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.
Changes of mRNA, miRNA and lncRNA expression contributing to skeletal muscle differences between fetus and adult Mongolian horses. The growth and development of myofibers, as the fundamental units comprising muscle tissue, and their composition type are indeed among the most crucial factors influencing skeletal muscle types. Muscle fiber adaptation is closely associated with alterations in physiological conditions. Muscle fiber types undergo dynamic changes in fetus and adult horses. Our aim is to investigate the mechanisms influencing the differences in muscle fiber types between fetal and adult stages of Mongolian horses. The study investigated the distribution of muscle fiber types within longissimus dorsi muscle of fe...
Using high-density SNP data to unravel the origin of the Franches-Montagnes horse breed. The Franches-Montagnes (FM) is the last native horse breed of Switzerland, established at the end of the 19th century by cross-breeding local mares with Anglo-Norman stallions. We collected high-density SNP genotype data (Axiom™ 670 K Equine genotyping array) from 522 FM horses, including 44 old-type horses (OF), 514 European Warmblood horses (WB) from Sweden and Switzerland (including a stallion used for cross-breeding in 1990), 136 purebred Arabians (AR), 32 Shagya Arabians (SA), and 64 Thoroughbred (TB) horses, as introgressed WB stallions showed TB origin in their pedigrees. The aim of ...
Evaluation of vasovagal tonus index and electrocardiographic parameters in horses using a new modified base apex lead method. Vasovagal tonus index (VVTI) serves as a straightforward assessment tool for autonomic function during both physiological and pathological conditions, including pregnancy, in horses. Obtaining VVTI through a modified base apex lead system could be a practical and comfortable solution. In this study, we assessed VVTI in horses with respect to training status and electrocardiographic measurements utilizing a novel modified base apex lead technique. Unassigned: A total of 12 Thai native crossbred horses and 12 Arabian horses, all free of cardiac abnormalities, were enrolled in the study. Animals ...
Ancient Mitochondrial Genomes Provide New Clues in the History of the Akhal-Teke Horse in China. This study analyzed ancient DNA from the remains of horses unearthed from the Shihuyao tombs. These were found to date from the Han and Tang Dynasties in Xinjiang (approximately 2200 to 1100 years ago). Two high-quality mitochondrial genomes were acquired and analyzed using next-generation sequencing. The genomes were split into two maternal haplogroups, B and D, according to a study that included ancient and contemporary samples from Eurasia. A close genetic affinity was observed between the horse of the Tang Dynasty and Akhal-Teke horses according to the primitive horse haplotype G1. Histori...
Genomic analyses of withers height and linear conformation traits in German Warmblood horses using imputed sequence-level genotypes. Body conformation, including withers height, is a major selection criterion in horse breeding and is associated with other important traits, such as health and performance. However, little is known about the genomic background of equine conformation. Therefore, the aim of this study was to use imputed sequence-level genotypes from up to 4891 German Warmblood horses to identify genomic regions associated with withers height and linear conformation traits. Furthermore, the traits were genetically characterised and putative causal variants for withers height were detected. Results: A genome-wide ...
Neck pain but not neurologic disease occurs more frequently in horses with transposition of the ventral lamina from C6 to C7. To determine reasons for horses to have neck radiographs performed, the incidence of transposition of the ventral lamina of C6 onto C7 (TC67), and the final diagnoses for all horses. Our hypotheses were to find a similar incidence of TC67, as has been previously reported, and an increased incidence of neck pain and dysfunction in horses with TC67. Methods: 135 horses. Methods: Retrospective observational study. Medical records of 135 horses with cervical vertebral column radiographs between 2020 and 2022 were assessed. Patient signalment, reasons for radiographs, radiographic findings, and dia...
Molecular cytogenetic screening of sex chromosome abnormalities in young horse populations. Chromosomal abnormalities occur in the equine population at a rate of approximately 2%. The use of molecular cytogenetic techniques allows a more accurate identification of chromosomal abnormalities, especially those with a low rate of abnormal metaphases, demonstrating that the actual incidence in equine populations is higher. Objective: Estimation of the number of carriers of karyotypic abnormalities in a sample from a population of young horses of various breeds, using molecular cytogenetic techniques. Methods: Cross-sectional. Methods: Venous blood samples were collected from 500 young hor...
