Energy metabolism in horses refers to the biochemical processes that convert nutrients into energy within the body, supporting various physiological functions. This process involves the breakdown of carbohydrates, fats, and proteins to produce adenosine triphosphate (ATP), the primary energy carrier in cells. Key metabolic pathways include glycolysis, the citric acid cycle, and oxidative phosphorylation. Energy metabolism is essential for maintaining muscle function, thermoregulation, and overall health in horses. Factors such as diet, exercise, and health status can influence these metabolic processes. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, regulation, and implications of energy metabolism in equine physiology.
Hinchcliff KW, McKeever KH, Muir WW, Sams RA.We theorized that furosemide-induced weight reduction would reduce the contribution of anaerobic metabolism to energy expenditure of horses during intense exertion. The effects of furosemide on accumulated O2 deficit and plasma lactate concentration of horses during high-intensity exercise were examined in a three-way balance randomized crossover study. Nine horses completed each of three trials: 1) a control (C) trial, 2) a furosemide-unloaded (FU) trial in which the horse received furosemide 4 h before running, and 3) a furosemide weight-loaded (FL) trial during which the horse received furo...
Gauvreau GM, Young SS, Staempfli H, McCutcheon LJ, Wilson BA, McDonell WN.A valved gas collection system for horses was validated, then used to examine the relationship between the respiratory exchange ratio (RER), and plasma and muscle lactate in exercising horses. Four healthy Standardbred horses were trained to breathe through the apparatus while exercising on a treadmill. Comparisons of arterial blood gas tensions were made at 3 work levels for each horse, without (control), and with the gas collection system present. At the highest work level, the arterial oxygen tension (PaO2) was significantly lower (P < 0.05), and the arterial carbon dioxide tension (PaCO2) ...
Kronfeld DS.Does dietary fat supplementation during conditioning improve athletic performance, especially in the heat? Fat adaptation has been used to increase energy density, decrease bowel bulk and faecal output and reduce health risks associated with hydrolysable carbohydrate overload. It may also reduce spontaneous activity and reactivity (excitability), increase fatty acid oxidation, reduce CO2 production and associated acidosis, enhance metabolic regulation of glycolysis, improve both aerobic and anaerobic performance and substantially reduce heat production. A thermochemical analysis of ATP generat...
Sticker LS, Thompson DL, Bunting LD, Fernandez JM.Two diets consisting of bermudagrass hay and a corn-cottonseed hull-based supplement were formulated to provide either 100% (control) or 50% (restricted) of the protein and energy requirements for maintenance for mature mares. Twelve light horse mares were fed the control diet for 7 d, and then at 0800 on d 0, six mares were switched to the restricted diet. All diets were fed as two equally sized meals at 0800 and 1600. At 0800 on d 7, mares receiving the restricted diet were switched back to the control diet. Relative to control mares, mares switched to the restricted diet had reduced plasma ...
Tyler CM, Hodgson DR, Rose RJ.The VO2(max) in racehorses is approximately double that of elite human athletes and the rate of increase in VO2 at the onset of high intensity exercise is much greater than in man. The kinetics of gas exchange are affected by a warm-up prior to exercise in humans, there being a greater aerobic contribution to high intensity exercise after warm-up. Our hypothesis was that a warm-up would increase aerobic energy delivery in racehorses during high intensity exercise. Thirteen fit Standardbred racehorses ran to fatigue at 115% of VO2(max) on a treadmill at 10% slope. Prior to acceleration, horses ...
Pearson RA, Lawrence PR, Smith AJ.Draught animal research carried out by scientists at the Centre for Topical Veterinary Medicine (CTVM) in Edinburgh and overseas is reviewed and the major findings are reported. The remit for the work has been to provide basic information on draught animals which can be applied by researchers and extension workers to their own geographic situations. Instrumentation is described which has been designed and manufactured to assist in the measurement of draught animal performance, particularly work output and energy consumption. Energy requirements of cattle, buffaloes and equids for work and ways...
