Analyze Diet

Topic:Energy Metabolism

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.
Variations in the fecal microbiota and their functions of Thoroughbred, Mongolian, and Hybrid horses.
Frontiers in veterinary science    July 28, 2022   Volume 9 920080 doi: 10.3389/fvets.2022.920080
Wen X, Luo S, Lv D, Jia C, Zhou X, Zhai Q, Xi L, Yang C.The horse gut is colonized by a rich and complex microbial community that has important roles in horse physiology, metabolism, nutrition, and immune functions. Fewer across-breed variations in horse gut microbial diversity have been illustrated. In this article, the gut microbiota of Thoroughbred, Mongolian, and Hybrid horses [first filial generation (F1) of Mongolian (maternal) and Thoroughbred (paternal)] were studied by second-generation high-throughput sequencing technology. Differences in gut microbiota composition and function between breeds were determined using diversity and functional...
ZOOMICS : comparative metabolomics of red blood cells from dogs, cows, horses and donkeys during refrigerated storage for up to 42 days.
Blood transfusion = Trasfusione del sangue    July 25, 2022   Volume 21, Issue 4 314-326 doi: 10.2450/2022.0118-22
Miglio A, Maslanka M, Di Tommaso M, Rocconi F, Nemkov T, Buehler PW, Antognoni MT, Spitalnik SL, D'Alessandro A.The use of omics technologies in human transfusion medicine has improved our understanding of the red blood cell (RBC) storage lesion(s). Despite significant progress towards understanding the storage lesion(s) of human RBCs, a comparison of basal and post-storage RBC metabolism across multiple species using omics technologies has not yet been reported, and is the focus of this study. Blood was collected in a standard bag system (CPD-SAG-Mannitol) from dogs (n=8), horses, bovines, and donkeys (n=6). All bags were stored at 4°C for up to 42 days (i.e., the end of the shelf life in Italian vete...
Evaluation of Two Equations for Prediction of Digestible Energy in Mixed Feeds and Diets for Horses.
Animals : an open access journal from MDPI    June 24, 2022   Volume 12, Issue 13 1628 doi: 10.3390/ani12131628
Martínez Marín AL, Valle E, Bergero D, Requena F, Forte C, Schiavone A.Several authors have developed equations for estimating digestible energy in horse feeds as an alternative to the inconveniences of in vivo digestibility assays. We aimed to evaluate two of such equations. A dataset was constructed from the literature with 32 mixed feeds and diets of known proximate composition, whose digestibility was measured in in vivo assays. Then, the digestible energy of the mixed feeds and diets was predicted with both equations from their proximate components. Precision, accuracy, reproducibility, bias, and decomposition of total error of predictions were determined. B...
Evaluation of Ultrasound Measurement of Subcutaneous Fat Thickness in Dairy Jennies during the Periparturient Period.
Animals : an open access journal from MDPI    May 26, 2022   Volume 12, Issue 11 doi: 10.3390/ani12111359
Nocera I, Bonelli F, Turini L, Madrigali A, Aliboni B, Sgorbini M.The body condition score (BCS) represents a practical but subjective method for assessing body fat reserves. Real time ultrasonography (RTU) has been proposed as an accurate method to objectively measure subcutaneous fat (SF) thickness and predict body fat reserves in cows, horses and donkeys. The aim of the present study was to describe RTU measures of SF thickness during periparturient period in jennies. The present prospective cohort study evaluated six dairy jennies. SF RTU were performed at 15 and 7 days before the presumptive delivery, and 2, 15 and 30 days after delivery. A portable ult...
Assessment of a full-scale solid-state anaerobic co-digestion: A multi-component substrate analysis by using ORWARE.
Waste management (New York, N.Y.)    May 10, 2022   Volume 146 36-43 doi: 10.1016/j.wasman.2022.04.042
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...
Effect of Milk Thistle (Silybum marianum) Seed Cakes by Horses Subjected to Physical Exertion.
