Journal of Equine Veterinary Science最新文献

{"title":"Pedigree tracing to determine coat color phenotype found within the Mountain Pleasure Horse Breed","authors":"J. Culwell ,&nbsp;M.C. Nicodemus ,&nbsp;E. North ,&nbsp;A. Irons ,&nbsp;M. Vandiver ,&nbsp;T. Williams","doi":"10.1016/j.jevs.2025.105514","DOIUrl":"10.1016/j.jevs.2025.105514","url":null,"abstract":"<div><div>The Mountain Pleasure Horse (MPH) is classified as “threatened,” with only 2,670 living purebred MPHs. To expand numbers, the registration books for MPH Association (MPHA) were opened in 2009; however, the books were recently closed due to concerns of potential loss of breed phenotypic characteristics. Although MPHA registration does not require a specific coat color, the palomino color is a characteristic of the foundation sires, setting the breed apart from the chocolate color of the Rocky Mountain Horse. As such, to determine whether there is a predominant breed coat color phenotype, the objective of this study was to use pedigree tracing to identify the phenotypic coat color assignments making up the MPHA. Using the MPHA database, a total of 1,410 pedigrees of purebred registered horses were sampled (53% of all living purebred MPHs). For purebred designation, genealogy must show 100% MPH bloodlines for 2 generations along with either DNA testing or blood-typing to prove parentage. Pedigrees used were those with complete records, meaning an uninterrupted generational record of the horse's ancestors and associated coat color assignments going to the earliest existing recorded relative. Coat color assignments were documented for each pedigree sampled with percentages determined for the 11 coat color assignments of MPHA. The reported phenotypes were consistent with the following 4 dilution alleles: cream, champagne, silver, and dun. Coat color assignments within 21.3% of the sampled horses were reflective of the cream dilution allele, including 16.4% of sampled horses designated as palomino (Table 1). Coat color assignment for 16.9% of the sampled horses was chocolate, reflective of the silver dilution allele. The most common coat color assignment was chestnut. Interestingly, for those reporting phenotype consistent of the roan allele, 1.8% of the sampled horses were designated as a red roan, thus having a chestnut base coat, with the remainder designated as blue roan (1.2%) or only assigned as roan (0.6%). In closing, the sampled pedigrees do not reflect that MPHA coat color assignments are predominantly palomino; however, responsible breeding practices could facilitate a larger population of purebred MPHs with the palomino coat color.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105514"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948023","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":"Effects of intra-articular corticosteroid administration on synovial biomarkers of inflammation, pain, and cartilage metabolism in young horses undergoing exercise","authors":"C.R. Gualandri ,&nbsp;J.L. Leatherwood ,&nbsp;A.S. Reiter ,&nbsp;L.R. Pavel ,&nbsp;C.E. Arnold ,&nbsp;K.G. Glass ,&nbsp;B.L. Paris ,&nbsp;M.M. Carter ,&nbsp;G.E. Moore ,&nbsp;P.K. Linne ,&nbsp;R.E. Martinez ,&nbsp;A.N. Bradbery","doi":"10.1016/j.jevs.2025.105485","DOIUrl":"10.1016/j.jevs.2025.105485","url":null,"abstract":"<div><div>Intra-articular corticosteroids (IAC) are administered to resolve joint inflammation; however, knowledge of the biological impacts of IAC in young, healthy horses is limited, and there are concerns that IAC are masking the root cause of pain and inflammation. Therefore, the objective was to determine the impacts of IAC administration on synovial fluid biomarkers of inflammation, pain, and cartilage metabolism. It was hypothesized that synovial inflammation, pain, and cartilage metabolism would decrease in response to IAC administration in young horses over a 56-d trial. Twenty-four Quarter Horses were stratified by age (825 ± 21 d), BW (409 ± 6 kg), and sex (12 mares, 12 geldings) and underwent a progressive workload (5 d/wk, 45 min/d) using a freestall exerciser. One radiocarpal joint was randomly assigned to one of 3 intra-articular treatments consisting of control (CON; n = 8), 6 mg (CORT6; n = 8), or 12 mg (CORT12; n = 8) of triamcinolone acetonide (TA). Synovial fluid was collected via arthrocentesis before IAC administration (d 0) and again on d 7, 14, 28, and 56 post-injection. Samples were analyzed for prostaglandin E₂ (PGE₂), substance P (SP), procollagen II