Equine metabolism encompasses the biochemical processes that occur within horses to maintain life, including the conversion of food into energy, the synthesis of necessary compounds, and the elimination of waste products. These processes are essential for supporting various physiological functions such as growth, reproduction, and physical performance. Key components of equine metabolism include carbohydrate, fat, and protein metabolism, each of which contributes to the overall energy balance and health of the horse. Factors influencing metabolic rate and efficiency in horses include age, breed, diet, exercise, and health status. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, regulation, and implications of metabolic processes in equine physiology.
Breckenridge WC, Kuksis A.The triglyceride compositions of the milk fats of man, dog, guinea pig, cow, sheep, goat, and horse were compared by gas-liquid chromatography of the intact triglycerides and of the butyl esters of the component fatty acids. The milk fats of man, dog, and guinea pig, which were largely made up of long-chain fatty acids, showed a common pattern with major contributions made by the glycerides with 48-54 acyl carbon atoms. The milk fats of cow, sheep, and goat, which were rich in short-chain acids, showed significant proportions of triglycerides with 28-54 acyl carbon atoms. Horse milk, which con...
Peña FJ, Martín-Cano FE, Becerro-Rey L, Ortega-Ferrusola C, Gaitskell-Phillips G, da Silva-Álvarez E, Gil MC.The mammalian ejaculate is very well suited to proteomics studies. As such, research concerning sperm proteomics is offering a huge amount of new information on the biology of spermatozoa. Among domestic animals, horses represent a species of special interest, in which reproductive technologies and a sizeable market of genetic material have grown exponentially in the last decade. Studies using proteomic approaches have been conducted in recent years, showing that proteomics is a potent tool to dig into the biology of the stallion spermatozoa. The aim of this review is to present an overview of...
Raspa F, Chessa S, Bergero D, Sacchi P, Ferrocino I, Cocolin L, Corvaglia MR, Moretti R, Cavallini D, Valle E.Diet is one of the main factors influencing the intestinal microbiota in horses, yet a systematic characterization of the microbiota along the length of the digestive tract in clinically healthy horses, homogenous for age and breed and receiving a specific diet is lacking. Unassigned: The study used 16S rRNA amplicon sequencing to characterize the microbiota of the intestinal tracts of 19 healthy Bardigiano horses of 14.3 ± 0.7 months of age fed one of two diets. Nine horses received a high-starch diet (HS), and ten horses received a high-fiber diet (HF). After 129 days, the horse...
Pardié M, Kalpokas I, Freccero F, Castagnetti C, Meikle A.The aim of this study was to determine the effect of body condition score (BCS) on metabolic and endocrine parameters in pregnant Criollo mares (n=41), which were categorized according to their BCS as obese (7 to 9 BCS, n=26) or normal (5 to 7, n=15). Blood samples were taken during gestation in 3 periods: between 3.5 and 5 months (I), 8 and 9 months (II) and in the last month of gestation (III). The data was analyzed in the statistical model by mixed procedures, including BCS, gestational period and their interaction as fixed effects. BCS was only different in period I, as normal mares increa...
Hernández-Avilés C, Ramírez-Agámez L, Weintraub ST, Scoggin CF, Davis BW, Raudsepp T, Varner DD, Love CC.Thoroughbred stallions that carry a double-homozygous genotype A/A-A/A for SNPs rs397316122 and rs69101140 in exon 5 of the FKBP6 gene (chr13; EquCab3.0) are uniquely subfertile due to impaired acrosomal exocytosis (IAE). In this study, the sperm proteome in frozen/thawed semen from subfertile Thoroughbred stallions was studied and compared to that of frozen/thawed sperm from fertile Thoroughbred stallions. A total of 2,220 proteins was identified, of which 140 proteins were found to be differentially abundant in sperm from the subfertile stallions compared to that of fertile stallions (83 les...
