Journal of Equine Veterinary Science最新文献

{"title":"Effects of sample storage time and temperature on equine complete blood counts","authors":"MM Friend,&nbsp;EM McGaffigan,&nbsp;SM Hall,&nbsp;WB Staniar,&nbsp;DN Smarsh","doi":"10.1016/j.jevs.2026.105782","DOIUrl":"10.1016/j.jevs.2026.105782","url":null,"abstract":"<div><h3>Background</h3><div>Equine blood samples are often collected in uncontrolled, distant environments and stored for later analysis.</div></div><div><h3>Aims</h3><div>This study aimed to determine how sample storage methods influence complete blood count (CBC) parameters, hypothesizing that temperature and time elapsed from collection to analysis would affect CBC parameters.</div></div><div><h3>Methods</h3><div>Blood samples were collected from 10 healthy Quarter Horse mares (age: 13 ± 4.5 years old) and stored in EDTA tubes at room temperature (22°C), above ice (8°C), refrigerated (4°C), or in contact with ice (2°C). The IDEXX ProcyteDx was used to obtain CBCs at 3, 6, 12, 24, 48, and 72 hours after collection. Data were analyzed using the Kruskal-Wallis test with Dunn’s post hoc analysis and Benjamini-Hochberg correction. Significance was set to <em>P</em> ≤ 0.05.</div></div><div><h3>Results</h3><div>A reduction of monocytes and elevation of basophils was seen as early as 48 hours at 2°C, 4°C, and 8°C and occurred to a greater extent at 22°C, likely due to a greater degree of cellular degradation. Changes to red blood cell parameters occurred as early as 48 hours after collection at 4°C and 8°C and were more exaggerated at 22°C. Storage at 2°C resulted in earlier differences in red blood cell parameters. In contrast with previous studies, platelet counts were increased with time in all cooled storage methods, exhibiting a progressive temperature-dependent response as early as 24 hours.</div></div><div><h3>Conclusion</h3><div>It appears equine blood samples are most stable when stored at 4°C or 8°C and run within 48 hours when using the IDEXX Procyte Dx.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"158 ","pages":"Article 105782"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146003563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Congenital malformations of the thoracic vertebral column in a mature competition pony","authors":"Brenda Hoogelander ,&nbsp;Thibault Frippiat ,&nbsp;Hendrik Jan Bergman ,&nbsp;Katrien Vanderperren ,&nbsp;Elisabeth C.S. van Veggel","doi":"10.1016/j.jevs.2026.105800","DOIUrl":"10.1016/j.jevs.2026.105800","url":null,"abstract":"<div><div>Thoracolumbar congenital abnormalities are considered rare in mature, performing horses. This case report describes a 14-year-old Welsh pony presented with marked epaxial muscle atrophy, mid-thoracic spinal pain, and stiffness, most pronounced during canter. The thoracic spine exhibited scoliosis, centered at T9–T10, and kyphosis. Radiography and postmortem computed tomography revealed complex congenital malformations of the thoracic vertebral column, including abnormal morphology of the T10–T12 vertebral bodies, partial vertebral fusion, a malformed spinous process, a malformed rib with associated costovertebral and costotransverse joints, and degenerative changes affecting multiple costovertebral and costotransverse joints. Given the combination of persistent ridden behavioral manifestations, safety concerns for a young rider, financial limitations, and the extent of the anatomical abnormalities, euthanasia was elected by the owner. This report highlights the importance of considering congenital thoracic vertebral anomalies as a potential contributor to chronic thoracolumbar pain in adult horses, even in the absence of neurological deficits.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"158 ","pages":"Article 105800"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146131980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spirulina supplementation regulates inflammation and supports cartilage health in adult sedentary horses following moderate-intensity exercise","authors":"N.G. Golestani ,&nbsp;M.P. Paton ,&nbsp;B.R. Ross ,&nbsp;A.W. Wildish ,&nbsp;M.S.D. Duarte ,&nbsp;C.A.W. Williams ,&nbsp;W.P. Pearson","doi":"10.1016/j.jevs.2026.105804","DOIUrl":"10.1016/j.jevs.2026.105804","url":null,"abstract":"<div><h3>Background</h3><div>Horses experience rapid physiological, inflammatory, and oxidative responses during exercise. Spirulina, a nutrient-dense microalga with antioxidant and anti-inflammatory properties, may help modulate these responses and support recovery.