c-propeptide (CPII), and collagen type II cleavage (C2C) by commercial ELISA. Data were analyzed using PROC MIXED of SAS, where non-normal data were log-transformed. The fixed effects were treatment, time, sex, and their interaction; however, sex was removed when nonsignificant. Significance was considered where <em>P</em> ≤ 0.05 and a trend where 0.05 &lt; <em>P</em> ≤ 0.10. Mean synovial PGE₂ was 26% and 29% lower in CORT6 and CORT12 than in CON horses (<em>P</em> = 0.01), but did not differ between CORT6 and CORT12 (<em>P</em> = 0.75). There was a treatment × time interaction (<em>P</em> &lt; 0.01) where CORT12 horses had 56% higher SP at d 7, and 52% higher SP at d 28 compared with CON (<em>P</em> = 0.02). Concentration of SP was 39% higher in CON horses compared with CORT6 on d 28 (<em>P</em> = 0.03), but TA dose did not differ (<em>P</em> = 0.12). On d 28, concentrations of SP were 54% higher in mares than geldings (<em>P</em> &lt; 0.01). Both logCPII and logC2C peaked in CORT6 and CORT12 horses on d 7 (<em>P</em> &lt; 0.01), but logCPII tended to remain higher until d 14 (<em>P</em> = 0.08). Similarly, net cartilage synthesis (logCPII:logC2C) was higher in CORT6 and CORT12 than CON on d 7 (<em>P</em> &lt; 0.05) but returned to baseline by d 56. Therefore, intra-articular administration of TA reduced PGE₂, but net cartilage synthesis and SP increased regardless of TA dose. No differences between 6 or 12 mg of TA were observed, and further research is needed to establish a minimally effective dose.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105485"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948158","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":"Impacts of dietary starch on exercise-induced inflammatory markers in yearling Quarter Horses","authors":"A.N. DiSilvestro ,&nbsp;L.T. Wesolowski ,&nbsp;B.D. Williams ,&nbsp;L.K. Warren ,&nbsp;S.H. White-Springer","doi":"10.1016/j.jevs.2025.105496","DOIUrl":"10.1016/j.jevs.2025.105496","url":null,"abstract":"<div><div>In humans, intestinal microbiota are recognized to play key regulatory roles in inflammation. In horses, addition of dietary starch is known to alter the intestinal microbiome, but the relationship between diet and inflammation in horses is poorly understood. To test the hypothesis that a starch-based diet would result in greater inflammatory markers than a fiber-based diet, Quarter Horses (mean <em>±</em> SD 14 <em>±</em> 1 mo; 337 <em>±</em> 30 kg) were acclimated to a basal diet of 1% BW per day of a high fiber concentrate (36.3% NDF, 8.5% starch) and 1.5% BW per day coastal Bermudagrass hay in individual runs. Following 21 d of acclimation, horses were stratified by age, sex, and BW and randomly assigned to receive either the basal diet (CON; 7 fillies, 8 geldings) or hay plus 1% BW per day of an isocaloric, isonitrogenous starch concentrate (STARCH; 24.1% NDF, 28.7% starch; 8 fillies, 7 geldings) for 24 d. Concentrations of serum amyloid A (SAA), C-reactive protein (CRP), and plasma tumor necrosis factor (TNF)α, interleukin (IL)4, IL8, and IL10 were quantified from blood collected on d 0, d 21, and before (pre), and 0, 1, 6, 24, and 48 h after a 2-h submaximal exercise test (SET) on d 22. Data were analyzed using PROC MIXED in SAS v9.4 with a repeated effect of time and horse (diet) as a random effect; sex, time, diet, and time <em>×</em> diet were fixed effects. Regardless of diet, CRP increased and IL4, IL10, and TNFα decreased from d 0 to 21 (<em>P</em> ≤ 0.02). In response to the SET on d 22, CRP increased at 24 h in all horses (<em>P</em> &lt; 0.0001). In STARCH horses, CRP then decreased to 48 h (<em>P</em> = 0.002), returning to pre values. In CON horses, CRP decreased to 48 h (<em>P</em> = 0.05) but remained above pre (<em>P</em> = 0.0005), resulting in CON having greater CRP than STARCH horses at 48 h (<em>P</em> = 0.02). In STARCH horses, TNFα increased from pre to 1 h (<em>P</em> = 0.02), then returned to pre levels by 6 h. In CON horses, TNFα increased above pre at 24 h (<em>P</em> = 0.04) and remained elevated at 48 h (<em>P</em> = 0.0005), resulting in STARCH tending to have greater TNFα than CON horses at 48 h (<em>P</em> = 0.06). Throughout the SET, CON horses had greater IL10 than STARCH (<em>P</em> = 0.005) but SAA, IL4, and IL8 were not affected by diet. In all horses, SAA increased at 6 h, continued increasing to 24 h, then decreased to 48 h but did not return to pre (<em>P</em> ≤ 0.007). IL8 increased at 1 h, continued to increase to 6h, and remained elevated through 48 h (<em>P</em> ≤ 0.02). Following the SET, IL4 remained stable until decreasing at 48 h to below pre (<em>P</em> &lt; 0.0001). IL10 increased from pre to 0 h, then decreased at 24 h and was below pre at 48 h (<em>P</em> ≤ 0.03). Contrary to our hypothesis, these data suggest horses on a higher fiber diet may elicit a more robust acute inflammatory response in response to exercise.