Athletic Performance In Horses Research Articles

Early-life gut bacterial community structure predicts disease risk and athletic performance in horses bred for racing

Gut bacterial communities have a profound influence on the health of humans and animals. Early-life gut microbial community structure influences the development of immunological competence and susceptibility to disease. For the Thoroughbred racehorse, the significance of early-life microbial colonisation events on subsequent health and athletic performance is unknown. Here we present data from a three-year cohort study of horses bred for racing designed to explore interactions between early-life gut bacterial community structure, health events in later life and athletic performance on the racetrack. Our data show that gut bacterial community structure in the first months of life predicts the risk of specific diseases and athletic performance up to three years old. Foals with lower faecal bacterial diversity at one month old had a significantly increased risk of respiratory disease in later life which was also associated with higher relative abundance of faecal Pseudomonadaceae. Surprisingly, athletic performance up to three years old, measured by three different metrics, was positively associated with higher faecal bacterial diversity at one month old and with the relative abundance of specific bacterial families. We also present data on the impact of antibiotic exposure of foals during the first month of life. This resulted in significantly lower faecal bacterial diversity at 28 days old, a significantly increased risk of respiratory disease in later life and a significant reduction in average prize money earnings, a proxy for athletic performance. Our study reveals associations between early-life bacterial community profiles and health events in later life and it provides evidence of the detrimental impact of antimicrobial treatment in the first month of life on health and performance outcomes in later life. For the first time, this study demonstrates a relationship between early-life gut bacterial communities and subsequent athletic performance that has implications for athletes of all species including humans.

Early‐life gut bacterial community structure predicts disease risk and athletic performance in horses bred for racing

Early‐life gut bacterial community structure predicts disease risk and athletic performance in horses bred for racing

Comparison of the fecal microbiota with high- and low performance race horses.

Exercise plays an important role in regulating energy homeostasis, which affects the diversity of the intestinal microbial community in humans and animals. To the best of the authors' knowledge, few studies have reported the associations between horse gut microbiota along with their predicted metabolic activities and the athletic ability of Jeju horses and Thoroughbreds living in Korea. This study was conducted to investigate the association between the gut microbiota and athletic performance in horses. This study sequenced the V3 and V4 hypervariable regions of the partial 16S rRNA genes obtained from racehorse fecal samples and compared the fecal microbiota between high- and low-performance Jeju horses and Thoroughbreds. Forty-nine fecal samples were divided into four groups: high-performance Jeju horses (HJ, n = 13), low-performance Jeju horses (LJ, n = 17), high-performance Thoroughbreds (HT, n = 9), and low-performance Thoroughbreds (LT, n = 10). The high-performance horse groups had a higher diversity of the bacterial community than the low-performance horse groups. Two common functional metabolic activities of the hindgut microbiota (i.e., tryptophan and succinate syntheses) were observed between the low-performance horse groups, indicating dysbiosis of gut microbiota and fatigue from exercise. On the other hand, high-performance horse groups showed enriched production of polyamines, butyrate, and vitamin K. The racing performance may be associated with the composition of the intestinal microbiota of Jeju horses and Thoroughbreds in Korea.

Assessing the cardiac valves conditions in athletic horses with poor performance.

Heart murmurs and valvular regurgitation are common in horses and often have no effect on their performance. However, when structural changes occur in the heart size, they can affect performance adversely. This study aimed to examine the correlation between cardiac valves disease and poor performance in athletic horses. A total of 300 athletic Thoroughbred and mix-breed horses including 164 mares and 136 stallions, with a history of poor performance, were selected. Horses with cardiac murmurs were identified and further cardiac examination including precise auscultation, base-apex electrocardiogram for possible dysrhythmias at rest and after exercise, echocardiographic and hematological tests were conducted in two stages. The first was at admission time and the second examination was done four to six months later to evaluate the outcome of the possible disorders. Respiratory system and musculoskeletal diseases were diagnosed respectively in 93 and 149 out of 300 examined horses and 36 horses showed heart murmur without any other complications. Echocardiography was performed in horses with heart murmur and 25 of them showed regurgitation of the cardiac valve. During the first examination, 7 horses were diagnosed with regurgitation and changes in the size of cardiac chambers, whereas this number increased to 25 during the second examination. There was no significant relationship between degree of murmur and severity of regurgitant jet in horses. The valvular regurgitation can affect the performance when causing changes in the size of the cardiac chambers which can consequently jeopardize the athletic future of the horse.