</div></div><div><h3>Objectives</h3><div>This study evaluated the effects of 30-day dietary Spirulina supplementation on physiological, inflammatory, and oxidative stress responses to moderate-intensity exercise in sedentary horses. We hypothesized that 30-day Spirulina supplementation would modulate hematologic and inflammatory responses and support recovery from moderate-intensity exercise in sedentary horses.</div></div><div><h3>Methods</h3><div>Sixteen healthy, sedentary horses (11.4 ± 1.5 years; 528 ± 16 kg) were randomly assigned to Spirulina (SP, 30 g/d; <em>n</em> = 8) or control (C; <em>n</em> = 8) for 30 days. All horses completed a 30-min standardized treadmill exercise test (SET) on day 0 (pre-supplementation) and day 30 (post-supplementation). Jugular blood was collected at baseline, and 10 min, 1 h, 8 h, and 24 h post-SET; synovial fluid was collected from the intercarpal joint at baseline, and 8 h, 24 h, and 120 h post-SET. Samples were analyzed for CBC, biochemistry, nitric oxide (NO), resolvin D1 (RvD1), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), glycosaminoglycans (GAG), and chondroitin sulfate epitope 846 (CS846). Two-way ANOVA assessed treatment × time within each day, and day × time within each treatment.</div></div><div><h3>Results</h3><div>On day 0, groups did not differ. On day 30, SP horses had higher RBC and hemoglobin (<em>p</em> = 0.02, 0.03) and a greater neutrophil:lymphocyte ratio (<em>p</em> = 0.03). Plasma RvD1 was increased in SP horses at 10 min, 1 h, and 8 h post-SET (p ≤ 0.04) and in synovial fluid at 8–120 h (p ≤ 0.03). Plasma NO was lower in SP at 1 h (<em>p</em> = 0.01), whereas synovial fluid NO was higher at 24 h (<em>p</em> = 0.04). No effects were observed for SOD, GSH-Px, CS846, or GAG.</div></div><div><h3>Conclusions</h3><div>Spirulina supplementation was associated with modest changes in selected hematologic and inflammatory markers, particularly RvD1 and NO, but did not influence antioxidant enzymes or cartilage biomarkers. These findings indicate limited effects under moderate exercise conditions in sedentary horses.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"158 ","pages":"Article 105804"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146149985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"miRNAS and target genes are regulated post-training in quarter horse athletes","authors":"Thiago Maués Amaral ,&nbsp;Priscilla do Carmo de Azevedo Ramos ,&nbsp;Roberta de Araújo Silva ,&nbsp;Murilo Moura Ferreira ,&nbsp;Ednaldo da Silva Filho","doi":"10.1016/j.jevs.2026.105787","DOIUrl":"10.1016/j.jevs.2026.105787","url":null,"abstract":"<div><h3>Introduction</h3><div>In the context of Brazilian equestrian sports, the Quarter Horse (QH) breed has the third largest population of registered horses and stands out for its numerous abilities in various disciplines. Studies on equine health and athletic performance parameters are scarce, especially involving molecular markers.</div></div><div><h3>Objective/methods</h3><div>This study aimed to investigate the differential expression of microRNAs and target genes involved in metabolic pathways of exercise and to assess hematological and clinical changes in 10 horses (<em>Equus caballus</em> Linnaeus) of the QH breed under different physiological conditions. Horses of both sexes, aged 6 years, weighing between 400 and 513 kg (442,3 kg Mean), with the same housing, feeding, and training management throughout the experiment. The horses were subjected to a race with obstacle deviation.</div></div><div><h3>Results</h3><div>The results of clinical, hematological, and molecular parameters showed significance (<em>p</em> &lt; 0.05) after exercise. These bioindicators demonstrate that equine physiology is modulated after training, with an increase in oxygen transport, oxygen metabolism for energy conversion, and post-training recovery induced by the inflammatory response to aerobic exercise.