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.
Kayar SR, Hoppeler H, Essen-Gustavsson B, Schwerzmann K.A morphometric analysis was performed on horse muscle tissue to quantify mitochondrial distribution relative to capillaries. Samples of M. vastus medialis, M. semitendinosus, M. masseter and M. cutaneus thoracicus were preserved in a glutaraldehyde fixative for electron microscopy, or frozen for biochemical and histochemical analysis. These four muscles varied from highly oxidative in type, consisting nearly completely of type I fibres, in masseter, to highly glycolytic, primarily type IIb fibres, in cutaneus. In all four muscles, mitochondria were found in highest volume density near capillar...
Stamer M, Sumpf D.The live weight development of young warm-blooded stallions at the age of 0 to 30 months of life was investigated in order to derive their energy and protein requirement. The aim of the studies was the derivation of a standard curve for the course of growth. Choice of the best suited model and the corresponding calculations were one of the main investigation objects. The mathematical function developed by Janoschek provided a relatively good description of the material.
Van Beek H, Baars AJ.Metallothioneins (MTs) were separated and quantitated by reversed-phase high-performance liquid chromatography (RP-HPLC), in direct combination with atomic absorption spectrometry (AAS) for quantitation of the metal contents in MTs. MTs were eluted from an RP-8 column with a gradient of Tris buffer pH 7.0 and methanol, and were detected by UV absorbance (220 nm). Commercially available purified MTs from horse kidney and rabbit liver were analyzed for purity and metal composition. One lot of horse kidney yielded only 50% of the estimated value. In some cases, the certified metal content differe...
Groenendyk S, English PB, Abetz I.The components of the daily external water and electrolyte balances of five normal Standardbred geldings with a mean body weight of 427 kg, were determined over 14 day periods. The mean value of daily total water intake (a summation of free, combined and metabolic water intake) for the group was 27.6 litres, that is, 64.4 ml/kg body weight, while mean values for ambient temperature and humidity ranged from 16 to 25 degrees C and 55.4 to 75.5 per cent, respectively. The mean daily urine volume of 9.9 litres (23.2 ml/kg) for the group, was found to exceed the mean faecal water output of 7.2 litr...
Tai CL, Wang C, Weckman TJ, Popot MA, Woods WE, Yang JM, Blake J, Tai HH, Tobin T.To improve the sensitivity and specificity of screening for etorphine in horses, an 125I-labeled etorphine analog was synthesized and an antibody to etorphine was raised in rabbits. A radioimmunoassay (RIA) for etorphine was developed, using these reagents. Bound and free 125I-labeled etorphine was separated by a double-antibody method that reduced interference from materials associated with equine urine. The 125I-labeled etorphine binding was rarely greater than 250 pg of background etorphine equivalents/ml in raw urine and was 100 pg/ml in hydrolyzed urine. The 125I-RIA was capable of detect...
Araújo-Viel MS, Juliano MA, Oliveira L, Prado ES.The effect of secondary-subsite interactions on the catalytic efficiency of horse urinary kallikrein was studied using as substrates oligopeptides and peptidyl-4-nitroanilides with L-Arg at P1. The known secondary specificity of tissue kallikreins for hydrophobic residues at P2 was also demonstrated for horse urinary kallikrein and a higher preference of this enzyme for L-Phe over L-Leu at P2 was evident. Interaction of subsites S3 with D-Pro and D-Phe enhanced the catalytic efficiency but tripeptidyl-4-nitroanilides with acetyl-D-Pro, L-Pro and acetyl-L-Pro at P3 were no better substrates tha...
Frape DL.There is no clear evidence that the chronic requirement for any non-energy yielding nutrient rises in proportion as the energy requirement increases with hard work. The need for protein, and probably that for calcium, remain a function of bodyweight daily. Some proportionality with energy may exist for certain nutrients, although the evidence has not been adduced. For example, because of an increase in both the proportion and amount of propionic acid in the volatile fatty acids of caecal contents, the tissue requirement for vitamin B12 may rise with an increase in the rate of energy metabolism...