"Autologous Bone Marrow-Derived Mesenchymal Stem Cells for Tendon Repair in Horses: Experimental Study"

Tendon lesions are a major cause of lameness and reduced performance in athletic horses and may result in the early termination of the animal’s career with subsequent significant economic loss and animal welfare

La fisiología del ejercicio es una herramienta esencial en la evaluación de los equinos atletas: Revisión

The physiological and biochemical responses of the equine athlete, before, during and after physical exercise, are studied in the exercise physiology and, for this to start and muscle contraction occurs, for this it is necessary that the organism produces energy through the production of ATP, which occur in three processes, being alactic or lactic, the alactic process occurs through the metabolism of creatine phosphokinase (anaerobic form) and glucose through the Krebs cycle (aerobic form), whereas the lactic process occurs through the metabolism of lactate. During exercise, in an attempt to re-establish equine parameters, physiological changes occur. The physiology of exercise has been studying, through stress tests, performed on an ergometric treadmill or in the field, ways of obtaining parameters to evaluate the species. This study aimed to evaluate an essential tool that is the physiology of exercise on the physical conditioning of equine athletes, through parameters that observe the performance of these animals. For the methodology, a bibliographic survey of articles was made and directed to the physiology of equine exercise, in addition, necessary tools for the evaluation of equine athletes were addressed, being these neurological, cardiovascular, skeletal, and electrolytic responses. It is concluded that the use of tests for the evaluation of the athletic performance in horses performed by treadmill or in the field together with the physiological responses obtained by the action of exercise and training, is considered a valuable tool for equine sports medicine.

Identification and Functional Annotation of Genes Related to Horses' Performance: From GWAS to Post-GWAS.

Simple SummaryIt is assumed that the athletic performance of horses is influenced by a large number of genes; however, to date, not many genomic studies have been performed to identify candidate genes. In this study we performed a systematic review of genome-wide association studies followed by functional analyses aiming to identify the most candidate genes for horse performance. We were successful in identifying 669 candidate genes, from which we built biological process networks. Regulatory elements (transcription factors, TFs) of these genes were identified and used to build a gene–TF network. Genes and TFs presented in this study are suggested to play a role in the studied traits through biological processes related with exercise performance, for example, positive regulation of glucose metabolism, regulation of vascular endothelial growth factor production, skeletal system development, cellular response to fatty acids and cellular response to lipids. In general, this study may provide insights into the genetic architecture underlying horse performance in different breeds around the world.Integration of genomic data with gene network analysis can be a relevant strategy for unraveling genetic mechanisms. It can be used to explore shared biological processes between genes, as well as highlighting transcription factors (TFs) related to phenotypes of interest. Unlike other species, gene–TF network analyses have not yet been well applied to horse traits. We aimed to (1) identify candidate genes associated with horse performance via systematic review, and (2) build biological processes and gene–TF networks from the identified genes aiming to highlight the most candidate genes for horse performance. Our systematic review considered peer-reviewed articles using 20 combinations of keywords. Nine articles were selected and placed into groups for functional analysis via gene networks. A total of 669 candidate genes were identified. From that, gene networks of biological processes from each group were constructed, highlighting processes associated with horse performance (e.g., regulation of systemic arterial blood pressure by vasopressin and regulation of actin polymerization and depolymerization). Transcription factors associated with candidate genes were also identified. Based on their biological processes and evidence from the literature, we identified the main TFs related to horse performance traits, which allowed us to construct a gene–TF network highlighting TFs and the most candidate genes for horse performance.