</div></div><div><h3>Conclusions</h3><div>The revealed data should be considered important parameters for animal health management and for assessing the physiological performance of horses during training, especially for athletic QH horses raised in the Amazon region.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"158 ","pages":"Article 105787"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146029793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Translational human and equine regenerative medicine in musculoskeletal conditions","authors":"L.M. Bosman ,&nbsp;M.G. Logan ,&nbsp;A. Miszewski ,&nbsp;M.S. Pepper","doi":"10.1016/j.jevs.2026.105798","DOIUrl":"10.1016/j.jevs.2026.105798","url":null,"abstract":"<div><div>Translational regenerative medicine, integrating human and veterinary approaches within the “One Health” framework, increasingly uses horses as models for human musculoskeletal conditions due to shared anatomical and functional features. Osteoarthritis and tendon disorders affect both species, often resulting from high-impact or repetitive strain activities. Regenerative medicine offers therapeutic opportunities by promoting tissue repair and modulating inflammation. Cellular orthobiologics such as mesenchymal stromal/stem cells (MSCs) show promise for treating osteoarthritis and tendon injuries in humans and horses, while non-cellular orthobiologics—including platelet-rich plasma, interleukin-1 receptor antagonist protein, and alpha-2 macroglobulin—provide growth factors and anti-inflammatory molecules that support tissue regeneration. However, challenges remain, including variable product manufacture, inconsistent MSC isolation and characterization protocols (particularly in equine applications), and regulatory or public scepticism toward these therapies. Standardized production methods and improved clinical integration are needed. Combinatory use of cellular and non-cellular orthobiologics offers strong translational potential to improve musculoskeletal repair across species.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"158 ","pages":"Article 105798"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146113290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infertility in an American Quarter Horse mare with cervical duplication","authors":"D. Cortes ,&nbsp;M. Mendoza ,&nbsp;T. Raudsepp ,&nbsp;M. Ferrer","doi":"10.1016/j.jevs.2026.105785","DOIUrl":"10.1016/j.jevs.2026.105785","url":null,"abstract":"<div><div>Cervical duplication is a disorder of sexual development (DSD) that may be present in the absence of chromosomal aberrations. It is a rare cause of infertility in mares and is attributed to the failure of the Müllerian ducts to fuse properly, leading to the persistence of the median walls along the whole length of the cervix. This case report involves a 13-year-old American Quarter Horse mare with cervical duplication. Prior to this diagnostic, the mare was bred multiple times, but pregnancy was not achieved. The mare presented for a breeding soundness evaluation. During the examination an aberrant cervical conformation was palpated and further investigated. Cytogenetic analysis and a PCR for the Y-linked <em>SRY</em> gene and the X-linked androgen receptor gene was performed. A normal 64,XX, <em>SRY</em>-negative karyotype was determined. Infertility was associated with cervical abnormality, affecting in some degree uterine clearance causing accumulation of fluid seen on ultrasound.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"158 ","pages":"Article 105785"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146018814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enrofloxacin induces mild and transient vascular alterations following regional limb perfusion in horses","authors":"T.C. Valente ,&nbsp;R.P. Mendes ,&nbsp;E.L. Miguel ,&nbsp;L.A. Rafael ,&nbsp;G.S.N. Ribeiro ,&nbsp;A.F. Souza ,&nbsp;J.H. Fonteque","doi":"10.1016/j.jevs.2026.105777","DOIUrl":"10.1016/j.jevs.2026.105777","url":null,"abstract":"<div><h3>Background</h3><div>Regional intravenous limb perfusion (RILP) is widely used in equine practice for achieving high local antimicrobial concentrations while minimizing systemic exposure. However, certain drugs, including enrofloxacin, have been associated with vascular irritation and thrombosis, and their thrombogenic potential remains poorly characterized.