Hallowell KL, Dembek K, Horne CR, Knych HK, Messenger KM, Schnabel LV.Steroid-associated laminitis remains a major concern with use of corticosteroids in horses. Individual case factors such as joint pathology, pre-existing endocrinopathies, or corticosteroid type, dose, and timing influencing steroid-induced laminitis risk have not been investigated. This study aimed to determine if systemic absorption of triamcinolone acetonide (TA) varies between intrasynovial (antebrachiocarpal) and extrasynovial (sacroiliac) injection sites, and to determine the effects of TA absorption on glucose, insulin, cortisol, and adrenocorticotropic hormone (ACTH). Twenty adult hors...
Fresa K, Catandi GD, Whitcomb L, Gonzalez-Castro RA, Chicco AJ, Carnevale EM.Obesity is a complex disease associated with augmented risk of metabolic disorder development and cellular dysfunction in various species. The goal of the present study was to investigate the impacts of obesity on the metabolic health of old mares as well as test the ability of diet supplementation with either a complex blend of nutrients designed to improve equine metabolism and gastrointestinal health or L-carnitine alone to mitigate negative effects of obesity. Mares (n = 19, 17.9 ± 3.7 years) were placed into one of three group: normal-weight (NW, n = 6), obese (OB, n = 7...
Amiri Roudbar M, Rosengren MK, Mousavi SF, Fegraeus K, Naboulsi R, Meadows JRS, Lindgren G.Elite performing exercise requires an intricate modulation of the blood pressure to support the working muscles with oxygen. We have previously identified a genomic regulatory module that associates with differences in blood pressures of importance for elite performance in racehorses. This study aimed to determine the effect of the regulatory module on the protein repertoire. We sampled plasma from 12 Coldblooded trotters divided into two endothelial regulatory module haplotype groups, a sub-elite performing haplotype (SPH) and an elite performing haplotype (EPH), each at rest and exercise. Th...
Grob AJ, Delarocque J, Feige K, Warnken T.In insulin dysregulation, hyperinsulinemia (HI) can be accompanied by peripheral insulin resistance (IR) in horses, which can be diagnosed with an insulin-tolerance test (ITT). The administration of 0.1 IU/kg body weight of recombinant regular human insulin (RHI) should elicit a 50 % reduction of the initial blood glucose concentration at 30 min after insulin administration in insulin sensitive horses. Compared to RHI, porcine zinc insulin (PZI) is veterinary-approved and therefore easier accessible for many practitioners. The aim of this study was to compare the insulin and glucose dynami...
Luis-Calero M, Ortiz-Rodríguez JM, Fernández-Hernández P, Muñoz-García CC, Pericuesta E, Gutiérrez-Adán A, Marinaro F, Embade N, Conde R....In vitro embryo production is a highly demanded reproductive technology in horses, which requires the recovery (in vivo or post-mortem) and in vitro maturation (IVM) of oocytes. Oocytes subjected to IVM exhibit poor developmental competence compared to their in vivo counterparts, being this related to a suboptimal composition of commercial maturation media. The objective of this work was to study the effect of different concentrations of secretome obtained from equine preovulatory follicular fluid (FF) on cumulus-oocyte complexes (COCs) during IVM. COCs retrieved in vivo by ovum pick up (OPU) ...
Hisaeda K, Ono T, Kadekaru S, Hata A, Miyama TS, Kutara K, Sugimoto K, Hiasa Y, Ohzawa E, Kunieda T, Iwata E, Kitagawa H.Plasma or serum amino acids are used to evaluate nutritional status and metabolic disorders. In this study, we aimed to set reference values of serum amino acid concentrations in the Noma horse, a Japanese native horse. Thirty-one horses were classified into six age groups: neonatal foal (0-4 days), foal (0.5-1 years), youth (5 years), middle age (10 years), old (15 years), and extra-old (>20 years). Horses >5 years of age were analyzed together as the adult group. In the adult horses, there were no significant differences among the serum amino acid concentrations of each age group. The ...
Menzies-Gow NJ, Knowles EJ.Laminitis is a common and painful condition of the equine foot and approximately 90% of cases are associated with insulin dysregulation (ID) that is a central feature of the common endocrine disorder equine metabolic syndrome (EMS) and occurs in a subset of animals with pituitary pars intermedia dysfunction. Additional features of EMS include obesity, altered circulating concentrations of adipokines (particularly adiponectin and leptin) and hypertriglyceridaemia. Obesity, ID, hypoadiponectinaemia, hyperleptinaemia and an altered plasma lipid profile are also features of human metabolic syndrom...