Jones JH, Carlson GP.The metabolic power required for sustained exercise in the horse is proportional to running speed. Moderately fast speeds require substantial energy expenditure and result in the generation of a massive metabolic heat load. Quantitative estimates of energy expenditure and heat production of horses at various running speeds were developed using empirically derived data from treadmill studies. Total metabolic power represents the sum of aerobic power indicated by the rate of oxygen consumption and net anaerobic power indicated by the rate of plasma lactate accumulation. These data were applied t...
Nanua P, Waldron KJ.In this paper, the dynamics of quadruped trot, gallop, and bound will be examined using a simple model for the quadruped. The body of the quadruped is modeled as a uniform bar and the legs are modeled by massless springs. It will be shown that symmetry can be used to study the locomotion of this system. Using symmetry, a technique will be developed to obtain periodic solutions for each of the gaits of the quadruped model. These periodic solutions will be computed at various speeds. The energy levels will be compared for each of the gaits. The exchange of energy between its different forms will...
Porter RK, Brand MD.Resting O2 consumption of hepatocytes isolated from mammals ranging in mass from 20-g mice to 200-kg horses decreases with increasing body mass. The substrate oxidation system increases in activity with increasing body mass and mitochondrial proton leak and phosphorylation system decrease in activity, resulting in a higher mitochondrial membrane potential in hepatocytes from larger mammals. The absolute rates of O2 consumption due to nonmitochondrial processes, substrate oxidation, mitochondrial proton leak, and the phosphorylation system decrease with increasing body mass. These decreases are...
Sticker LS, Thompson DL, Fernandez JM, Bunting LD, DePew CL.Sixteen light horse mares were fed diets of bermudagrass hay and a corn/cottonseed hull-based supplement formulated to contain either 100% (control) or 50% (restricted) of the protein and(or) energy requirements for maintenance in a 2 x 2 factorial arrangement of treatments. Plasma IGF-I, prolactin, cortisol, triiodothyronine, and thyroxine were monitored for 33 d. On the 27th d, frequent blood samples were drawn throughout the day for the measurement of growth hormone (GH), and on the 29th d, an epinephrine challenge and an i.v. glucose tolerance test (IVGTT) were performed in the morning and...
Baba K, Kawamura T, Shibata M, Sohirad M, Kamiya A.The aim of this computer simulation study is to evaluate the efficiency of capillary networks in the skeletal muscle for oxygen (O2) delivery to tissue for all mammals. This was performed by: (1) employing Krogh's cylinder model for the capillary-tissue system and the minimum volume model for the vascular system, (2) allometrically assessing the muscle blood flow and O2 consumption rate (the main input data) in the resting and exercising states as power functions of body weight from the data reported for several mammals, and (3) calculating the cost-performance of the system from the ratio (ma...
Sticker LS, Thompson DL, Bunting LD, Fernandez JM, DePew CL.Sixteen light horse mares (8 to 9 yr of age; 457 to 579 kg BW) were fed Bermudagrass hay and a corn/cottonseed hull-based supplement formulated to contain either 100% (control) or 50% (restricted) of the protein and(or) energy requirements for maintenance in a 2 x 2 factorial arrangement of treatments. Daily measurements of intake, BW, and plasma hormones and metabolites were made for 33 d. Plasma glucose, insulin, NEFA, and urea N were measured in hourly samples drawn on d 27, and parallel with an i.v. glucose tolerance test (IVGTT) and epinephrine challenge on d 29. Energy restriction increa...
The Journal of nutritionDecember 1, 1994
Volume 124, Issue 12 Suppl 2723S-2729S doi: 10.1093/jn/124.suppl_12.2723S
Hintz HF.Some aspects of energy, protein and vitamin E nutrition of the performance horse are discussed. The amount, dietary source and time of ingestion of energy before exercise can influence performance. In 1989 the National Research Council (NRC) increased their estimates of energy required by racehorses. Recent studies indicate that the increase was reasonable. Many factors, however, can influence energy requirements. Therefore, the best measure would be body weight and composition of the horse. A proper balance of soluble carbohydrate, fiber, fat and protein is essential. Some guidelines are pres...