The use of genomic assisted selection could allow early selection among Thoroughbreds and Polo Argentino horses for practicing polo. The Polo Argentino (PA) horse is a recognized breed, developed originally by mixing crossbred and Thoroughbred (TB) horses to play polo. Early PA selection is difficult due to unreliable performance estimations. This study investigated the usefulness of genomic markers previously linked to morphological and functional traits as a tool for the early selection of PA. To this, we genotyped 520 PA and 30 TB horses using the Equine GGPArray (Illumina, n=71,778 SNPs). Analyses included a genetic characterization of six genetic markers associated with behavioral (DRD4), muscular development (MSTN), a...
Current insights into equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy. Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (eNAD/EDM) is an inherited neurodegenerative disease associated with vitamin E deficiency in the first year of life. It is the second most common cause of spinal ataxia in horses euthanized for neurologic disease. Equine NAD/EDM is characterized by neurologic signs including a symmetric proprioceptive ataxia (> grade 2/5) and a wide-base stance at rest. There are currently no antemortem tests for eNAD/EDM in any breed. Conclusive diagnosis requires postmortem histologic evaluation of the brainstem and spinal cord at necropsy....
Radiological measurements of the feet of normal Straight Egyptian Arabian horses in Qatar. The Arabian horse has been identified as carrying a risk locus for equine metabolic syndrome, predisposing this breed to development of laminitis. Radigraphy of the equine foot is widely considered the main diagnostic imaging technique for evaluation of the laminitic horse. Knowledge of 'normal' breed values allows assessment of the degree and severity of radiological changes associated with laminitis. The objective of this study was to investigate the normal values for radiological measurements of the feet of the Straight Egyptian Arabian horse in Qatar. The design was a clinical prospective ...
Comparison of hematologic variables among Warmbloods, Thoroughbreds, and Western stock horse breeds. Hematology is a diagnostic tool used to evaluate the health status of horses. However, breed differences are often not considered. Objective: The objective was to compare complete blood count variables among Warmbloods, Thoroughbreds, and stock horses (SH). Methods: Ninety-six healthy horses were grouped by breed (Warmbloods, Thoroughbreds, and SH). Samples were collected through venipuncture for complete blood count analysis. One-way ANOVA with Tukey's tests or Kruskal-Wallis with Dunn's post hoc tests were used to compare hematologic variables among groups. Results: Warmbloods had a signific...
Predicted genetic burden and frequency of phenotype-associated variants in the horse. Disease-causing variants have been identified for less than 20% of suspected equine genetic diseases. Whole genome sequencing (WGS) allows rapid identification of rare disease causal variants. However, interpreting the clinical variant consequence is confounded by the number of predicted deleterious variants that healthy individuals carry (predicted genetic burden). Estimation of the predicted genetic burden and baseline frequencies of known deleterious or phenotype associated variants within and across the major horse breeds have not been performed. We used WGS of 605 horses across 48 breeds ...
Osseous pathologic changes in the lumbar region of the equine vertebral column: A descriptive post-mortem study in three breeds. Data on equine lumbar pathology hardly exist in breeds other than Thoroughbreds. Objective: To describe pathological changes of the osseous lumbar vertebral column in Warmblood horses, Shetland ponies and Konik horses. Methods: Descriptive post-mortem study. Methods: The lumbar vertebral columns of 34 Warmblood horses, 28 Shetland ponies, and 18 Konik horses were examined by computed tomography (CT). Osteoarthritis (OA) of articular processes (APJs), OA of intertransverse joints (ITJs), intervertebral disc (IVD) mineralisation, impingement of spinous (SPs) and transverse (TPs) processes and sp...
Unravelling of the genetic diversity, population structure, and phylogenetic relationships of the indigenous horse breeds of Pakistan. The current study aimed to evaluate the genetic diversity, level of admixture, and phylogenetic relationship, of the Pakistani horse breeds, along with their morphological characterization. Data for the body measurements showed that Morna horses had the highest values of body height, body length, chest girth, leg length, and head length, whereas the Baluchi horses had the lowest values for these traits. For the genetic diversity 64 animals, 15/breed except for Baluchi(14) and Topras(05), were genotyped by using the 17-plex equine genotyping kit. The AMOVA results showed that 13% of genetic div...
Factors associated with insulin responses to oral sugars in a mixed-breed cohort of ponies. Serum insulin concentration at 60 min (InsulinT60) during an oral sugar test (OST) indicates future laminitis risk and insulin dysregulation (ID). Associations between InsulinT60 and physical and owner-reported variables may help clinicians select individuals for ID testing. Associations between InsulinT60 and other metabolic markers may help elucidate ID pathophysiology. Objective: To describe associations between (A) season, physically-apparent and owner-reported factors and binary InsulinT60 interpretation (initial models) and (B) variables included in the initial models, other metabolic ...