Rose J, Rose E.This article discusses some of the rationales for the medical management of colic during the initial treatment period. The issue of colic pain control and the masking of clinical signs that may indicate severe gastrointestinal disease is addressed. Therapeutic considerations related to dehydration, metabolic imbalances, hemostatic disorders, antimicrobial therapy, fecal consistency, gastrointestinal decompression, and regulation of intestinal motility are reviewed.
Thompson AJ, Swash M, Cox EL, Ingram DA, Gray A, Schwartz MS.In a woman with a slowly progressive adult onset proximal myopathy, muscle biopsy showed storage of PAS positive material in type 1 fibers. This material consisted of a branched chain polysaccharide associated with a mucoprotein. No abnormality of glycogen-pathway enzymes was detected. This suggested that this polysaccharide accumulation occurred because the polysaccharide was laid down in a non-bioavailable form. The clinical and histochemical features in this patient and in the few similar reported cases indicate that polysaccharide storage myopathy is a distinct entity that is allied to the...
Johansson J, von Bahr-Lindström H, Jeck R, Woenckhaus C, Jörnvall H.The primary structure of the mitochondrial form of horse liver aldehyde dehydrogenase has been determined, utilizing peptide analyses and homology with other enzyme forms. The subunit exhibits N-terminal heterogeneity in size similar to that for the corresponding human mitochondrial protein, the longest form having 500 residues. Catalase was identified as a contaminant of the preparations. All four pairs within a set of aldehyde dehydrogenases can now be compared, including the same two species variants (horse and human) for both the cytosolic and mitochondrial enzyme, revealing characteristic...
Harris P, Snow DH.To study the effect of short term high intensity exercise on plasma lactate, potassium, sodium and chloride concentrations, five Thoroughbred horses were galloped on a treadmill at a 5 degree incline. Following a standardised warm-up period, they were galloped at 8, 10, or 12 metres/sec for 2 mins. One horse also galloped at 14 metres/sec for 1.5 mins. Sequential arterial and/or venous blood samples were collected during exercise and recovery. At 12 metres/sec, the effect of different recovery modes, ie, standing, walking or trotting, on the electrolytes was also examined. There was a progress...
Evans DL, Rose RJ.A rapid incremental treadmill exercise test was used to determine the repeatability of the following measurements in exercising horses: maximal oxygen consumption (VO2max), maximal heart rate (HRmax), velocity at a heart rate of 200 beats/min (V-200), oxygen consumption at a heart rate of 200 beats/min (VO2-200), oxygen consumption at HRmax (VO2-HRmax), work rate at a heart rate of 200 beats/min (W-200), work rate at HRmax (W-HRmax) and treadmill velocity at HRmax (V-HRmax). Six Standardbred geldings were exercised on three separate occasions on a treadmill set at an inclination of 6 degrees. ...
Manohar M, Goetz TE, Holste LC, Nganwa D.Diaphragmatic O2 and lactate extraction were studied in 10 healthy ponies at rest and during treadmill exercise. The phrenic vein was aseptically catheterized via a lateral thoracotomy 8-35 days before the study. Arterial and phrenic venous blood samples were obtained simultaneously at rest and at 30-s intervals during 4 min of exertion. Three levels of exertion were studied (moderate, 10 mi/h; heavy, 15 mi/h; maximal, 20 mi/h), and a rest period of at least 90 min was allowed between them. Each pony was studied twice at least 2-3 days apart. At rest the diaphragmatic venous PO2, O2 saturation...
Clarke LL, Ganjam VK, Fichtenbaum B, Hatfield D, Garner HE.The effect of feeding frequency and associated meal size on the renin-angiotensin-aldosterone system (RAAS) in seven horses was examined. A daily maintenance ration of hay-grain pellets was provided either as a multiple feeding regimen (MF), in which the ration was divided into six equal portions fed at 4-h intervals, or as a single large feeding (SF) given from 9 A.M. until 11 A.M. Plasma renin activity (PRA), aldosterone (PAC), cortisol (PCC), protein concentration (TP), packed cell volume (PCV), and serum sodium and potassium were measured serially. To prevent significant RAAS stimulation d...