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105496"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948159","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":"Maintaining early equine pregnancies with injectable altrenogest: How often?","authors":"J. Loy,&nbsp;G.K. Noble,&nbsp;C.J. Scrivener,&nbsp;C.K. Smith","doi":"10.1016/j.jevs.2025.105469","DOIUrl":"10.1016/j.jevs.2025.105469","url":null,"abstract":"<div><div>Altrenogest (ALT) mimics progesterone (P₄) so is widely used for maintenance of equine pregnancies. This is despite limited evidence that inadequate maternal P₄ is a significant cause of early pregnancy loss. Daily dosing of oral ALT is impractical for long-term use and unsafe given ALT carries human health risks. As a result, using longer acting injectable ALT products is becoming increasingly widespread. Unfortunately, while safer and more practical, there is limited evidence to suggest injectable products at the recommended ALT dosage can maintain early pregnancy in mares with insufficient endogenous P₄. Thirteen fertile mares, aged 8.4 ± 1.9 years, were used to assess frequency of administration of intramuscular (IM) ALT for early pregnancy maintenance. Mares were inseminated then checked for ovulation using trans-rectal ultrasound. Once ovulation was confirmed, mares underwent pregnancy diagnosis at d 14 and recruited if pregnant. Pregnant mares were randomly assigned to a treatment group. Treatment A: 2 injections of ALT (0.3 mg/kg IM) at 7-d intervals, n = 10; treatment B: 2 injections of ALT (0.3 mg/kg IM) at 5-d intervals, n = 10; and control: 0.044 mg/kg oral ALT (treatment control) once daily for 14 d, n = 5. All treatments commenced on d 17 of gestation. Mares were administered prostaglandin (PGF_2α; 250 µg Cloprostenol IM) 1 h after treatment to induce P₄ insufficiency, confirmed though commercial P₄ assay. During treatment, mares were blood sampled daily to assess P₄ and ALT concentrations. Mares underwent trans-rectal ultrasound 4 times a week until the embryo was aborted/nonviable or a fetal heartbeat was detected at the end of the treatment period, d 31 (Group A and control) or d 27 (Group B). Aborting mares were rebred. Pregnancy data were analyzed using a chi-squared test and <em>P</em> ≤ 0.05 was considered significant. Following PGF_2α injection, serum P₄ had decreased by 84.7 ± 4.8% within 24 h and declined to &lt;1 ng/mL within 48 h. There were significant differences in pregnancy maintenance between groups (chi-squared 8.51, <em>P</em> = 0.014). Treatment B was better at maintaining pregnancies (9/10) than treatment A (3/10). There was no difference between treatment B and the control group (4/5). Injectable ALT administered every 7 d resulted in reduced pregnancy maintenance when compared with injectable treatment at 5 d intervals and daily oral treatment. If progesterone insufficiency is confirmed, administration of 0.3 mg/kg every 5 d is recommended.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105469"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948012","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":"A meta-analysis to identify factors affecting solid and liquid digesta mean retention time in equines","authors":"K. Papadakis ,&nbsp;E.M. Leishman ,&nbsp;P.S. Darani ,&nbsp;S. Cieslar ,&nbsp;J.L. Ellis","doi":"10.1016/j.jevs.2025.105434","DOIUrl":"10.1016/j.jevs.2025.105434","url":null,"abstract":"<div><div>How quickly feed passes through the equine gastrointestinal tract (GIT) or specific compartments of the GIT is an important determinant of nutrient digestion and absorption. Typically, this process is quantified by measuring mean retention time (MRT), or the average number of hours required to pass a labeled feedstuff/digesta fraction. While determinants of MRT have been studied extensively in other species resulting in empirical equations, equine data lack such quantitative summaries. The variability in experimental diets and subjects (i.e., sex, breed, age) across equine studies makes qualitative comparisons difficult. Therefore, the objective