</div></div><div><h3>Objectives</h3><div>This study aimed to evaluate the thrombogenic potential of enrofloxacin administered via RILP in the cephalic vein of clinically healthy horses.</div></div><div><h3>Methods</h3><div>Ten adult horses underwent RILP in both forelimbs: the right limb received 10 % enrofloxacin (1.5 mg/kg) diluted in 0.9 % NaCl to a total volume of 20 mL, while the left limb served as control (0.9 % NaCl, 20 mL). Clinical, thermographic, and ultrasonographic assessments were performed at baseline, immediately after tourniquet removal, and 24 and 48 hours post-RILP. Statistical comparisons were made between treatments and time points (<em>p</em> &lt; 0.05).</div></div><div><h3>Results</h3><div>No alterations in vital parameters were observed. No temperature differences occurred between limbs, although transient bilateral increases were detected immediately after tourniquet removal. Ultrasonography revealed temporary reductions in venous lumen diameter, returning to baseline within 24 hours in both groups. In the treated group, venous wall thickening was detected in six horses, and one developed mild thrombophlebitis. All lessons were resolved within 48 hours.</div></div><div><h3>Conclusions</h3><div>A single administration of enrofloxacin via RILP in the cephalic vein induced only mild and transient vascular changes, suggesting a low thrombogenic potential in healthy adult horses.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"158 ","pages":"Article 105777"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145933657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two cases of primary hepatic neoplasia in young horses: Diagnostic challenges and clinical implications","authors":"Natalia Siwinska ,&nbsp;Rafal Ciaputa ,&nbsp;Dorota Dlugopolska ,&nbsp;Marzena Paszkowska ,&nbsp;Wolfram Haider ,&nbsp;Kathrin Schwegler","doi":"10.1016/j.jevs.2026.105783","DOIUrl":"10.1016/j.jevs.2026.105783","url":null,"abstract":"<div><div>Primary hepatic neoplasms are rare in horses and often have a poor prognosis due to non-specific clinical signs and delayed diagnosis. This report describes two cases of primary hepatic neoplasia in young horses. The first case was a yearling Hanoverian filly presenting with non-specific clinical signs, including poor weight gain and inappetence, ultimately diagnosed with hepatoblastoma based on ultrasonographic findings and histopathological examination. The second case was a three-year-old Polish Sport Horse stallion that died suddenly, with post-mortem examination revealing advanced cholangiocarcinoma, a malignant bile duct neoplasm. These cases highlighted the diagnostic challenges of hepatic neoplasms in horses due to non-specific early clinical signs. Hepatic neoplasms should be considered in the differential diagnosis in horses with unexplained weight loss and abnormal hepatic function, regardless of age.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"158 ","pages":"Article 105783"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145998344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Left and right-side echocardiographic measurement of pulmonary artery stiffness in thoroughbred racehorses","authors":"C. Bozzola ,&nbsp;L. Stucchi ,&nbsp;G. Sala ,&nbsp;L. Schinardi ,&nbsp;G. Stancari ,&nbsp;E. Zucca","doi":"10.1016/j.jevs.2026.105784","DOIUrl":"10.1016/j.jevs.2026.105784","url":null,"abstract":"<div><h3>Background</h3><div>Pulmonary Artery Stiffness (PAS) is a non-invasive echocardiographic index of pulmonary artery elasticity. In horses, PAS has been measured only from the right parasternal short-axis view, while the influence of alternative imaging windows remains unknown.</div></div><div><h3>Aims/objectives</h3><div>To assess the repeatability and reproducibility of Acceleration Time (AT), Maximal Frequency Shift (MFS), and PAS measurements from the left parasternal angled view of the right ventricular inflow/outflow, and to compare these parameters with those obtained from the right parasternal short-axis view in Thoroughbred racehorses.