Mueller PJ, Jones MT, Rawson RE, van Soest PJ, Hintz HF.Oxygen consumption (VO2) and concentration of venous blood metabolites were measured in donkeys trained to run and to pull loads on a treadmill. VO2 in two donkeys running at maximal speed on a 9.8% slope was 110 +/- 2 ml.min-1.kg-1, approximately 22 times preexercise VO2. Average heart rate at maximal VO2 (VO2max) was 223 +/- 2 beats/min, five times the preexercise heart rate. Blood lactate increased 14-fold, and blood glucose did not change (P > 0.05). Animals running up a 4% incline and incremental draft loading of five donkeys walking on the level were also studied. The total energy cost o...
Ramaswamy NS.In fifty developing countries, which contain half of the total human population of the world, there is a heavy dependence on draught animals as an energy source. These animals are used for agriculture operations in 52% of cultivated areas of the world, as well as for hauling 25 million carts. This situation is likely to continue for at least another fifty years. The work performed annually by these draught animals would require 20 million tons of petroleum, valued at US$6 billion, if it were performed by motorized vehicles. The poor working conditions of these animals often adversely affect th...
Hintz HF, Cymbaluk NF.The horse was domesticated around 2500 BC and has been used for work, pleasure, and companionship since that time. However, the percentage of time devoted to these endeavors has changed greatly. The number of horses in the US peaked at more than 26 million in 1918. Thereafter, the increasing use of the internal combustion engine caused a steady decline in the number of horses. By 1960, the US Department of Agriculture (USDA) estimated that there were only about 3 million horses in the US. In the 1960s, however, the number of...
Vittur F, Grandolfo M, Fragonas E, Godeas C, Paoletti S, Pollesello P, Kvam BJ, Ruzzier F, Starc T, Mozrzymas JW.Some aspects of the physiology of chondrocytes from horse articular cartilage were studied, since this animal model can be helpful in understanding arthritic processes. The replicative ability of articular chondrocytes, measured by the incorporation of [3H]thymidine, and their capacity of proteoglycan production, evaluated from the incorporation of [35S] sulfate, are very low. In addition, these cells do not differentiate in vitro as shown by the constant specific activity of alkaline phosphatase measured at different times in culture. Two types of potassium channels were identified by patch c...
Butler PJ, Woakes AJ, Anderson LS, Roberts CA, Marlin DJ.The purpose of this study was to test the hypothesis that locomotor-respiratory coupling in horses may provide a basis for the appropriate matching of lung ventilation to running speed and metabolic power. This was achieved by determining the effect on respiratory frequency and tidal volume in thoroughbred horses of changing running speed while maintaining a constant metabolic demand by also varying the incline of the treadmill. This procedure was performed at three different speeds at two different levels of metabolic rate. It appears that, in response to metabolic demands which are not direc...
Southwood LL, Evans DL, Bryden WL, Rose RJ.Twenty-five Thoroughbred (TB) and 25 Standardbred (SB) stables were visited to determine their feeding practices. The ingredients of the main feed of the day for a mature gelding of average size in full training were weighted at each stable. Nutrient content of diets was calculated using published data for the individual ingredients. Results are expressed as mean +/- sd. The estimated body weight of TB horses was 493 +/- 34 kg and 437 +/- 32 kg for SB horses. There was considerable variation in diet composition and nutrient intake between stables. The TB trainers fed 11.0 +/- 2.4 kg and SB tra...
Burlacu GH, Voicu D, Voicu I, Nicolae M, Petrache E, Georgescu GH, Balan S.The present study focused on energy and protein metabolism in pregnant and lactating mares, including the suckling and weaned growing horses, in order to determine feed availability, as also the energy and protein requirements. The authors found that the feeding diets, consisting of alfalfa hay, oats and compounds, had different availability values in terms of energy and protein, according to animal physiological conditions and age. Thus, the pregnant mares utilized the metabolizable energy (ME) and digestible crude protein (DCP) intake in average proportions of 64.5 +/- 3.2%, 54.6 +/- 3.0%, r...
Jones JH, Lindstedt SL.Body size fundamentally affects maximal locomotor performance in mammals. Comparisons of performances of different-sized animals yield different results if made using relative, rather than absolute scales. Absolute speed may be a reasonable way to evaluate the locomotor performance of an animal that must escape predators in real time. However, comparisons of metabolic power in animals of different size can only be made meaningfully on a mass-specific basis. Numerous factors associated with the mechanics, energetics, and storage of elastic energy during locomotion change with body size, which r...