Boyer RF, Clark HM, LaRoche AP.The reductive release of ferritin iron by several naturally occurring o-diphenols was studied. The initial rate of iron release was quantified by spectrophotometric measurement of the Fe(ferrozine)3(2+) complex, which absorbs maximally at 562 nm. The initial rate of iron release was dependent upon o-diphenol concentration, but not on the concentration of the chromophoric chelating agent, ferrozine, Stoichiometric measurements resulted in a ratio of 2Fe(II) released per molecule of o-diphenol. The series of o-diphenols studied included, caffeic acid, chlorogenic acid, dihydrocaffeic acid, 3,4-d...
Freeman DW, Potter GD, Schelling GT, Kreider JL.Nitrogen metabolism was measured in five mature geldings performing varying levels of work that simulated race training. Following an initial maintenance period without forced exercise, workload was increased in succeeding 18-d periods by doubling the distance the horses were galloped in each period from period 2 through 4. A 4-d N balance experiment was conducted at the end of each 18-d period. The maximum distance galloped daily, which was in period 4, was repeated in period 5. Then, workloads were decreased through period 7. Nitrogen balance was determined in two additional periods, 8 and 9...
Rose RJ, Hodgson DR, Kelso TB, McCutcheon LJ, Reid TA, Bayly WM, Gollnick PD.This study determined maximal O2 uptake (VO2max), maximal O2 deficit, and O2 debt in the Thoroughbred racehorse exercising on an inclined treadmill. In eight horses the O2 uptake (VO2) vs. speed relationship was linear until 10 m/s and VO2max values ranged from 131 to 153 ml.kg-1.min-1. Six of these horses then exercised at 120% of their VO2max until exhaustion. VO2, CO2 production (VCO2), and plasma lactate (La) were measured before and during exercise and through 60 min of recovery. Muscle biopsies were collected before and at 0.25, 0.5, 1, 1.5, 2, 5, 10, 15, 20, 40, and 60 min after exercis...
Gibbs PG, Potter GD, Schelling GT, Kreider JL, Boyd CL.Mature ponies fitted with permanent ileal cannulas were used in a 3 X 3 Latin square experiment to quantify prececal, postileal and total tract digestion of hay protein. Coastal Bermuda grass (CB), containing 11.7% crude protein, and two qualities of alfalfa, containing 15.0% (low-protein alfalfa; LA) and 18.1% (high-protein alfalfa; HA) crude protein, were fed in coarsely chopped form at 2% of body weight daily. Total tract apparent digestibility of the N in HA (73.8%) was higher than that in CB (57.0%; P less than .05) and was slightly higher than that in LA (66.1%; P less than .10). Nitroge...
Stull CL, Rodiek AV.Two experiments were conducted to determine the response of blood glucose, insulin and cortisol levels to four common equine diets. Experiment 1 was designed to determine the diurnal variation of glucose and two glucoregulatory hormones, insulin and cortisol, in four fasting geldings. No diurnal variation was observed in either glucose or insulin levels during the 24-h sampling period. However, cortisol levels did exhibit a circadian rhythm, with elevated values observed in the morning and low values in the evening. Experiment 2 investigated the response of glucose, insulin, cortisol and selec...
Greenblatt DJ, Engelking LR.Adult female ponies (130-225 kg) with chronically implanted external biliary fistulas (T-tubes) participated in three-way cross-over studies using either i.v. lorazepam (10 mg) or acetaminophen (2 g), two model drugs biotransformed mainly by hepatic conjugative reactions. The objectives were to determine the systemic pharmacokinetics, urinary and biliary excretion and degree of enterohepatic circulation (EHC) of these compounds. Trial conditions were: A: EHC intact, with blood and urine, but not bile, collected after i.v. drug administration; B: EHC interrupted, with blood, urine and bile coll...