Teles Filho ACA, Sanchez DJD, Viana AGA, Sheheryar S, Guerreiro DD, Bustamante-Filho IC, Martins AMA, Sousa MV, Ricart CAO, Fontes W, Moura AA.The present study was conducted to investigate the global proteome of 8-day-old equine blastocysts. Follicular dynamics of eight adult mares were monitored by ultrasonography and inseminated 24 h after the detection of a preovulatory follicle. Four expanded blastocysts were recovered, pooled, and subjected to protein extraction and mass spectrometry. Protein identification was conducted based on four database searches (PEAKS, Proteome Discoverer software, SearchGUI software, and PepExplorer). Enrichment analysis was performed using g:Profiler, Panther, and String platforms. After the elimina...
Wang J, Ren W, Sun Z, Han Z, Zeng Y, Meng J, Yao X.This study conducted a thorough analysis of the myofiber type composition in the extensor digitorum longus muscle (EDL) and soleus muscle (SOL) of Kazakh horses, across different genders (male and female). The results showed significant differences in myofiber type composition between EDL and SOL, with a higher proportion of Type I fibers in SOL muscles and a greater prevalence of Type II fibers in EDL muscles. Additionally, the myofiber diameter in Kazakh horses was relatively small, potentially related to the tenderness and edible quality of their muscles. Using high-throughput sequencing te...
Stothart MR, McLoughlin PD, Medill SA, Greuel RJ, Wilson AJ, Poissant J.Gut microbiomes are widely hypothesised to influence host fitness and have been experimentally shown to affect host health and phenotypes under laboratory conditions. However, the extent to which they do so in free-living animal populations and the proximate mechanisms involved remain open questions. In this study, using long-term, individual-based life history and shallow shotgun metagenomic sequencing data (2394 fecal samples from 794 individuals collected between 2013-2019), we quantify relationships between gut microbiome variation and survival in a feral population of horses under natural...
Takahashi K, Mukai K, Ebisuda Y, Sugiyama F, Yoshida T, Hatta H, Kitaoka Y.Evidence suggests that positive pacing strategy improves exercise performance and fatigue tolerance in athletic events lasting 1-5 min. This study investigated muscle metabolic responses to positive and negative pacing strategies in Thoroughbred horses. Eight Thoroughbred horses performed 2 min treadmill running using positive (1 min at 110% maximal O uptake [V̇Omax], followed by 1 min at 90% V̇Omax) and negative (1 min at 90% V̇Omax, followed by 1 min at 110% V̇Omax) pacing strategies. The arterial-mixed venous O difference did not significantly differ between the two strategies. Pl...
Michanek P, Bröjer J, Lilliehöök I, Fjordbakk CT, Löwgren M, Hedeland M, Bergquist J, Ekstrand C.Canagliflozin (CFZ) is a sodium-glucose cotransporter-2 inhibitor that has shown promising results as a drug for the treatment of insulin dysregulation in horses. Even though CFZ is used clinically, no pharmacokinetic data has previously been published. In this study, the pharmacokinetics of CFZ after administration of a single oral dose of 1.8 mg/kg in eight healthy Icelandic horses was examined. Additionally, the effect of treatment on glucose and insulin levels in response to a graded glucose infusion was investigated. Plasma samples for CFZ quantification were taken at 0, 0.33, 0.66, 1, ...
Page AE, Johnson M, Parker JL, Jacob O, Poston R, Adams AA, Adam EN.Intra-articular corticosteroids are a popular treatment choice for joint-associated pain and inflammation in horses despite recent work on the metabolic effects of these drugs. The goal of this project was to compare metabolic effects between intra-articular (IA) triamcinolone acetonide (TA) and an autologous protein solution (APS). Five mixed-breed geldings (4-9 years) were utilized for this project. Three identical and consecutive 28-day treatment blocks were used, with metacarpophalangeal IA treatments consisting of equal volumes of saline, a commercially available APS, or 9 mg of TA. Regul...