Doreau M, Boulot S, Bauchart D, Barlet JP, Martin-Rosset W.Voluntary food intake, milk yield and composition, and blood metabolites were measured during the first 2 mo of lactation in draft broodmares fed diets containing either 95% hay and 5% concentrates (Diet F) or 50% hay and 50% concentrates (Diet C). Voluntary food intake was higher for mares fed Diet C than for those fed Diet F (22.9 vs. 21.4 kg dry matter in wk 4). Both diets, especially Diet C, were eaten in amounts exceeding the energy requirements. Daily milk yield in wk 4 was 26.4 kg and 23.4 kg for mares fed Diets C and F, respectively. Milk fat and protein concentrations were higher (P l...
Gutiérrez Rincón JA, Vives Turcó J, Muro Martínez I, Casas Vaqué I.The three main Olympic horse riding disciplines are dressage, jumping, and three-day eventing (including dressage, cross country and jumping). In the jumping discipline (obstacle race), the 'team' (horse rider) is judged under the different conditions that might take place in a varied run. The horse is expected to show power and ability; the rider must show riding skill and good physical condition. However, the different conditions encountered by the rider during competition (duration of event, continuous isometric working level, especially in the inferior trunk, lead us to consider the need f...
Cí·¯ord D, Woodhead A, Muirhead R.The objective was to evaluate the nutritive value of short-cutting cycle, high temperature-dried (SCCHTD) alfalfa compared to timothy hay. This was achieved by carrying out 4 x 4 Latin Square digestibility trial using 4 Thoroughbred (one three-quarter Thoroughbred) horses (mean liveweight, 531 kg). The four dietary treatments were 0AA (timothy hay only), 33AA (0.33 alfalfa: 0.67 timothy hay), 67AA (0.67 alfalfa: 0.33 timothy hay) and 100AA (alfalfa only). Digestibility data were obtained by using acid-insoluble ash to estimate apparent digestibility coefficients of nutrients. Rate of passage o...
Zimmerman NI, Wickler SJ, Rodiek AV, Hower MA.Four Arabian geldings were used in a randomized, repeated measure design to study the effect of two different diets on plasma free fatty acids at rest and during exercise. On each of four sampling days, two horses were fed one of two isoenergetic diets, either 100% corn or 100% alfalfa, at 22% of their estimated daily energy requirement. Two hours after the consumption of the diet, each horse participated in a submaximal standard exercise test consisting of three consecutive 10-min runs of increasing intensity at heart rates of 132, 140 and 147 beats/min, respectively. There were no significan...
Heinrich B.This research article corrects a common misconception about the energy metabolism in horses during short sprinting and long-distance running events, emphasizing that short sprints are primarily powered by anaerobic activity, […]
The Journal of nutritionSeptember 1, 1991
Volume 121, Issue 9 1462-1469 doi: 10.1093/jn/121.9.1462
Miller-Graber PA, Lawrence LM, Foreman JH, Bump KD, Fisher MG, Kurcz EV.Six conditioned Quarter Horse mares were used in a crossover design to assess the effect of the dietary protein level on intramuscular and hepatic glycogen and lactate, oxygen uptake and blood lactate, pyruvate and free fatty acids. After a 2-wk adaptation period to either a 9.0% (control) or an 18.5% crude protein diet, each horse performed an exercise test. The horses were exercised for 15 min on an 11% grade treadmill at 4.5 m/sec. The exercise test was performed 3-4 h after a meal. Venous, arterial and mixed-venous blood samples were taken simultaneously at rest and during exercise. Muscle...
Zentek J.In this case report on myopathies in 6 saddle-horses, a combined dietary vitamin E and selenium deficiency is presumed. Other disorders, such as exertional myopathy ("Monday morning disease") due to excessive energy intake or ionophore intoxication could be excluded by calculating the energy supply or by a simple colour test. The selenium requirement of horses is estimated to 0.1-0.2 mg/kg dry matter (Meyer 1986). If natural feed compounds are low in selenium, adequate amounts of this trace element can be supplied by means of supplemental feeds, sodium selenite (20 mg/500 kg BW/week) or bruise...