Gronwall R, Brown MP.Para-aminohippuric acid (PAHA, 0.1 mg/min/kg of body weight) was infused IV into 2 mares, followed by concurrent IV infusion of PAHA and probenecid (0.075, 0.15, 0.25, or 0.35 mg of probenecid/min/kg). Probenecid infusion reduced the clearance of PAHA at serum probenecid concentrations greater than 55 micrograms/ml. At 12-hour intervals, probenecid (in 5 repeated doses - 50, 75, 100, or 200 mg/kg) was administered by gavage to 2 mares. Mean serum probenecid concentration was greater than 55 micrograms/ml for all dosages. At dosages less than 200 mg/kg, accumulation of probenecid in the serum w...
Evans DL, Rose RJ.Six Standardbred horses were used to evaluate the time course of pulmonary gas exchange, ventilation, heart rate (HR) and acid base balance during different intensities of constant-load treadmill exercise. Horses were exercised at approximately 50%, 75% and 100% maximum oxygen uptake (VO2 max) for 5 min and measurements taken every 30 s throughout exercise. At all work rates, the minute ventilation, respiratory frequency and tidal volume reached steady state values by 60 s of exercise. At 100% VO2 max, the oxygen consumption (VO2) increased to mean values of approximately 130 ml/kg.min, which ...
Geerken C, Doreau M, Boulot S.Urea, compared with deuterium oxide (D2O) as a reference, was used as a body marker to estimate body water volume in ten 2-month old nursing foals. Plasma urea clearance was regular over 10 h and the R2 of the disappearance curve was between 0.93 and 0.98. Mean urea space was about 4% lower than D2O space, but the standard deviation of the proportion of water in body weight was higher with urea (3.8%) than with D2O (1.6%). Calculated urea entry rate was 49 mg/h/kg LW0.75.
Toutain PL, Oukessou M, Autefage A, Alvinerie M.Using a specific high-performance liquid chromatographic technique, plasma hydrocortisone values were measured hourly in 6 horses and every 10 minutes in 4 horses over 24 hours. Both circadian and episodic variation was observed. The mean plasma hydrocortisone concentration was a maximum of 58.8 +/- 9.54 ng/ml at 9.19 +/- 0.59 hr and a minimum of 27.85 +/- 6.85 g/ml at 21.19 +/- 0.59 hr. The number of episodes of secretion was 10.0 +/- 1.41; the mean amplitude and duration of peak were 26.21 +/- 3.71 ng/ml and 105.25 +/- 21.24 min respectively.
Hansen TO, White NA, Kemp DT.Total parenteral nutrition was accomplished in 4 healthy adult horses. During the 10-day study, the horses were not permitted to ingest food or water. Body weight was maintained at 94% of initial values without clinical evidence of dehydration. Serum urea nitrogen and triacylglycerol concentrations decreased during the study, without other significant hematologic or biochemical changes. Horses adapted without problems to the routine of IV feeding and confinement. All horses were healthy at the conclusion of the study. It was concluded that intravenous feeding with a lipid-glucose-amino acid-el...
Jonckheere JA, Thienpont LM, De Leenheer AP, De Backer P, Debackere M, Belpaire FM.A method has been developed for quantification of bromhexine in plasma using gas chromatography mass spectrometry with selected ion monitoring. A deuterium labelled analogue was synthesized and used as the internal standard. To evaluate the gas chromatographic electron capture detection method described earlier, 23 plasma samples have been analysed by both techniques. Although a good correlation was shown, selected ion monitoring was superior to the electron capture detection method for levels below 3 ng ml-1. The mass spectrometric method has also been used to set up a pharmacokinetic study o...
Peters GJ, Oosterhof A, Veerkamp JH.1. Activity of uridine kinase was very low in ovine lymphocytes and in those of some pigs. Lymphocytes of other pigs showed a significantly higher activity of this enzyme. Activity of uridine kinase in lymphocytes of man, horse and cattle was intermediate. 2. Activity of uridine phosphorylase was higher than that of uridine kinase with lymphocytes of all species. 3. Activity of uridine kinase in equine lymphocytes increases at PHA-stimulation and also in porcine lymphocytes with a low activity at the start of the culture. Activity of uridine kinase decreased in porcine lymphocytes with a high ...