Genetic characterisation of the Connemara pony and the Warmblood horse using a within-breed clustering approach. The Connemara pony (CP) is an Irish breed that has experienced varied selection by breeders over the last fifty years, with objectives ranging from the traditional hardy pony to an agile athlete. We compared these ponies with well-studied Warmblood (WB) horses, which are also selectively bred for athletic performance but with a much larger census population. Using genome-wide single nucleotide polymorphism (SNP) and whole-genome sequencing data from 116 WB (94 UK WB and 22 European WB) and 36 CP (33 UK CP and 3 US CP), we studied the genomic diversity, inbreeding and population structure of th...
Electrocardiographic Reference Values in Clinically Healthy Lusitano Horses. The Lusitano horse is gaining popularity in the equestrian world, and as a result, the significance of applied sports medicine for this breed is growing. As cardiology plays a crucial role in this field, numerous studies have been conducted to establish electrocardiographic reference values in various breeds to ensure a more accurate evaluation. However, studies regarding healthy Lusitano horses are lacking. So, this study aimed to establish electrocardiographic reference values for Lusitano horses, utilizing a sample of 82 clinically healthy animals. The evaluation involved lead II and base-a...
Y-Chromosome Haplotype Report among Eight Italian Horse Breeds. Horse domestication and breed selection processes have profoundly influenced the development and transformation of human society and civilization over time. Therefore, their origin and history have always attracted much attention. In Italy, several local breeds have won prestigious awards thanks to their unique traits and socio-cultural peculiarities. Here, for the first time, we report the genetic variation of three loci of the male-specific region of the Y chromosome (MSY) of four local breeds and another one (Lipizzan, UNESCO) well-represented in the Italian Peninsula. The analysis also inc...
The Characteristics, Distribution, Function, and Origin of Alternative Lateral Horse Gaits. This article traces the characteristics, origin, distribution, and function of alternative lateral horse gaits, i.e., intermediate speed lateral-sequence gaits. Such alternative lateral gaits (running walk, rack, broken pace, hard pace, and broken trot) are prized by equestrians today for their comfort and have been found in select horse breeds for hundreds of years and even exhibited in fossil equid trackways. After exploring the evolution and development of alternative lateral gaits via fossil equid trackways, human art, and historical writings, the functional and genetic factors that led to...
Horses discriminate between human facial and vocal expressions of sadness and joy. Communication of emotions plays a key role in intraspecific social interactions and likely in interspecific interactions. Several studies have shown that animals perceive human joy and anger, but few studies have examined other human emotions, such as sadness. In this study, we conducted a cross-modal experiment, in which we showed 28 horses two soundless videos simultaneously, one showing a sad, and one a joyful human face. These were accompanied by either a sad or joyful voice. The number of horses whose first look to the video that was incongruent with the voice was longer than their first ...
Genetic structure and genome-wide association study of the traditional Kazakh horses. Horses are traditionally used in Kazakhstan as a source of food and as working and saddle animals as well. Here, for the first time, microarray-based medium-density single nucleotide polymorphism (SNP) genotyping of six traditionally defined types and breeds of indigenous Kazakh horses was conducted to reveal their genetic structure and find markers associated with animal size and weight. The results showed that the predefined separation between breeds and sampled populations was not supported by the molecular data. The lack of genetic variation between breeds and populations was revealed by t...
The serological detection of Bovine papillomavirus’s E5 oncoprotein antibodies in horses. Equine sarcoids (ES) are known globally as the most frequent skin tumour affecting horses. These tumours affect the horse's monetary value, they can affect the horse's welfare and can be difficult and expensive to treat. Bovine papillomavirus (BPV) is considered to be the aetiological agent of this tumour, as BPV 1, 2 and 13 have been detected in ES. This is the only known natural cross species infection by a papillomavirus. The BPV genome can be divided into two coding regions: The early region E which encodes the transforming proteins E5, E6 and E7 as well as the replication and transcriptio...
Genetic History of the Altai Breed Horses: From Ancient Times to Modernity. This study focuses on expanding knowledge about the genetic diversity of the Altai horse native to Siberia. While studying modern horses from two Altai regions, where horses were subjected to less crossbreeding, we tested the hypothesis, formulated on the basis of morphological data, that the Altai horse is represented by two populations (Eastern and Southern) and that the Mongolian horse has a greater genetic proximity to Eastern Altai horses. Bone samples of ancient horses from different cultures of Altai were investigated to clarify the genetic history of this horse breed. As a genetic mark...