Evaluation of two models of saddles on the back of Arabian horses through thermography

Dorsopathies are common causes of decreased performance in athletic horses of various modalities, and inadequate or poorly adjusted saddles can lead to the onset of injuries and low back pain. The present study, searching to find the most appropriate saddle, evaluated the pressure determined from the panels of two saddle models most commonly used in endurance Arab horse on the thoracolumbar region. For the study, six Arabian geldings were used, weighing 390 ± 4.2 and 2.1 ± age 8 years, conditioned to endurance races, and two saddle models, English and Western. The horses were submitted to the work riding on a sandy lane by the same experienced rider who weighed 76 kg. Thermography was performed before and after each exercise session. The obtained data were analyzed through Student’s paired t-test at 5% of significance. After exercise, there was a mean temperature difference between the contact areas of the right and left of the sweepers of two saddles compared, with the English saddle showing higher temperatures. Therefore, the Western saddle model, which has wider panels, despite not being a preferred model of endure riders, has proved to be more suitable for Arabian horse work.

Successful Anatomical Access for Surgical Removing of the Distal Fracture of Splint Bones in Thoroughbred Horses (Case Study)

Poor performance in athletic horses due to musculoskeletal affections is very common in Libya. Two mature thoroughbred horses suffering from poor performance and history of moderate degree forelimb lameness were admitted to the Aswany Private Equine clinic in Tripoli, Libya. The study is aiming for presenting a simple, time effective, cost effective surgical procedure to treat distal simple splint bone fracture in thoroughbred horses. Horses were examined thoroughly for the common muscle, hoof, and tendons affections. A progressed unilateral left forelimb swelling involving the lateral distal part of the fourth metacarpal bones was noticed. Three radiographs were taken to each horse including latero-medial, dorsolateral-palmaromedial, and palmarolateral-dorsomedial views to assess both splint bones. The radiographs showed that there is a complete fracture involving the distal extremity (button) of the fourth metacarpal bones. Surgical excisions of the fractured part of the splint bones have been decided to treat these horses. To precisely locate the site of the bone fragments, 1.5 mm stainless steel wires were placed over the distal part of splint prior to taking the radiographs. The surgical sites were aseptically prepared, and the horses were then sedated via intravenous injection of xylazine at a dose rate of 1 mg/kg body weight. The site of surgical incision was infiltrated with 2% lidocaine. The bone fragments were then removed after performing the surgical incision. The sharp end at the distal end of the proximal part of the splint bone was then smoothening with a scissor. The surgical incisions were then routinely closed and the post-operative care and radiographs were taken. The surgical incision made complete healing within two weeks. Both horses were followed up for up to three years post-operation, and they did well compared to what has been done in other studies. We concluded that the surgical technique used to treat the two horses with splint bone fracture enrolled in the current study is a simple and effective procedure.

Equine performance genes and the future of doping in horseracing.

A horse's success on the racetrack is determined by genetics, training and nutrition, and their translation into physical traits such as speed, endurance and muscle strength. Advances in genetic technologies are slowly explaining the roles of specific genes in equine performance, and offering new insights into the development of novel therapies for diseases and musculoskeletal injuries that cause early retirement of many racehorses. Gene therapy approaches may also soon provide new means to artificially enhance the physical performance of racehorses. Gene doping, the misuse of gene therapies for performance enhancement, is predicted to be the next phase of doping faced by horseracing. The risk of gene doping to human sports has been recognised for almost 15years, and the introduction of the first gene doping detection tests for doping control in human athletes is imminent. Gene doping is also a threat to horseracing, but there are currently no methods to detect it. Efficient and accurate detection methods need to be developed to deter those looking to use gene doping in horses and to maintain the integrity of the sport. Methods developed for human athletes could offer an avenue for detection in racehorses. Development of an equine equivalent test will first require identification of equine genes that will likely be targeted by gene doping attempts. This review focuses on genes that have been linked to athletic performance in horses and, therefore, could be targeted for genetic manipulation. The risks associated with gene doping and approaches to detect gene doping are also discussed. Copyright © 2017 John Wiley & Sons, Ltd.