Delatour P, Garnier F, Maire R.After administration of the racemic drug, the stereoselective quantification of the enantiomers of free and conjugated carprofen was performed in human plasma and in plasma, urine and bile of dogs and horses. In humans, the plasma profile of free carprofen and its glucuronides is not stereoselective and the glucuronides excreted in urine are close to a racemate. In dogs and horses on the contrary, the R(-) enantiomer of the free drug is predominant in plasma, while urine and/or bile concentrations of the glucuronides are high in comparison to plasma with a strong selectivity for the S(+) enant...
Kerrigan LE, Thompson DL, Chapman AM, Oberhaus EL.Sympathoadrenal stimulation may perturb results of endocrine tests performed on fractious horses. Sedation may be beneficial; however, perturbation of results may preclude useful information. Four experiments were designed to 1) determine the effects of epinephrine on insulin response to glucose (IR2G), 2) assess the effects of detomidine (DET), alone or combined with butorphanol (DET/BUT), on IR2G and glucose response to insulin (GR2I), and 3) assess the effects of BUT alone on IR2G. In Experiment 1, mares were administered saline or epinephrine (5 μg/kg BW) immediately before infusion of gl...
Yamada M, Aramaki S, Okayasu T, Hosoe T, Kurosawa M, Kijima-Suda I, Saito K, Nakazawa H.Anabolic steroids with the 17alpha-methyl,17beta-hydroxyl group, which were developed as oral formulations for therapeutic purposes, have been abused in the field of human sports. These anabolic steroids are also used to enhance racing performance in racehorses. In humans, structurally related 17alpha-methyltestosterone (MTS) and mestanolone (MSL), which are anabolic steroids with the 17alpha-methyl,17beta-hydroxyl group, have metabolites in common. The purpose of this study was to determine metabolites common to these two steroids in horses, which may serve as readily available screening targ...
Schryver HF, Meakim DW, Lowe JE, Williams J, Soderholm LV, Hintz HF.The effect of level of protein intake on growth and calcium metabolism was studied in 24 foals. Starting at four months old, the foals were fed one of three diets containing all nutrients, with the exception of protein, at levels recommended by the United States National Research Council Subcommittee on Horse Nutrition for a 12 month period. The protein levels in the three diets were 9 per cent (low protein) 14 per cent (NRC recommended level) and 20 per cent (high protein). The foals fed the low protein diet were changed to the high protein diet after 140 days when they were nine months old. ...
KAMINSKI M, GAJOS E.TWENTY-THREE fresh and 28 frozen (1–11 years old) samples of horse sera, 62 frozen donkey sera (3–11 years old), 24 frozen mule sera (2–10 years old), and 1 frozen 2-year-old serum sample of a hinny (offspring of a she-ass by a stallion) were studied by starch- and agar-gel electrophoresis (starch gel: horizontal migration, discontinued buffer system; tris-citrate pH 8.7 and borate 0.3 M, pH 8.2; 2 V/cm for 14 h; 10 samples analysed simultaneously; 0.1 ml. serum mixed with soluble starch Merck; agar gel: 0.8 per cent agar in veronal buffer 0.025 M, pH 8.2; 4.5 V/cm; 2½ h; 10 samples on ...
Choi TLS, Wong JKY, Kwok WH, Curl P, Mechie S, Wan TSM.Methylstenbolone (2,17α-dimethyl-5α-androst-1-en-17β-ol-3-one) is a synthetic anabolic and androgenic steroid (AAS) sold as an oral 'nutritional supplement' under the brand names 'Ultradrol', 'M-Sten' and 'Methyl-Sten'. Like other AASs, methylstenbolone is a prohibited substance in both human and equine sports. This paper describes the studies of the in vitro and in vivo metabolism of methylstenbolone in horses using LC/HRMS, GC/MS and GC/MS/MS. Phase I in vitro metabolic study of methylstenbolone was performed using homogenised horse liver. Hydroxylation was the only biotransformation obse...