of this study was to conduct a meta-analysis across available MRT data from published equine studies to determine factors (e.g., dietary, physiological, management) that affect equine MRT and to develop predictive/descriptive equations for MRT in equines. Such equations would be useful in the prediction of feedstuff or nutrient digestibility, as well as the development of models of nutrient utilization. A systematic literature search was conducted which yielded 24 papers (144 mean observations of total-tract MRT, for solid and liquid digesta) that met the criteria for inclusion (must report MRT, and have a change in diet given). Information extracted from the papers included (as available) body weight, classification as horse or pony, age, dry matter intake, forage particle size, feed ingredients, diet nutrient composition, forage to concentrate ratio, and so on. A linear mixed model analysis treating study as a random effect was conducted to identify significant driving variables and quantify their effects on MRT across the published literature. Model fit was evaluated using visual plots, root Mean Square Prediction Error (rMSPE), and the Concordance Correlation Coefficient (CCC) statistic. For total-tract liquid digesta MRT (h), it was found that whether the equine was a horse or pony, the DMI (kg/d) and ADF (g/kg DM) content of the diet yielded the best model predictions (raw CCC: 0.712, raw rMSPE: 22.0%, conditioned CCC: 0.900, conditioned rMSPE 12.9%). For the solid digesta MRT (h) models, whether it was a horse or pony, the DMI (kg/d), the roughage percent of the diet, and the NDF (g/kg DM) content of the diet yielded the best model predictions (raw CCC: 0.469, raw rMSPE: 18.6%, conditioned CCC: 0.885, conditioned rMSPE 9.1%). These models confirm existing knowledge while developing tools to predict MRT in horses going forward, not only advancing the field of quantitative equine nutrition but also enhancing our ability to predict nutrient digestibility in horses.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105434"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947797","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":"Effects of obesity and hyperleptinemia on progesterone, equine chorionic gonadotropin, and fetal biometry during the first 70 days of pregnancy","authors":"L.L. Thorburn ,&nbsp;J.L. Sones ,&nbsp;S.B. Cousseau ,&nbsp;M.E. Autin ,&nbsp;M.F. Disher ,&nbsp;E.L. Oberhaus","doi":"10.1016/j.jevs.2025.105474","DOIUrl":"10.1016/j.jevs.2025.105474","url":null,"abstract":"<div><div>While consequences of equine obesity are well defined, the extent to which persistent hyperleptinemia (HL) affects the fetal-maternal environment warrants further exploration as HL and often accompanying leptin (Lep) resistance have been shown to perturb processes such as angiogenesis in the developing placentae of other species. Therefore, this study aims to compare endocrine, fetal, placental, and uterine factors during the first 70 d of pregnancy of mares with persistent HL versus mares with normal Lep (NL) concentrations. Plasma Lep and body condition scores (BCS; 1–9) were determined throughout the year to confirm persistent HL and obesity. Percentile-based cutoffs were used to divide mares into 2 groups. Fourteen resident mares were identified as either HL (n = 8; mean Lep 8.6 ng/mL ± 0.8; BCS 7.5; median age 15) or NL (n = 6; mean Lep 1.2 ng/mL ± 0.2; BCS 5.3; median age 16). Before breeding, plasma Lep was greater (<em>P</em> &lt; 0.0001), and BCS was higher (<em>P</em> &lt; 0.01) in mares with HL compared with NL-mares based on <em>t</em>-tests. Mares were artificially inseminated with at least 500 × 10⁶ progressively motile sperm from one proven stallion upon detection of a follicle ≥35 mm and uterine edema. Ovulation was induced with 2500 IU hCG and blood samples were collected for 6 successive days starting on the day of ovulation. Additional blood sampling occurred on d 12 and 25 and every 10 d thereafter until d 70 to characterize progesterone and eCG. Embryonic vesicle diameter was recorded on d 14 and 25. On d 70, fetuses were collected transcervically, and crown-rump length, fetal weight, and placental weight were determined. Placental and endometrial tissues were frozen for later analyses. Two-way ANOVA and <em>t</em>-tests were used to compare progesterone over time and eCG and fetal growth parameters, respectively. No differences were observed in vesicle diameter on d 14 or 25. Plasma progesterone increased after