Doreau M, Martin-Rosset W, Barlet JP.In an experiment comparing pregnant then lactating mares with dry non-pregnant mares, the changes in plasma components were studied as indicators of the metabolic utilization of energy (glucose, non-esterified fatty acids, beta-hydroxybutyrate), nitrogen (urea, proteins) or minerals (calcium, phosphorus, magnesium). The mares were fed daily 2 kg concentrate and hay ad libitum. Beta-hydroxybutyrate, magnesium and to a lesser extent glucose were the only constituents whose levels were affected within the period starting one month before and ending one month after foaling. The increase in food in...
Hallebeek JM, Beynen AC.A fat-free liquid diet was formulated to be administered by nasogastric tube as therapy for hyperlipaemia in ponies. The liquid diet provided energy, protein, minerals, trace elements, and vitamins in accordance with the requirements of ponies. As sole source of nutrition, the liquid diet fully counteracted fasting-induced hyperlipaemia in two healthy ponies. The liquid diet was also used in hyperlipaemic patients, but only in combination with conventional therapy, consisting of intravenous administration of glucose, insulin, and heparin. Although no patients were treated with the liquid diet ...
Jensen RB, Kyrstein TD, Junghans P, Tauson AH.Energy expenditure (EE) can be estimated based on respiratory gas exchange measurements, traditionally done in respiration chambers by indirect calorimetry (IC). However, the (13)C-bicarbonate technique ((13)C-BT) might be an alternative minimal invasive method for estimation of CO(2) production and EE in the field. In this study, four Shetland ponies were used to explore the effect of feeding on CO(2) production and EE measured simultaneously by IC and (13)C-BT. The ponies were individually housed in respiration chambers and received either a single oral or intravenous (IV) bolus dose of (13)...
Filipović N, Stojević Z, Prvanović N.The changes in blood serum fructosamine concentrations as indicators of glycaemia during a longer period of time were investigated in mares during late pregnancy and early lactation, as well as their relationship to the changes in the concentration of biochemical indicators of energetic status. The samples were taken from eleven mares on 60 +/- 10 and 20 +/- 10 days before foaling, and 20 +/- 10 and 60 +/- 10 days after foaling. Concentrations of serum fructosamine, non-esterified fatty acids and triglycerides were higher during late pregnancy (from P < 0.05 to P < 0.0005), while the con...
Gauvreau GM, Young SS, Staempfli H, McCutcheon LJ, Wilson BA, McDonell WN.A valved gas collection system for horses was validated, then used to examine the relationship between the respiratory exchange ratio (RER), and plasma and muscle lactate in exercising horses. Four healthy Standardbred horses were trained to breathe through the apparatus while exercising on a treadmill. Comparisons of arterial blood gas tensions were made at 3 work levels for each horse, without (control), and with the gas collection system present. At the highest work level, the arterial oxygen tension (PaO2) was significantly lower (P < 0.05), and the arterial carbon dioxide tension (PaCO2) ...
Moore AB, Roesel OF, Fessler JF, Bottoms GD.The value of naloxone (1 mg/kg of body weight/hr for 4 hrs), a beta-endorphin antagonist, was assessed in the management of endotoxin-induced shock in ponies. Three groups of 5 ponies each were used: controls, ponies given Escherichia coli endotoxin put untreated, and ponies given endotoxin and then treated with naloxone. Endotoxin-induced changes in hemodynamics, blood chemical values, regional blood flow, plasma enzymes, and energy supplies were measured at selected times during the first 6 hours after endotoxin was given. There was no evidence that beta-endorphins released during shock were...
Doreau M, Martin-Rosset W.Uraemia variations in the heavy breed mare were studied in different situations. A study with 35 mares during an entire grazing season was conducted. The mean uraemia varied between 48.5 and 67.5 mg/100 ml plasma, with season and type of grass. The highest values were found with first-cycle pasture grass. Uraemia was lower with winter diets: 28.6 to 36.0 mg/100 ml. A study using 15 mares fed isonitrogenous diets based on hay or straw, and concentrates offered two different levels, between two months before and 8 days after foaling, showed that the physiological stage had a very moderate effect...