Semik-Gurgul E, Pawlina-Tyszko K, Gurgul A, Szmatoła T, Rybińska J, Ząbek T.DNA methylation and microRNA (miRNA) expression are epigenetic mechanisms essential for regulating tissue-specific gene expression and metabolic processes. However, high-resolution transcriptome, methylome, or miRNAome data is only available for a few model organisms and selected tissues. Up to date, only a few studies have reported on gene expression, DNA methylation, or miRNA expression in adult equine tissues at the genome-wide level. In the present study, we used RNA-Seq, miRNA-seq, and reduced representation bisulfite sequencing (RRBS) data from the heart, lung, and liver tissues of healt...
Lashkari S, Beblein C, Christensen JW, Jensen SK.High-starch diets may affect equine hindgut microbiota and increase blood glucose levels, which may cause unwanted physiological changes, but may also elicit behavioural changes such as increased fear reactions. The purpose of the current study was to feed a high starch (300) and low fat (43; HS_LF) or a low starch (60) and high fat (85; LS_HF, g/kg of DM) concentrate within the available commercial range and investigate how muscle endurance and fear reactions of horses respond to different diets. Twenty Danish Warmblood stallions (4 years) were randomly allocated to two treatments: LS_HF (n...
Becerro-Rey L, Martín-Cano FE, Fabres Robaina Sancler-Silva Y, Gil MC, Ortega-Ferrusola C, Aparicio IM, Gaitskell-Phillips G, da Silva-Álvarez E....Conservation of equine semen in the liquid state is a central procedure in horse breeding and constitutes the basis of associated reproductive technologies. The intense mitochondrial activity of the stallion spermatozoa increases oxidative stress along the storage period, leading to sperm demise within 24-48 h of storage, particularly when maintained at room temperature. Recently, the relationship between metabolism and oxidative stress has been revealed. The study aimed to extend the period of conservation of equine semen, at room temperature through modification of the metabolites present i...
Li X, Du M, Liu Y, Wang M, Shen Y, Xing J, Zhang L, Zhao Y, Bou G, Bai D, Dugarjaviin M, Xia W.During follicular development, changes in the composition of the follicular fluid are synchronized with the development of oocytes. Our aim was to screen the key factors affecting oocyte maturation and optimize the in vitro culture protocol by understanding the changes of proteins and metabolites in follicular fluid. Follicles are divided into three groups according to their diameter (small follicle fluid (SFF): 10 mm < d < 20 mm; medium follicle fluid (MFF): 20 mm < d < 30 mm; large follicle fluid (LFF): 30 mm < d). Proteins and metabolites from the follicular fluid w...
Sibthorpe PEM, Fitzgerald DM, Sillence MN, de Laat MA.Equine insulin dysregulation (ID) is a significant metabolic problem because the hyperinsulinaemia that develops increases the animal's risk of developing laminitis, a debilitating foot condition. The role of gastrointestinal factors, such as incretin hormones, in the pathogenesis of ID and hyperinsulinaemia in horses is poorly understood, particularly in comparison to other species. Glucagon-like peptide-2 (GLP-2) is an intestinotrophic peptide released from L cells in the gastrointestinal tract and is implicated in metabolic dysfunction in other species. The aim of this study in vitro was to...
Jacquay ET, Harris PA, Adams AA.It is unknown whether short-term transportation affects endocrine responses similarly in horses with and without insulin dysregulation (ID). Objective: To characterise the effect of short-term transportation on stress parameters and insulin responses to an oral sugar test (OST) in horses with and without ID. Methods: Longitudinal cohort study. Methods: Fourteen adult non-pregnant, non-PPID mares of mixed light breeds were grouped as either ID (n = 7) or non-ID (n = 7) based on endocrine testing. Over 2 weeks, horses were transported once, in groups of 3-4 in a horse trailer on a roun...
Ishii H, Shigematsu R, Takemoto S, Ishikawa Y, Mizobe F, Nomura M, Arima D, Kunii H, Yuasa R, Yamanaka T, Tanabe S, Nagata SI, Yamada M, Leung GN.Osilodrostat, used to treat Cushing's disease, exhibits an anabolic effect, leading to its classification as a prohibited substance in horseracing and equestrian sports. This study reports the characterization of osilodrostat metabolites in horse urine and elucidates its metabolic pathways for the first time for doping control purposes. Methods: Osilodrostat was administered nasoesophageally to four thoroughbreds (one gelding and three mares) at a dose of 50 mg each. Potential metabolites were extensively screened via our developed generic approach employing differential analysis to identify m...