ovulation and was greater (<em>P</em> &lt; 0.001) in HL-mares on d 70. Concentrations of eCG were first detected on d 45 and remained elevated until d 70; however, no differences were found between groups. Crown-rump length, and fetal and placental membrane weights did not differ between the groups. Ongoing analyses aim to compare the transcriptome of fetal and maternal tissues between mares with HL and NL. In this study, pre-existing obesity and HL did not alter fetal biometry within the first 70 d of pregnancy, nor did they alter eCG secretion into peripheral circulation. Plasma progesterone did appear to diverge on d 70; however, further sampling would be required to determine if the divergence continues thereafter.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105474"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947956","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":"Impact of discipline on fitness improvements in university horses","authors":"S. Vigum,&nbsp;B. Fischbach,&nbsp;K. Hills,&nbsp;S.M. Strader,&nbsp;M. Pyles","doi":"10.1016/j.jevs.2025.105475","DOIUrl":"10.1016/j.jevs.2025.105475","url":null,"abstract":"<div><div>Evaluating equine fitness is crucial for optimizing training regimens and preventing injury caused by overwork. However, horses ridden by beginners often experience lighter workloads than those ridden by experienced riders, potentially increasing their risk of injury. This study aimed to (1) examine changes in fitness among university horses ridden by mixed-experience and experienced riders and (2) determine whether fitness levels vary by riding discipline. We hypothesized that horses ridden by beginners and experienced riders have lower fitness improvements compared with horses ridden by experienced riders and that fitness outcomes differ across disciplines. Adult horses (&gt;3 yr; n = 17) of various breeds and minimal exercise in the past 3 mo were used in this study. Horse use was recorded, including rider experience, duration, and discipline. To evaluate fitness, horses performed a ridden standardized exercise test (SET) at the start and end of the study with the same experienced rider. Heart rate (HR), respiratory rate (RR), blood lactate (BL), and speed were recorded at each step of the SET. SETs included: 3 min walk, 2 min trot left, 2 min trot right, 2 min canter left, 2 min canter right, and 10 min walk. A Polar H10 hand-held monitor was used to measure HR. Respiratory rate was measured by watching the horse's flank. Blood lactate was obtained via jugular venipuncture and analyzed with a hand-held monitor (Lactate Plus, Nova Biomedical). Data were compared using a mixed model ANOVA with repeated measures (SAS 9.4). Horses exercised an average of 2 to 5 h/wk during the study. Horses were ridden by beginners and experienced riders (n = 9) or by only experienced riders (n = 8). Nine horses worked primarily in western and 8 horses worked primarily in English saddles. Average speed was not different between SETs (<em>P</em> = 0.088) and was 1.33, 2.93, 4.11, and 1.37 m/s for the walk, trot, canter, and cooldown, respectively. There was a SET by time interaction for HR (<em>P</em> = 0.022). After the canter step, HR was higher in SET 1 (102 ± 3 bpm) than in SET 2 (89 ± 3 bpm; <em>P</em> &lt; 0.05). There was a main effect of SET on BL; BL was lower in SET 2 than in SET 1 (<em>P</em> = 0.0059). There was no difference in fitness parameters between disciplines or rider experience (<em>P</em> &gt; 0.05). This study demonstrated that 11 wk of consistent, moderate exercise improved equine fitness, as evidenced by reduced heart rates and blood lactate levels during SETs. These findings highlight the effectiveness of regular training in enhancing fitness, regardless of the riding discipline, offering practical insights for equine management and training. The effect of high intensity, skilled work, or beginner-only riders requires further evaluation.