Mitochondrial DNA sequencing illuminates genetic diversity and origin of Hunagrian Nonius horse breed and his relatives – Danubian horse and Serbian Nonius. From a historical perspective, horse breeding in Bulgaria has been very well developed since the time of the Thracians (early Bronze Age c. 3000 BCE). Archaeological discoveries from this era present us with an extremely rich type diversity, including wild and local primitive horses, the prototype of heavy draft horses, and fine riding horses.The objective of this study was to investigate the genetic structure of unexamined populations of three closely related horse breeds - the Danubian Nonius Hungarian Nonius and Serbian Nonius horses. A 608?bp long fragment of the mtDNA D-loop region was am...
Mitochondrial DNA sequencing of Kehilan and Hamdani horses from Saudi Arabia. The Arabian horse breed is well known for its purity and played a key role in the genetic improvement of other horses worldwide. The mitochondrial genome plays a vital role in maternal inheritance and it's helpful to evaluate its genetic diversity and conservation. It has higher mutation rates than nuclear DNA in vertebrates and therefore reveals phylogenetic relationships and haplotypes. In this study, the mitochondrial genome mutations in two Saudi horse strains, Kehilan and Hamdani demonstrated various changes in the gene and amino acid levels and included two other Saudi horses (Hadban and...
Detecting SNP markers discriminating horse breeds by deep learning. The assignment of an individual to the true population of origin using a low-panel of discriminant SNP markers is one of the most important applications of genomic data for practical use. The aim of this study was to evaluate the potential of different Artificial Neural Networks (ANNs) approaches consisting Deep Neural Networks (DNN), Garson and Olden methods for feature selection of informative SNP markers from high-throughput genotyping data, that would be able to trace the true breed of unknown samples. The total of 795 animals from 37 breeds, genotyped by using the Illumina SNP 50k Bead ch...
Genetic Diversity and Maternal Phylogenetic Relationships among Populations and Strains of Arabian Show Horses. Genetic diversity and phylogenetic relationships within the Arabian show horse populations are of particular interest to breeders worldwide. Using the complete mitochondrial DNA D-loop sequence (916 pb), this study aimed (i) to understand the genetic relationship between three populations, the Desert-Bred (DB), a subset of the Kingdom of Saudi Arabia (KSA), United Arab Emirates (UAE) and Bahrain (BAH), the Straight Egyptian (EG) and the Polish bloodline (PL), and (ii) to assess the accuracy of the traditional strain classification system based on maternal lines, as stated by the Bedouin cultur...
Occurrence of equine metabolic syndrome, clinical manifestations, and associated risk factors in Nigeria. Insulin dysregulation (ID) is central to the pathophysiology of equine metabolic syndrome (EMS), putting the horse at risk of laminitis. There is a paucity of information on the status of EMS in Nigeria. This study aimed to determine the occurrence of EMS, clinical manifestations, and associated risk factors in Nigeria. A cross-sectional study was carried out. Selected horses underwent an insulin 2-step response test to ascertain insulin dysregulation; a physical examination was carried out to diagnose laminitis and obesity. Risk factors were assessed using a questionnaire. The overall prevale...
Genetic diversity and signatures of selection in four indigenous horse breeds of Iran. Indigenous Iranian horse breeds were evolutionarily affected by natural and artificial selection in distinct phylogeographic clades, which shaped their genomes in several unique ways. The aims of this study were to evaluate the genetic diversity and genomewide selection signatures in four indigenous Iranian horse breeds. We evaluated 169 horses from Caspian (n = 21), Turkmen (n = 29), Kurdish (n = 67), and Persian Arabian (n = 52) populations, using genomewide genotyping data. The contemporary effective population sizes were 59, 98, 102, and 113 for Turkmen, Caspian, Persian Ar...
Circulating oxidative stress and acute phase protein levels in horses infested with ticks. Ticks have saliva rich in immunoregulatory molecules that interfere with the host's physiology in order to feed. This study aimed to evaluate the concentration of acute phase proteins and circulating oxidative stress in response to infestation by Amblyomma sculptum and Dermacentor nitens in two breed horses, Mangalarga Marchador and Breton Postier, to define resistance or susceptibility to ticks. Among the oxidative stress markers, we observed lower malondialdehyde and nitric oxide in horses with tick infestation, consequently not altering the antioxidant enzymes. Breton Postier with tick infe...