Hallebeek JM, van Doorn DA, Beynen AC.In horses that exercise intensively (for example, event horses in training) the intake and energy requirements were compared on the basis of a diet record and estimates of energy required for exercise. Daily net energy intake over a 7 days period was on average 30% (n = 15) higher than the net energy requirement. Since the horses had a constant body weight, and thus were in energy balance, the energy intake was overestimated and/or the energy requirement was underestimated. The intake of digestible protein was 92% higher than the protein requirement. This study illustrates the problems concern...
Geddes LA, Bourland JD, Tacker WA.The threshold energy and current required for ventricular defibrillation was determined in dogs ranging in weight from 6.4 to 38 kg and in ponies ranging in weight from 40 to 101 kg. Trapezoidal waves, 10 ms in duration, with 10%, 50%, 70%, and 90% tilt were applied to transchest electrodes. For all values of tilt, the energy and current required increased with body weight. The energy dose (joules per kilogram of body weight) was higher for the heavier animals, whereas the current dose (peak amperes per kilogram of body weight) was essentially the same for dogs and ponies. In both species and ...
Carlos-Pinedo S, Wang Z.Long-term sustainable biogas production requires different raw material alternatives, especially when reducing the most desirable organic substrate, food waste, which has been set as a goal in the 2030 Agenda. In Sweden, horse manure (HM) is generated in large quantities, and due to its physical and chemical characteristics, it has the potential to be used as a raw material to produce biogas through anaerobic digestion (AD). In order to investigate the challenges that HM digestion can impose in terms of methane yield and/or digestate quality, the modified ORganic WAste REsearch (ORWARE) AD mod...
DeBoer M, Konop A, Fisher B, Martinson K.Thermoregulation is an energy-expensive process, which can be mitigated by blanketing horses in cold climates, potentially preventing weight loss or leading to decreased feed intake. The objective of this study was to evaluate feed intake, body weight (BW), and body condition scores (BCSs) in blanketed and nonblanketed horses. In October 2019, 16 mature adult horses were blocked by breed and BCS and randomly assigned to a blanketed (n = 8) or nonblanketed (n = 8) treatment; blankets were placed. Data were collected in December 2019 and January 2020 in River Falls, Wisconsin. During the study...
Ralston SL.A survey was taken of dietary management and training schedules of 54 horses competing in two 160 km endurance races. A total of 52 owners, representing 54 horses, responded to a questionnaire distributed prior to the races. Diet and training schedules were compared between horses that successfully completed the races and those that were eliminated for metabolic reasons. Horses that completed the races were 11.5 +/- 4 years old, weighed 429 +/- 4.5 kg and were ridden 61 +/- 32 km a week when training. Feed intake was reported as "free choice hay or pasture" by 34 of the respondents. Dry matter...
Fortier J, Deley G, Julliand V.This study aimed at quantifying energy expenditure during 4 specific training exercises, that is, promenade, jogging, parcours, and interval exercises, using field measurements of oxygen consumption and heart rate in trotters. Six animals performed 2 preliminary tests to determine their individual maximum velocity and to establish their individual oxygen consumption/heart rate relationship from an incremental test. Then, they undertook each of the 4 specific exercises separated by 1 wk to avoid fatigue. The intensity of the 4 exercises was expressed in percent of individual maximum velocity as...
Cymbaluk NF, Christison GI, Leach DH.Eighteen Quarter Horse and Paint weanling colts were assigned to two treatments, either limit or ad libitum feeding. Nutrient digestibilities of diets were evaluated between 6 and 12 mo, 12 and 18 mo and 18 and 24 mo of age. From 6 to 12 mo, energy digestibility (64 to 68%) was unaffected by feed intake level. Ad libitum-fed horses had energy digestibilities 9 to 10% greater (P less than .05) than limit-fed horses between 12 and 24 mo of age, but adjustment for DM intake removed these differences. Limit-fed, mature ponies used dietary energy similarly to growing horses from 6 to 18 mo of age, ...
Martin-Rosset W, Andueza D, Vermorel M.The accuracy and precision of the National Research Council (NRC), Gesellschaft für Ernährungsphysiologie (GfE) and Institut National de la Recherche Agronomique (INRA) systems for predicting the digestible energy (DE) value of hays were determined from the results of 15 digestibility trials with natural grassland hays and 9 digestibility trials with lucerne hays that all met strict experimental and a tight corpus of methods. The hays were harvested in the temperate zone. They covered broad ranges of chemical composition and DE value. The INRA system was more accurate than the other two syst...