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105475"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947957","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":"Metagenomic functional profiling to propose the anti-inflammatory properties of probiotic supplementation","authors":"R. Jacobs,&nbsp;B. Rimal,&nbsp;M.E. Gordon","doi":"10.1016/j.jevs.2025.105517","DOIUrl":"10.1016/j.jevs.2025.105517","url":null,"abstract":"<div><div>The role of the microbiome on equine health and performance is increasingly recognized, with advancements in technologies driving rapid progress. In a recent trial, supplementation of <em>Bacillus coagulans</em> GBI-30, 6086 to horses reduced the inflammatory response to exercise. Based on these findings, the objective of this trial was to investigate mechanisms underlying this effect using metagenomic functional profiling. In a complete crossover trial, horses (n = 18) were stratified by age, BW, BCS, breed, and sex and then randomly assigned to one of 6 starting treatments including a negative and positive control (0.23 mg/kg BW flunixin meglumine at 0 h), or one of 4 probiotics (<em>B. coagulans</em> GBI-30, 6086; <em>Bacillus subtilis</em>-1; <em>B. subtilis</em>-2; or <em>Bacillus amyloliquefaciens</em>) top-dressed to their daily ration at 8 billion cfu/d in dried whey. All horses received a diet of grass hay at 2.0% of BW daily and 4.54 kg of a commercially available feed. Each 3-wk phase consisted of a 2-wk dietary acclimation followed by a 1-wk exercise challenge and sampling. On the day of exercise, horses were offered their AM ration and then subjected to a 2-h exercise test. Rectal swabs were obtained before starting exercise and then again at 0, 2, 4, 6, 8, 24, 48, and 72 h after exercise. Swabs were extracted using the <em>Quick</em>-DNA Fecal/Soil Microbe Miniprep Kit (Zymo Research, Irvine, CA) and the V3-V4 hypervariable region of the 16S rRNA gene was sequenced (Illumina, San Diego, CA). Data were denoized with DADA2 within the QIIME2 pipeline to identify amplicon sequence variants (ASVs). PICRUSt2 was used to predict microbial functions from ASVs, employing phylogenetic placement via epa-ng and MetaCyc pathway analysis. Pathway abundances were compared using Aldex2 Kruskal–Wallis test followed by Dunn's test for multiple comparisons. Only horses receiving the <em>B. coagulans</em> GBI-30, 6086 displayed a reduced inflammatory pattern therefore, only samples from that treatment and the controls were evaluated. Two pathways were identified as significantly reduced at 4 h after exercise in the <em>B. coagulans</em> GBI-30, 6086 and positive control groups (<em>P</em> &lt; 0.05). Both pathways (PWY-4361 and PWY-7527) are related to methionine biosynthesis, which is associated with regulation of inflammation. It appears that through regulation of these pathways, the probiotic administration is attenuating the inflammation. In addition, this is the first known use of metagenomic pathway analysis to suggest a mechanism behind anti-inflammatory probiotic efficacy in horses.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105517"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948027","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":"Investigating genetic variants and pedigree-based diversity in Brazil's Friesian horse population","authors":"I. Amarante ,&nbsp;F. Araujo ,&nbsp;L.N.R. Patterson","doi":"10.1016/j.jevs.2025.105491","DOIUrl":"10.1016/j.jevs.2025.105491","url":null,"abstract":"<div><div>The Friesian horse, recognized for its striking appearance, was established as a breed studbook in 1879 and remains popular in media. Despite its allure, the breed suffers from several genetic pathologies, including hydrocephaly (<em>B3GALNT2</em>, c.1423C &gt; T), dwarfism (<em>B4GALT7</em>, c.50G &gt; A) and distichiasis (ECA13:g.178714_195130del), alongside conditions of unknown origin such as megaesophagus, retained placenta, insect bite hypersensitivity, aortic rupture, and chronic idiopathic anhidrosis. The breed underwent a significant bottleneck early in its development, and 2 decades ago (2005) had an effective number of ancestors (<em>Nae</em>) of 16, around the same time as the first importations from the Netherlands to Brazil occurred. As of 2025, the Friesian Studbook in Brazil has fewer than 500 registered horses, raising concerns about a secondary geographic bottleneck and undesired genetic trait frequencies in this subpopulation. To assess potential pedigree-based detrimental effects, we analyzed data from 366 Friesians registered in Brazil, tracing pedigrees to their earliest recorded ancestors using global databases with the PurgeR package. Commercial genetic testing was conducted on 12 individuals actively-breeding, unrelated by parents and grandparents (3.27% of the total population) for known pathogenic, color and behavior variants of interest. Pedigree analysis indicated a reduced <em>Nae</em> of 11.93—lower than previous global population estimates—and an effective population size (<em>Ne</em>) of 33.03, with