated by Board-certified veterinary ophthalmologists at the Ontario Veterinary College (Guelph, Ontario) was conducted. Signalment and ocular disease were recorded. Unassigned: The 3 most common ocular abnormalities identified were uveitis (43.7%, 123 horses), ulcerative keratitis (42.0%, 119 horses), and cataract (25.1%, 71 horses). Uveitis was most often secondar...
Microbiome analysis reveals dynamic changes of gut microbiota in Guizhou horse and Dutch Warmblood horses. 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...
Genomic Patterns of Homozygosity and Genetic Diversity in the Rhenish German Draught Horse. The Rhenish German draught horse is an endangered German horse breed, originally used as working horse in agriculture. Therefore, the objective of this study was to evaluate the breed's genetic diversity using pedigree and genomic data in order to analyze classical and ancestral pedigree-based inbreeding, runs of homozygosity, ROH islands, and consensus ROH. Methods: We studied the genome-wide genotype data of 675 Rhenish German draught horses and collated pedigree-based inbreeding coefficients for these horses. The final dataset contained 64,737 autosomal SNPs. Results: The average number of ...
A Retrospective Study on Pre- and Intraoperative Predictors on the Recovery Quality of Horses After General Anesthesia. Equine anesthesia is related to high morbidity and mortality rates and recent studies suggested that the period of recovery remains the phase associated with the greatest risk of mortality in horses. Intraoperative hypotension, hypoxemia, and hypercapnia are recognized as potential determinants of recovery quality. This study, conducted at the Equine University Hospital of Liege, aimed to explore how these factors influence recovery outcomes and compare complications between non-emergency and emergency procedures. We analyzed data from 1057 horses, with a mean weight of 498 kg (ranging from 15...
The Effect of Season and Breed on Hypothalamic-Pituitary-Adrenal Axis Hormones, Metabolic Hormones, and Oxidative Markers in Ponies and Horses. Endocrine function in ponies differs from horses, with seasonally increased concentrations of plasma adrenocorticotropic hormone (ACTH) and an increased risk of insulin dysregulation. Objective: (1) Season and breed differences exist in concentrations of hypothalamic-pituitary-adrenal axis and metabolic hormones; and (2) systemic oxidative status is significantly different between ponies and horses and correlates with endocrine hormones. Methods: Thirty-four healthy Welsh ponies and 14 healthy Quarter horses. Methods: Blood was collected from Welsh ponies and Quarter horses in the same region ...
High prevalence of Chorioptes bovis: an important factor in chronic progressive lymphedema in Belgian draft horses. A cross-sectional study was conducted to estimate the prevalence of chorioptic mange affecting the distal legs of horses in Belgium, focusing on the association between mange and chronic progressive lymphedema (CPL) in Belgian draft horses. Clinical examinations and skin scrapings were performed on the distal legs of 156 Belgian draft horses and 142 Belgian warmblood horses. In the Belgian draft horse breed, 144 (92.31%) horses were infested with Chorioptes bovis mites, and 126 (80.77%) displayed clinical signs of CPL. CPL prevalence in draft horses aged < 1 year was 17.86%, while mites we...
Genetic Evaluation of Barrel Racing Performance in Quarter Horses. 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. ...
Identification of Genetic Relationships and Group Structure Analysis of Yanqi Horses. The Yanqi horse is a distinguished local breed in China, known for its robust physique and strong adaptability. However, due to insufficient breeding populations and a loosely structured breeding system, the number of Yanqi horses has been declining annually. To protect its genetic resources and develop scientific breeding strategies, this study aimed to analyze the genetic diversity, parentage relationships, and genetic structure of the Yanqi horse conservation population using microsatellite markers. A total of 117 Yanqi horses were selected for genotyping analysis using 16 microsatellite ...
Genomic Insights into Post-Domestication Expansion and Selection of Body Size in Ponies. 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...