Candidate genes for performance in horses, including monocarboxylate transporters

ABSTRACT: Some horse breeds are highly selected for athletic activities. The athletic potential of each animal can be measured by its performance in sports. High athletic performance depends on the animal capacity to produce energy through aerobic and anaerobic metabolic pathways, among other factors. Transmembrane proteins called monocarboxylate transporters, mainly the isoform 1 (MCT1) and its ancillary protein CD147, can help the organism to adapt to physiological stress caused by physical exercise, transporting lactate and H+ ions. Horse breeds are selected for different purposes so we might expect differences in the amount of those proteins and in the genotypic frequencies for genes that play a significant role in the performance of the animals. The study of MCT1 and CD147 gene polymorphisms, which can affect the formation of the proteins and transport of lactate and H+, can provide enough information to be used for selection of athletic horses increasingly resistant to intense exercise. Two other candidate genes, the PDK4 and DMRT3, have been associated with athletic potential and indicated as possible markers for performance in horses. The oxidation of fatty acids is highly effective in generating ATP and is controlled by the expression of PDK4 (pyruvate dehydrogenase kinase, isozyme 4) in skeletal muscle during and after exercise. The doublesex and mab-3 related transcription factor 3 (DMRT3) gene encodes an important transcription factor in the setting of spinal cord circuits controlling movement in vertebrates and may be associated with gait performance in horses. This review describes how the monocarboxylate transporters work during physical exercise in athletic horses and the influence of polymorphisms in candidate genes for athletic performance in horses.

Association between exercise-induced pulmonary hemorrhage and inflammatory airway disease in polo ponies.

ABSTRACTThe respiratory system is essential for health and high athletic performance in horses. Respiratory diseases have been recognized as having a major impact on training equine animals and are commonly cited as the second most common cause of wasted training time. Inflammatory airway disease (IAD) is an important cause of poor performance in young racehorses. Exercise-induced pulmonary hemorrhage (EIPH) is considered a major issue for the equine industry because of its high prevalence and association with reduced athletic performance. In Brazil, polo is a growing equestrian sport, but studies on it are still scarce. The aim of this study was to evaluate the occurrence of EIPH, the association between EIPH and IAD, and EIPH influence on the tracheal cytological profile of polo ponies. Thirty-seven horses regularly used for polo were included in this study. Endoscopic examination was performed every 30 to 90 min after practice, and tracheal lavage was performed after 18 to 24 hr. Sixteen animals (43.2%) presented a score of 0 for mucus in endoscopy; twelve animals (32.4%) presented a score for 1 and nine animals (24.3%) presented score 2 of mucus. IAD was characterized by tracheal cytology in 12 animals (32.4%). The occurrence of EIPH in this study was 29.7% (11/37). No significant difference was found in the cell types in tracheal cytology when EIPH-positive and EIPH-negative horses were compared. Polo ponies are affected by IAD and EIPH in relevant proportions, but there was no association between EIPH and tracheal cytological profile.

Mitral Valve Regurgitation in two Thoroughbred Stallions

Abstract Mitral valve (MV) disease is the most important valvular condition affecting athletic performance in horses. Twenty and 22 years old Thoroughbred Stallions used for breeding had suffered from increased respiratory and heart rate, poor performance and incomplete ejaculate release during covering, since three months ago. Cardiac examination projected irregular cardiac rhythm after a halt and an early-mid-systolic murmur. Mitral regurgitation (MR) and valvular changes were visible on echocardiography. Also volume overload of the Left Atrium (LA) and Left Ventricle (LV) were observed. Color Flow Doppler echocardiography confirmed moderate mitral valve regurgitation. A band-like fibrous and nodular degeneration of the left coronary leaflet was present. There was minimal secondary left ventricular remodeling of the apex of the left ventricle due to chronic volume overload. The therapeutic attempts included Quinapril and Furosemide. In these cases, normally no structural effect could be achieved, but clinical improvement and successful covering sessions were obtained, and when the therapy was terminated, clinical problems reappeared. In conclusion, in horses with MR, early diagnosis and appropriate therapy with Quinapril promises a reasonable performance.