pedigree-based inbreeding coefficients (<em>F_ped</em>) ranging from 5.84% on individuals with equivalent complete generations (<em>t</em>) of 6.1, to 35.14% with <em>t</em> of 11.7. Genetic testing resulted in a 33% carrier rate for dwarfism and 16.6% for hydrocephaly. We also identified 2 individuals as <em>HPS5^EDXW1/EDXW3</em>, and one individual as <em>KIT^W20/+</em>, variants associated with white spotting patterns in other horse breeds, despite no phenotypic expression of white in the individuals. Additionally, we observed allelic heterogeneity in the <em>DRD4</em> temperament locus, where <em>DRD4^G/G</em> = 75%, <em>DRD4^G/A =</em> 16.7% and <em>DRD4^A/A =</em> 8.3%, the latter associated with a higher vigilance phenotype. The pedigree-based probability of homozygosity for recessive alleles on a locus being identical by descent in this population is estimated as 10.7% (SD ± 3%), reiterating the importance of genetic testing for selection. These findings underscore the critical need for genetic testing and population monitoring to preserve genetic diversity and mitigate health risks in the Friesian population, particularly within isolated geographic subgroups.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105491"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947802","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":"Modelling equine pre-cecal digestible crude protein using feedstuff crude protein and fiber composition","authors":"R.W. Springer ,&nbsp;K.B. Wellmann ,&nbsp;T.A. Wickersham ,&nbsp;T.N. Jones","doi":"10.1016/j.jevs.2025.105494","DOIUrl":"10.1016/j.jevs.2025.105494","url":null,"abstract":"<div><div>Protein digestion and the absorption of amino acids and small peptides occurs in the small intestine of the horse. Current NRC protein requirements are based on crude protein (CP); however, distribution of protein in feedstuffs between cell contents and cell wall affects protein digestion in the foregut. Equine nutrient requirement models use a widely available laboratory assay, neutral detergent soluble crude protein (NDSCP) to quantify pre-cecal digestible crude protein (pcdCP), a predictor to determine if protein requirements are met. Although pcdCP can be determined in the laboratory, development of linear regression models based on more common assays are potentially useful for predicting protein availability in the foregut at a lower cost. Therefore, our study objective was to develop linear regression models to predict pcdCP using CP and fiber composition in feedstuffs common to equine diets. Data were collected from the 2023 cumulative Dairy One© Feedstuff Composition Library. Feedstuffs were selected based on having an n ≥50 for each individual nutrient analysis used for model development (CP, neutral detergent insoluble crude protein [NDICP], neutral detergent fiber [NDF], acid detergent fiber, acid detergent lignin). Feedstuff NDSCP was calculated as NDSCP = CP − NDICP, and pcdCP was calculated as pcdCP = 0.9 × NDSCP. Feedstuffs were categorized into 4 groups (CAT): forages; whole and processed grains; grain byproducts; oilseeds and oilseed meals. Data were analyzed using R (v4.4.0). Model variable selection of feedstuff nutrients was performed using a Pearson correlation. Models were ranked using the Akaike information criterion (AICc) and AICc weights (AICcWt). Model adjusted (adj.) R² was used to determine explanatory power of each model. Significance for a variable slope was set at <em>P</em> ≤ 0.05. The model using CP+NDF (pcdCP [g/kg DM] = 5.654 + 0.7615 × CP − 0.0313 × NDF) was the highest-ranked model (AICcWt = 0.95; adj. R² = 0.987). Accounting for categorical differences (CP+NDF+CAT) decreased explanatory power (adj. R² = 0.986) and predictor power (AICcWt = 0.05). Furthermore, categorical adjustments were not significant (<em>P</em> &gt; 0.15) and likely accounted for in the base model using NDF. No other models were within the threshold of ΔAICc <em>≤</em>10.0. Overall, pcdCP could be predicted with high precision using only CP and NDF as predictor variables, both of which have been used to predict CP digestibility. These results indicate that more precise estimates of small intestine absorbable protein supply may be attained through further model development and evaluation of protein fractionation in feedstuffs.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105494"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947803","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}