Sandler EA, Frisbie DD, McIlwraith CW.Previous in vitro pilot studies have defined a potentially beneficial effect of insulin-like growth factor-1 (IGF-1) and triamcinolone acetonide (TA) on interleukin-1 (IL-1)-conditioned equine cartilage. Furthermore, an optimal dose for IGF-1 treatment alone has been documented previously using the same test system as in the current project. Objective: To perform a dose titration of TA on IL-1-conditioned equine articular cartilage explants in the presence of an optimised IGF-1 dose, in order to optimise a triamcinolone concentration for use in combination with IGF-1 for future investigations....
Care AD.The mammalian fetus is maintained hypercalcaemic relative to its mother primarily by the action of a placental calcium pump located in the basal plasma membrane of the trophoblast. It is suggested that the activity of this pump is stimulated by a mid-molecular fragment of parathyroid hormone-related protein [PTHrP(38-94NH2)], produced in the placenta (and also in the parathyroid glands of fetal lambs and calves) as a result of post translational processing. In the sheep, calcitriol is an important determinant of fetal calcium homeostasis and it, too, stimulates the transport of calcium across ...
Davie A, Beavers R, Hargitaiová K, Denham J.This paper provides a comprehensive discussion on the physiological impacts of hypoxic training, its benefits to endurance performance, and a rationale for utilizing it to improve performance in the equine athlete. All exercise-induced training adaptations are governed by genetics. Exercise prescriptions can be tailored to elicit the desired physiological adaptations. Although the application of hypoxic stimuli on its own is not ideal to promote favorable molecular responses, exercise training under hypoxic conditions provides an optimal environment for maximizing physiological adaptations to ...
Scantamburlo G, Nofziger C, Paulmichl M, Vanoni S.Because of their importance as companion animals or as racehorses, horses can be treated with various drugs. Although it is known that drug withdrawal times can vary for each horse, pharmacogenetics for these animals has not been adequately studied and requires further development. Since is responsible for the metabolism of 25-30% of drugs in humans, including some used to treat horses, a study of the family in horses was conducted to define its genetic structure as well as its expression pattern in the liver. Unassigned: Genomic DNA extracted from venous blood and mRNA from fresh liver tiss...
Reißmann M, Rajavel A, Kokov ZA, Schmitt AO.RNA sequencing makes it possible to uncover genetic mechanisms that underlie certain performance traits. In order to gain a deeper insight into the genetic background and biological processes involved in endurance performance in horses, the changes in the gene expression profiles induced by endurance runs over long (70 km) and short (15 km) distances in the blood of Kabardian horses () were analyzed. For the long-distance runs, we identified 1484 up- and 691 downregulated genes, while after short-distance runs, only 13 up- and 8 downregulated genes (FC > |1.5|; < 0.05) were found. These...
Berghaus LJ, Cathcart J, Berghaus RD, Ryan C, Toribio RE, Hart KA.Rhodococcus equi (R. equi), a pneumonia-causing intracellular bacterium, results in significant morbidity and mortality in young foals, while healthy adult horses rarely develop disease. Survival and replication within alveolar macrophages (AMφ) are the hallmarks of R. equi's pathogenicity. The vitamin D receptor (VDR) and its ligand, the active vitamin D metabolite 1,25(OH)2D, are important in immune responses to intracellular bacteria. The vitamin D/VDR pathway regulates the downstream production of cytokines in infected human AMφ. The immunomodulatory role of the vitamin D/VDR pathway in ...
Kwak YB, Yoo HH, Yoon J.This study investigated the potential benefits of the administration of red ginseng (RG) on lipid metabolism and the profiles of individual free fatty acids (FFAs) in healthy horses. Eight healthy horses, raised under similar conditions, were randomly divided into two groups, each comprising four horses. The experimental group received powdered RG (600 mg/kg/day) mixed with a carrier, and the control group received only the carrier. The parameters associated with lipid metabolism and probable adverse effects were evaluated in both groups after 3 weeks. The computational molecular networkin...