Diagnostic value of computed tomography, radiography and ultrasonography in metacarpophalangeal joint disorders in horses

In modern society the work and athletic performance of horses has led to a very important animal production sector in which Brazil possesses the third largest horse stock. Among all equine lesions described, metacarpophalangeal (fetlock) joint lesions are considered one of the main causes of lameness. Consequently, there is a need to improve the understanding and diagnosis of these injuries. The most efficient imaging diagnostic methods for the fetlock region are computed tomography, radiography and ultrasound. Imaging studies of the anatomical structures involving this joint are extremely important to obtain a more precise diagnose. The present study was performed in order to evaluate the capacity of different imaging diagnostic modalities to detect a variety of lesions in different fetlock structures. Twenty horses (Equus caballus) used for horsemanship activities were referred to the Department of Animal Reproduction and Veterinary Radiology of São Paulo State University, Botucatu campus, with clinical signs of metacarpophalangeal joint injuries. Horses were submitted to radiographic and ultrasonographic exam and computed tomography scan. Image analysis revealed a significant capacity of these methods to characterize lesions in this region. However, computed tomography provided broader and better evaluation of lesions in bones and adjacent structures, because it allows the analysis to be performed on three-dimensional projections, with attenuation coefficients (window selections) and tissue density measurement through Hounsfield Units (HU).

Comparison of Sequence Variants in the PDK4 and COX4I2 Genes Between Racing and Cutting Lines of Quarter Horses and Associations With the Speed Index

Different selection objectives within the Quarter Horse breed led to the formation of groups with distinct skills, including the racing and cutting lines. With a smaller population size in Brazil, but of great economic representativeness, the racing line is characterized by animals that can reach high speeds over short distances and within a short period of time. The cutting line is destined for functional tests, exploring skills such as agility and obedience. Although the athletic performance of horses is likely to be influenced by a large number of genes, few genetic variants have so far been related to this trait and this was done exclusively in Thoroughbreds, including the g.38973231G>A single-nucleotide polymorphism in the PDK4 gene and the g.22684390C>T single-nucleotide polymorphism in the COX4I2 gene. The results of the present study demonstrate the presence of polymorphic PDK4 and COX4I2 genes in Quarter Horses. The analysis of 296 racing animals and 68 cutting animals revealed significant differences in allele and genotype frequencies between the two lines. The same was not observed when these frequencies were compared between extreme racing performance phenotypes. There were also no significant associations between alleles of the two polymorphisms and the speed index. These results suggest that the alleles of the PDK4 and COX4I2 genes, which are related to better racecourse performance in Thoroughbreds, are probably associated with beneficial adaptations in aerobic metabolism and therefore play secondary roles in sprint racing performance in Quarter Horses, which is mainly anaerobic.

Heart Rate, Net Cost of Transport, and Metabolic Power in Horse Subjected to Different Physical Exercises

Considering that workload can also be expressed in terms of estimated net transport cost (COT), the metabolic energy needed to transport unit mass of animal unit distance, the aim of our study was to describe the heart rate (HR), COT, and the total metabolic power requirement per kilogram (P) during different exercises (aerobic, anaerobic, and aerobic–anaerobic exercises). On the basis of their attitude, 25 horses, divided into five equal groups, traveled a distance of 6,000 m, walking at 100 m/min in a horse walker (group A); performed 20-minute treadmill walk at 130 m/min, average speed up gradient of 5% (group B); performed a 700-m-long show jumping course with 13 fences (group C); traveled a distance of 2,100 m galloping at a speed of 700 m/min (group D); and traveled a distance of 2,000 m trotting at a speed of 660 m/min (group E). On each horse, HR was continuously recorded by means of an equine HR monitor. COT was calculated with the following formula: (HR − 35) kg−1 m−1 103; P was calculated applying the formula: (HR − 35) min−1 kg−1. COT and P values, estimated from the mean HR, measured continuously during each experimental condition showed no linear relationship with HR and speed. The use of combined weight of horse and tack (group C and D) and horse, tack, and sulky (group E) statistically changed the results of formula application. COT and P change in different exercises and provide additional information about performance in athletic horses.