Burlacu GH, Voicu D, Voicu I, Nicolae M, Petrache E, Georgescu GH, Balan S.The present study focused on energy and protein metabolism in pregnant and lactating mares, including the suckling and weaned growing horses, in order to determine feed availability, as also the energy and protein requirements. The authors found that the feeding diets, consisting of alfalfa hay, oats and compounds, had different availability values in terms of energy and protein, according to animal physiological conditions and age. Thus, the pregnant mares utilized the metabolizable energy (ME) and digestible crude protein (DCP) intake in average proportions of 64.5 +/- 3.2%, 54.6 +/- 3.0%, r...
Buff PR, Johnson PJ, Wiedmeyer CE, Ganjam VK, Messer Iv NT, Keisler DH.Horses fed beyond their nutritional requirement and that are physically inactive will develop obesity, which is often accompanied by insulin resistance and heightened risk of laminitis. The use of pharmacologic agents in combination with nutritional restriction may promote weight loss in obese horses unable to exercise because of laminitic pain. This study shows that reducing feed intake of brome grass hay to 75% of ad libitum intake in obese pony mares reduces body weight without induced exercise. Additional supplementation of ractopamine hydrochloride for 6 weeks resulted in a tendency for i...
Medina-Torres CE, Underwood C, Pollitt CC, Castro-Olivera EM, Hodson MP, Richardson DW, van Eps AW.A suitable method for evaluating lamellar perfusion changes and their metabolic consequences is currently lacking. Objective: To examine perfusion changes in lamellar tissue using serial microdialysis measurements of urea clearance and energy metabolites. Methods: Randomised, controlled (within subject) experimental trial. Methods: Nine Standardbred horses were instrumented with microdialysis probes in the foot lamellar tissue and skin (over the tail base). Urea (20 mmol/l) was added to the perfusate and its clearance was used to estimate local perfusion. Samples were collected every 15 min fo...
Mack JK, Remler HP, Senckenberg E, Kienzle E.This study investigated the energy requirements of Warmblood foals with a change of the stud at weaning. Methods: Nine colts purchased at weaning participated in the study aged approximately 6 months to 1 year. They were transported to the stud by their breeders either having been separated from their dams in their home stable or upon arrival at the stud. The foals were offered a late first cut of haylage, oats and foal starter feed. To ensure individual feeding of concentrates, the foals were tethered twice daily. The total combined haylage intake of all foals per day was recorded. Individu...
The Journal of nutritionSeptember 1, 1991
Volume 121, Issue 9 1462-1469 doi: 10.1093/jn/121.9.1462
Miller-Graber PA, Lawrence LM, Foreman JH, Bump KD, Fisher MG, Kurcz EV.Six conditioned Quarter Horse mares were used in a crossover design to assess the effect of the dietary protein level on intramuscular and hepatic glycogen and lactate, oxygen uptake and blood lactate, pyruvate and free fatty acids. After a 2-wk adaptation period to either a 9.0% (control) or an 18.5% crude protein diet, each horse performed an exercise test. The horses were exercised for 15 min on an 11% grade treadmill at 4.5 m/sec. The exercise test was performed 3-4 h after a meal. Venous, arterial and mixed-venous blood samples were taken simultaneously at rest and during exercise. Muscle...
Weyenberg SV, Hesta M, Buyse J, Papadopoulos GA, Janssens GP.To determine whether plasma leptin concentrations and glucose tolerance are affected by changes in energy balance, nine healthy Shetland ponies were fed at 140% followed by 75% of their maintenance requirements for 13 days in each of the two periods. Bodyweight was recorded every three days. Blood samples were taken every two days and analysed for leptin and cortisol. An oral glucose tolerance test was performed on day 7 of each period. Serial blood samples were analysed for glucose and insulin. Although bodyweight was not affected, plasma leptin concentrations increased (P<0.001) initially...
