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.
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...
Genetic testing as a tool for diagnosis of congenital stationary night blindness (CSNB) in white spotted breeds in Poland. 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...
Age is associated with the requirement for surgery in horses with nephrosplenic ligament entrapment of the large colon at a single UK equine referral hospital. Conservative and surgical management of left dorsal displacement and nephrosplenic ligament entrapment of the large colon (NSLE) is well described in horses. Whilst breed factors predispose the development of NSLE, it is unknown if breed affects the likelihood for surgical intervention. Objective: To compare the incidence of surgical intervention and differences in pre-operative parameters between Thoroughbred and non-Thoroughbred horses. The authors hypothesise a higher proportion of Thoroughbreds require surgical intervention. Methods: Retrospective cross-sectional study. Methods: Case recor...
Effect of the intrinsic and extrinsic factors on the growth and development of young foals under subtropical conditions of Pakistan. This study was designed to explore the impact of intrinsic (breed of foal, age of dam, and age of foal at weaning) and extrinsic (season of birth and housing type) factors on the growth and survival of foals in the subtropical conditions of Pakistan. For the growth study, retrospective data analysis of foals (n = 150) born from purebred brood mares of Thoroughbred, Arabs, and Percheron breeds (n1, n2, and n3 = 50 each) was made. Six hundred and twenty-four (n = 624) foals born between 2020 to 2022 were observed for the study of foal survival rate. The survival of these foals till the age of on...
Genetics of Muscle Disease. In the field of equine muscle disorders, many conditions have a genetic basis. Therefore, genetic testing is an important part of the diagnostic evaluation. Validated genetic tests are currently available for 5 equine muscle disorders: hyperkalemic periodic paralysis, malignant hyperthermia, glycogen branching enzyme disease, type 1 polysaccharide storage myopathy, and myosin heavy chain myopathy. These diseases should be tested for in the appropriate breeds with clinical signs of disease or as part of breeding management. Genetic testing in veterinary medicine is not regulated, and therefore,...
Inherited non-syndromic polydactyly in a Berber and Arabian-Berber horse family. 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...
Skin Barrier in Normal and Allergic Horses: What Do We Know? Information on skin barrier in horses is limited. A study on the epidermal ultrastructure of normal and allergic horses documented disorganized amorphous intercellular lipids in the stratum corneum of allergic samples. These findings are similar to atopic canine and human skin. Currently, there is no published study comparing skin barrier function parameters between normal and allergic horses; thus, the functional implications of the ultrastructural changes are unknown. In normal horses, body location, gender, breed, and ambient conditions affect skin barrier parameters, such as Transepidermal...
Dynamic Adaptation of Hematological Parameters, Albumin, and Non-Esterified Fatty Acids in Saddlebred and Standardbred Horses During Exercise. 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...
Genome wide landscaping of copy number variations for horse inter-breed variability. Copy number variations (CNVs) have become widely acknowledged as a significant source of genomic variability and phenotypic variance. To understand the genetic variants in horses, CNVs from six Indian horse breeds, namely, Manipuri, Zanskari, Bhutia, Spiti, Kathiawari and Marwari were discovered using Axiom™ Equine Genotyping Array. These breeds differed in agro-climatic adaptation with distinct phenotypic characters. A total of 2668 autosomal CNVs and 381 CNV regions (CNVRs) were identified with PennCNV tool. DeepCNV was employed to re-validate to get 883 autosomal CNVs, of which 9.06% were...
Serum 25(OH) Vitamin D Concentrations in Horses: Effects of Age, Gender, Breed, Skin Colour and Season. The optimal amount of vitamin D required for the proper functioning of the immune system differs from the amount necessary for bone homeostasis. Furthermore, vitamin D metabolism varies among horses. Nevertheless, there is a dearth of information regarding reference values for vitamin D in horses, particularly in the Turkmen breed. The primary objectives of this study were to determine the concentrations of 25-hydroxyvitamin D (25(OH)Vit D) in Turkmen, Thoroughbred and mixed Turkmen × Thoroughbred horses and to explore the effects of various factors on it and its relationship with serum bio...
Evaluating Forelimb and Hindlimb Joint Conformation of Morna Racehorses (Equus caballus). Measuring limb joint angles is crucial for understanding horse conformation, performance, injury diagnosis, and prevention. While Thoroughbred horses have been extensively studied, local Pakistani breeds (e.g., Morna racehorse) have not received scientific attention. This study aimed to quantify normal angles of limb joints in the Morna breed. Limb joint angles of standing horses (n = 50) were quantified using a measuring tape, height stick, protractor scale, and goniometer. The mean and standard deviation (Mean ± SD) values for the forelimb joint angles were 123.02 ± 3.46° for elbow, 171.5...
Factors associated with the selling price of sport horses in public auctions in Ireland. 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...
Real-time transrectal ultrasonographic measurement of the fetal eye (vitreous body) to predict parturition in bucking horse mares. Monitoring gestation and predicting parturition in mares with unknown breeding dates is challenging, especially in pasture bred herds of bucking horses. Transrectal ultrasonographic measurement of fetal vitreous body length is a validated predictor of foaling dates, but previous research suggested a need for breed-specific parameters to develop accurate indices for respective breeds. This study aimed to develop a scale associating fetal vitreous body length with days before parturition (DBP) in bucking horses. Biannual data collection over 2 years identified 199 pregnancies out of 240 reproduc...
Genomic-Inbreeding Landscape and Selection Signatures in the Polo Argentino Horse Breed. Analyzing genetic variability and inbreeding trends is essential for effective breed management in animal populations. To this, the characterization of runs of homozygosity (ROH) provides a good genomic approach to study the phenomena. The Polo Argentino (PA) breed, globally recognized as the best adapted to playing polo, is known for its strong influence of Thoroughbreds, intense selective breeding, and extensive use of reproductive biotechnologies. This study investigates the PA's genomic variability, by characterizing the ROH landscape and identifying ROH islands (ROHi) as potential genomic...
A Genetic Make Up of Italian Lipizzan Horse Through Uniparental Markers to Preserve Historical Pedigrees. 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...
Bayesian Recursive and Structural Equation Models to Infer Causal Links Among Gait Visual Scores on Campolina Horses. 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...