UPPER AIRWAY EVALUATIONS OF THOROUGHBRED RACEHORSES IN A PRIVATE CLINIC IN CURITIBA, BRAZIL – RESTING ENDOSCOPIC FINDINGS IN 587 HORSES

Obstructive upper airway diseases are an important cause of poor performance in athletic horses. The present study aimed to determine the prevalence of common URT abnormalities (pharyngeal lymphoid hyperplasia - PLH, dorsal displacement of the soft palate - DDSP and recurrent laryngeal neuropathy - RLN) in a population of Thoroughbred racehorses in training submitted to resting endoscopy in a private clinic in Curitiba, Paraná, Brazil. 587 URT resting endoscopies, 385 2-year-old and 202 3-year-old-plus horses, were performed during the period of the study and the clinical records of all the examinations were reviewed and analysed. 340 (57.9 %) horses were evaluated for routine athletic follow up, 15 (2.6%) were pre-purchase examinations, 83 (14.1%) were examined as an investigation for cough, 58 (9.9%) horses had poor performance, 48 (8.2%) had abnormal respiratory noise, 35 (6.0%) had epistaxis and 8 (1.4%) had nasal discharge. Pharyngitis (Grades III, IV PLH) was diagnosed in 198 (33.7%) horses and was more prevalent in the 2-year-old group than in the older horses (40.5% vs. 20.8%, P<0.05). DDSP was identified in 185 (31.5%) horses, Grade III RLN in 13 (2.2%) and Grade IV was seen in 21 (3.6%) horses. The present study gives a prevalence of upper airway abnormalities in resting endoscopic evaluation in a racehorse population in Brazil.

The use of streptolysin O (SLO) as an adjunct therapy for Rhodococcus equi pneumonia in foals

Rhodococcus equi is a soil borne bacterium that causes severe morbidity and death in young foals. The economic costs of the disease include loss of life, treatment expenses, veterinary monitoring expenses and, perhaps most importantly, potential reduction in future athletic performance in horses that suffer severe lung abscessations caused by R. equi. Current standard of care for pneumonia caused by R. equi is treatment with a macrolide antimicrobial and rifampicin. However, the hallmark of pneumonia caused by R. equi is severe formation of pyogranulomas and a walling off effect that can prevent systemic antibiotics from reaching antimicrobial concentrations in lung tissues. It is hypothesized that streptolysin O (SLO) used as an adjunct therapy with antibiotics will reduce the duration and severity of disease caused by R. equi pneumonia compared to antibiotic therapy alone. Addition of SLO to the antibiotic enhanced clinical responses compared to the other groups, including the antibiotic alone group. Of particular significance were lower bacterial counts in the lungs and longer survival time in those foals treated with SLO and antibiotics.

Candidate genes for physical performance in the horse

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 candidate genes for equine performance are presented that have polymorphisms associated with human elite athletic performance and may have impact on athletic performance in horses. A significant accumulation of candidate genes was found on horse chromosomes 4 and 12. Genes involved in pathways for focal adhesion, regulation of actin cytoskeleton, neuroactive ligand-receptor interaction, and calcium signalling were over-represented. Genome-wide association studies for athletic performance in horses may benefit from the strong conserved synteny of the chromosomal arrangement of genes in humans and horses.

The impact of long-term clenbuterol on athletic performance in horses

The impact of long-term clenbuterol on athletic performance in horses