Ott EA, Asquith RL.Three experiments using 63 Thoroughbred and Quarter Horse yearlings were conducted to evaluate the influence of level of feeding, and protein and calculated energy content of pelleted concentrates on growth and bone development. Animals were housed in drylot paddocks and individually fed concentrates twice daily. Coastal bermudagrass (Cynodon dyctylon) hay was group-fed. Yearlings offered a corn-based concentrate (3.56 Mcal digestible energy [DE]/kg) consumed levels of dry matter similar to yearlings fed a mixed-grain concentrate (3.32 Mcal DE/kg but consumed slightly more digestible energy. N...
Jansen WL, van Alphen M, Berghout M, Everts H, Beynen AC.The ratio of calculated net energy intake (NEi) to calculate net energy requirement (NEr) might serve as an indicator of the efficiency of dietary energy utilization. The ratio was determined for 93 horses and ponies from 10 riding schools. For each animal with an assumed constant body weight, energy intake and energy requirements were assessed. On average, the estimated NEi was 14% greater than NEr. There was a significant, negative association between crude fibre intake and the NEi: NEr ratio. Earlier work indicated that extra fat intake may lead to over estimation of the calculated energy v...
Ekici S, Ozmen O.The active roles of microribonucleic acids (miRNAs) in gene regulation have made miRNAs a key point for the scientific world in the study of physiological processes. Although saliva includes the largest number of miRNAs, there is no miRNA study in saliva on horses has been found. Our study is the first study on miRNAs isolation from saliva in horses. In the present study, saliva was studied in Arabian racehorses to better understand the molecular mechanisms of expression levels that are effective in lipid metabolism of miRNAs and their target genes during the race. Identification of lipid meta...
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...
Turcott-White SK, Nielsen BD, Robison CI, Skelly CD, Rosenstein DS, Pritchard A, Herdt T.The objective of this study was to compare the feed intake and the apparent digestibilities of three different diets varying in concentrate-to-roughage ratios in weanling horses (n = 24) at 5 and 8 months of age. Horses were stratified by breed, gender, birth date and body weight and assigned to one of three dietary treatments containing the following concentrate-to-roughage ratios on an as-fed basis: 70:30 (High Con), 50:50 (Equal) and 30:70 (Low Con). All horses were fed their respective diets for a 10-day adaptation period and a 4-day collection period at 5 and 8 months. There were no d...
Baragli P, Ducci M, Gatta D, Gazzano A, Sighieri C.Catecholamines (CAT) play an important role in modulating the response to exercise. But the kinetics of CAT changes during exercise are difficult to study due to their short biological half-life. Objective: Learning about variations in plasma CAT levels during training could furnish new information regarding sweating, redistribution of blood flow and energy metabolism. Methods: Four untrained Standardbreds, adapted to treadmill work, were used to determine the influence of training on plasma adrenaline (A) and noradrenaline (NA) kinetics. Horses underwent a standardised exercise test (SET) on ...
Powell D, Lawrence LM, Brewster-Barnes T, Fitzgerald B, Warren LK, Rokuroda S, Parker A, Crum A.Eight Thoroughbred horses were used to determine the effects of long-term calorie restriction and diet composition on serum T4 and T3 concentrations and metabolic responses with exercise. Horses were randomly assigned to 2 treatment groups (n = 4): Group 1, horses were fed a calorie-restricted diet designed to have 70% of the calories from the roughage source (RHR); Group 2, horses were fed a calorie-restricted diet designed to have 70% of the calories from the concentrate source (RHC). Horses then completed 2 step-wise exercise tests; one following a 12 h fast and one 2 h after a meal of 2 kg...
Thompson KN, Jackson SG, Baker JP.Effects of high dietary levels of energy, protein and Ca and deficient levels of Ca on skeletal growth and development in the equine were studied in two experiments. The weanlings were fed grain-based diets. In Exp. 1, Group 1 (Ctl) received all nutrients at NRC recommended levels for growth; Group 2 (HE) received 150% of their digestible energy (DE) requirement; Group 3 (LC) received 150% of DE and 35% of Ca requirements. In Exp. 2, Group 1 (Ctl) again received all nutrients at NRC recommended levels for growth; Group 2 (HEP) received 150% of DE and 275% of CP requirements; Group 3 (HEPC) rec...