Kruse CJ, Dieu M, Renaud B, François AC, Stern D, Demazy C, Burteau S, Boemer F, Art T, Renard P, Votion DM.Equine atypical myopathy (AM) is a severe environmental intoxication linked to the ingestion of protoxins contained in seeds and seedlings of the sycamore maple (Acer pseudoplatanus) in Europe. The toxic metabolites cause a frequently fatal rhabdomyolysis syndrome in grazing horses. Since these toxic metabolites can also be present in cograzing horses, it is still unclear as to why, in a similar environmental context, some horses show signs of AM, whereas others remain clinically healthy. Label-free proteomic analyses on the serum of 26 diseased AM, 23 cograzers, and 11 control horses were per...
Hormones and behaviorMarch 18, 2024
Volume 161 105526 doi: 10.1016/j.yhbeh.2024.105526
Granweiler J, Cristóbal-Azkarate J, Morton N, Palme R, Shultz S.In seasonal environments, maintaining a constant body temperature poses challenges for endotherms. Cold winters at high latitudes, with limited food availability, create opposing demands on metabolism: upregulation preserves body temperature but depletes energy reserves. Examining endocrine profiles, such as thyroid hormone triiodothyronine (T3) and glucocorticoids (GCs), proxies for changes in metabolic rate and acute stressors, offer insights into physiological trade-offs. We evaluated how environmental conditions and gestation impact on faecal hormone metabolites (fT3Ms and fGCMs) from late...
Zhang X, Geng A, Cao D, Dugarjaviin M. Horses are susceptible to oxidative stress during strenuous endurance exercise, leading to muscle fatigue and damage. Mulberry leaf flavonoids (MLFs) possess significant antioxidant properties. However, the antioxidant efficacy of MLFs can be influenced by the extraction process, and their impact on HO-induced oxidative stress in equine skeletal muscle satellite cells (ESMCs) remains unexplored. Our study employed three extraction methods to obtain MLFs: ultrasound-assisted extraction (CEP), purification with AB-8 macroporous resin (RP), and n-butanol extraction (NB-EP). We assessed the prot...
Ishimaru M, Tsuchiya T, Endo Y, Matsui A, Ohmura H, Murase H, Korosue K, Sato F, Taya K.Effects of different winter paddock management of Thoroughbred weanlings and yearlings in Hokkaido, Japan, which is extremely cold in winter, on physiological function, endocrine function and growth were investigated. They were divided into two groups; those kept outdoors for 22 hr in the paddock (22hr group) and those kept outdoors for 7 hr in daytime with walking exercise for 1 hr using the horse-walker (7hr +W group), and the changes in daily distance travelled, body temperature (BT), heart rate (HR), HR variability (HRV), endocrine function and growth parameters were compared between the t...
Laus F, Bazzano M, Spaterna A, Laghi L, Marchegiani A.Metabolomics can allow for the comprehensive identification of metabolites within biological systems, at given time points, in physiological and pathological conditions. In the last few years, metabolomic analysis has gained popularity both in human and in veterinary medicine, showing great potential for novel applications in clinical activity. The aim of applying metabolomics in clinical practice is understanding the mechanisms underlying pathological conditions and the influence of certain stimuli (i.e., drugs, nutrition, exercise) on body systems, in the attempt of identifying biomarkers th...
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...
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 ...
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...
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...
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...
Martano M, Power K, Cuccaro B, Razzuoli E, Maiolino P, Restucci B.The equine sarcoid is the most common skin neoplasia of fibroblastic origin in horses, characterized by an excessive accumulation of extracellular matrix produced by sarcoid fibroblasts under hypoxic condition. Neoplastic cells can adapt to hypoxia by using alternative energy sources, particularly those that arise from fatty acid oxidation (FAO). The Carnitine Palmitoyl Transferase 1A (CPT1A) belongs to Carnitine System (CS) and promotes the entrance of fatty acids into the mitochondria for β-oxidation. In this study, CPT1A expression was comparatively addressed in 25 equine sarcoids and 5 no...