Kerley BS, Harris P, Lea K, McClendon M, Adams AA.Forage low in nonstructural carbohydrates (NSC) is recommended for insulin dysregulated (ID) horses, indicating the importance of an accurate forage analysis. However, it remains to be fully understood how handling forage samples pre-analysis impacts nutrient values. The objective of this study was to compare the effect of fresh-forage storage-handling methods: microwave-oven (MO; 9kw; 70s then stored at -20℃), room temperature (20℃), 3℃, -20℃, and -80℃. Subsamples collected from a mixed-grass pasture and a ryegrass plot were analyzed for crude protein (CP), water soluble carbohydrat...
Serteyn D, Storms N, Mouithys-Mickalad A, Sandersen C, Niesten A, Duysens J, Graide H, Ceusters J, Franck T.Laminitis in horses is a crippling condition marked by the deterioration of the dermal-epidermal interface, leading to intense lameness and discomfort, often necessitating euthanasia. This study aimed to establish an in vitro model of laminitis using a continuous keratinocyte cell line exposed to anoxia-reoxygenation and an activated neutrophil supernatant. A significant decrease in the keratinocytes' metabolism was noted during the reoxygenation period, indicative of cellular stress. Adding muscle-derived mesenchymal stem/stromal cells during the reoxygenation demonstrated a protective effect...
Philip M, Kal AKK, Subhahar MB, Karatt TK, Graiban FM, Ajeebsanu MM, Joseph M, Jose SV.Phosphodiesterase 4 (PDE4) inhibitors are a newer class of drugs that induce bronchodilation and have anti-inflammatory effects, making them susceptible to misuse as performance enhancers in competitive sports. Methods: This study explores the metabolic conversion of PDE4 inhibitor ibudilast in thoroughbred horses after oral administration and in vitro using equine liver microsomes and Cunninghamella elegans. A liquid chromatography-high resolution mass spectrometry method was used to postulate the plausible structures of the detected metabolites. Results: A total of 20 in vivo metabolites wer...
Martínez-Aranzales JR, Córdoba-Agudelo M, Pérez-Jaramillo JE.Crib-biting is a stereotyped oral behavior with poorly understood etiology and pathophysiology. The relationship between the gut microbiome and brain function has been described in behavioral disorders such as schizophrenia, depression and anxiety in humans. In horses, studies of behavioral problems and the microbiome are very limited. This study aimed to characterize the fecal microbiome and the predicted functional profile of horses with and without aerophagia. Fecal samples were collected from 12 Colombian Creole Horses of both sexes, divided into two groups: group 1, composed of six horses...
The objective of the present study was to characterize the nutritional composition, fatty acid profile, and IgG concentration of the milk produced by Chilean Corralero horse (CCH) mares from breeding farms located in southern Chile. Forty-five milk samples were collected from three of the biggest breeding farms (coded as A, B and C) specialized in breeding and selection of CCH in Chile (15 mares sampled per farm). Farms differed in days in milk (DIM). A negative association between DIM and ash, milk protein, milk solids, saturated fatty acids (SFA), and gross energy (GE) was found, whereas DIM...
Zemek CHK, Kemp KL, Bertin FR.Characterizing the lipid response to an oral glucose test (OGT) might improve our understanding of Equine Metabolic Syndrome. Objective: To describe the effects of an OGT on lipid metabolism and determine the value of measuring triglyceride and nonesterified fatty acid (NEFA) concentrations in hyperinsulinemic (HI) and insulin-resistant (IR) horses. Methods: Twenty horses including 7 HI-IR horses, 4 HI-non-IR horses, and 9 non-HI-non-IR horses (control). Methods: Cross-sectional design. Horses underwent an OGT, with blood samples collected at 0, 60, 90, and 120 minutes. Insulin, glucose, tri...