</div></div><div><h3>Methods</h3><div>Forty Thoroughbreds underwent pulsed-wave Doppler echocardiography from both right and left parasternal views. Measurements included AT, MFS, and PAS (MFS/AT). The intra-class correlation coefficient (ICC) and the coefficients of variation (CV) were used to assess intra-operator repeatability and inter-operator (three operators) reproducibility in 40 horses, day-to-day (two different days) repeatability in 5 horses, and inter-operator (two operators) reproducibility for image acquisition in 10 horses. The Wilcoxon signed-rank test was used to compare left and right parasternal measurements in 40 horses.</div></div><div><h3>Results</h3><div>Intra-operator agreement was excellent for all parameters (AT: ICC=0.94; MFS: ICC=0.95; PAS: ICC=0.97). Inter-operator agreement ranged from moderate to excellent (AT: ICC=0.63–0.87; MFS: ICC=0.96–0.99; PAS: ICC=0.83–0.96). Day-to-day agreement was good for AT (ICC=0.80) and MFS (ICC=0.71), and excellent for PAS (ICC=0.98). Inter-observer agreement for image acquisition ranged from good to excellent (AT: ICC=0.97, MFS: ICC=0.86, PAS: ICC=0.94). Compared to the right view, the left parasternal view showed lower AT (110 vs. 151 ms), higher MFS (2.6 vs. 2.27 kHz), and higher PAS (23.8 vs. 15.6 kHz/s) (all <em>p</em>&lt;0.001).</div></div><div><h3>Conclusion</h3><div>PAS can be consistently measured from the left parasternal angled view in Thoroughbred racehorses. PAS was higher when measured from the left parasternal window, possibly due to a better alignment of the Doppler beam with the pulmonary artery flow.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"158 ","pages":"Article 105784"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146018806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metabolomics of stallion seminal plasma: Identification of potential fertility biomarkers based on differences between high and low pregnancy stallions","authors":"V.L.C. Bueno ,&nbsp;H.B.A. Bastos ,&nbsp;L.A.M. Centeno ,&nbsp;F. Schmitt ,&nbsp;G. Larentis ,&nbsp;R.C. Mattos ,&nbsp;S. Fiala-Rechsteiner","doi":"10.1016/j.jevs.2026.105780","DOIUrl":"10.1016/j.jevs.2026.105780","url":null,"abstract":"<div><h3>Background</h3><div>The seminal plasma (SP), a fluid originating from the testes, epididymis, and accessory sex glands, represents 98 % of the volume of stallion ejaculate. Metabolomic analysis enables the identification of final products of metabolic pathways, providing insights into reproductive physiology.</div></div><div><h3>Objective</h3><div>This study aimed to investigate the metabolomic profile of stallion seminal plasma and to investigate metabolic differences between stallions with high and low pregnancy rates, in order to identify potential biomarkers associated with fertility.</div></div><div><h3>Methods</h3><div>Twenty-four Criollo stallions, were sampled for molecular biology once during the breeding season.</div></div><div><h3>Results</h3><div>Pregnancy rates at day 16 post-insemination ranged from 20.2 % to 95.6 %, forming two groups: High Pregnancy (HP; ≥60 %) and Low Pregnancy (LP; ≤50 %). Semen was evaluated for concentration, kinetics, morphology, and membrane integrity. Metabolic profiling using UHPLC-QTOF-MS identified 18 metabolites, including acetyl carnitine, carnitine, isoleucine, methylbutanoyl carnitine, ornithine, phenylalanine, tryptophan, taurine, palmitate, lactate, phosphate, oleate, stearate, citrate, fructose, hippurate, 1,3-dioxan-5-ol, and melatonin. Oleate showed higher abundance in LP stallions (<em>P</em> &lt; 0.05), whereas taurine and phosphate were enriched in HP stallions (<em>P</em> &lt; 0.05). Pearson correlation analysis revealed 13 metabolites significantly associated with reproductive outcomes, with phosphate and 1,3-dioxan-5-ol emerging as the most relevant. Phosphate, in particular, was highlighted as a potential fertility biomarker due to its essential role in sperm energy metabolism via pyrophosphate breakdown.</div></div><div><h3>Conclusion</h3><div>These findings elucidate molecular mechanisms underlying subfertility and support the identification of biomarkers for fertility prediction, offering potential applications in reproductive management and optimization strategies for stallions.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"158 ","pages":"Article 105780"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145933606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}