Journal of equine veterinary science    March 19, 2022   Volume 113 103937 doi: 10.1016/j.jevs.2022.103937
Dockalova H, Baholet D, Batik A, Zeman L, Horky P.Milk thistle (Silybum marianum) provides several possible benefits for horses, namely anti-inflammatory, antioxidant effects, hepatoprotective, and neuroprotective effects. Silybin exerts also pronounced effects on energy metabolism, that could be useful for sport horses. The aim of this study is to evaluate the effect of milk thistle seed cakes (in the form of a granulated mixture with barley) on blood biochemical parameters (total protein, albumin, bilirubin, urea, creatinine, ALT, AST, ALP, GGT, LDH, the total cholesterol, HDL-cholesterol, LDL-cholesterol, TAG, BHB, NEFA, creatine kinase, l...
Selection signatures for heat tolerance in Brazilian horse breeds.
Molecular genetics and genomics : MGG    February 12, 2022   Volume 297, Issue 2 449-462 doi: 10.1007/s00438-022-01862-w
de Faria DA, do Prado Paim T, Dos Santos CA, Paiva SR, Nogueira MB, McManus C.Since domestication, horse breeds have adapted to their environments and differentiated from one another. This paper uses two methods to detect selection signatures in 23 horse breeds, eight of which are Brazilian (610 animals), both cold-blooded and warm-blooded, from temperate and tropical regions. These animals were genotyped using the GGP Equine BeadChip and we analysed the data by Principal Component Analysis (PCA). The samples were separated into groups based on their geographical area of origin and PCA results studied. The genomic regions under selection were detected by hapFLK and PCAd...
Humans have intestinal bacteria that degrade the plant cell walls in herbivores.
World journal of gastroenterology    December 30, 2021   Volume 27, Issue 45 7784-7791 doi: 10.3748/wjg.v27.i45.7784
Fujimori S.The cell walls of plants are mainly made of cellulose and contain a large number of calories. However, the main component, cellulose, is an indigestible plant fiber that is thought to be difficult for humans to use as energy. Herbivores acquire energy through the degradation of cell wall-derived dietary fiber by microorganisms in the digestive tract. Herbivores, especially horses, have a highly developed cecum and large intestine, and plants are fermented for their efficient use with the help of microorganisms. Humans also have an intestinal tract with a wide lumen on the proximal side of the ...
Composition and aptitude for cheese-making of milk from cows, buffaloes, goats, sheep, dromedary camels, and donkeys.
Journal of dairy science    December 23, 2021   Volume 105, Issue 3 2132-2152 doi: 10.3168/jds.2021-20961
Bittante G, Amalfitano N, Bergamaschi M, Patel N, Haddi ML, Benabid H, Pazzola M, Vacca GM, Tagliapietra F, Schiavon S.Bovines produce about 83% of the milk and dairy products consumed by humans worldwide, the rest represented by bubaline, caprine, ovine, camelid, and equine species, which are particularly important in areas of extensive pastoralism. Although milk is increasingly used for cheese production, the cheese-making efficiency of milk from the different species is not well known. This study compares the cheese-making ability of milk sampled from lactating females of the 6 dairy species in terms of milk composition, coagulation properties (using lactodynamography), curd-firming modeling, nutrients reco...
How Much Energy Vaquejada Horses Spend in a Field Simulation Test?
Animals : an open access journal from MDPI    November 30, 2021   Volume 11, Issue 12 doi: 10.3390/ani11123421
Coelho CS, Sodre TDRP, Sousa LN, Siqueira RF, Manso Filho HC, Aragona F, Fazio F.Vaquejada is a high-intensity and short-duration exercise in which helper horses (HH) are responsible to keep a bull running in a line while pull horses (PH) work to put the bull down after 100 m of running. The purpose of this study was to quantify and compare energy expenditures (EE), transport costs (COT) and metabolic energy requirements (Pmet) of horses used in Vaquejada. Thus, eight Quarter Horses, in randomly formed pairs, performed a vaquejada simulation test (VST), which consisted of three races on a sand track (130-150 m), with a 5-min interval between them. All horses used an integr...
Digestibility and nitrogen and water balance in horses fed rhizoma peanut hay.
Journal of animal science    October 12, 2021   Volume 99, Issue 11 doi: 10.1093/jas/skab284
Vasco ACCM, Brinkley-Bissinger KJ, Bobel JM, Dubeux JCB, Warren LK, Wickens CL.Rhizoma peanut (RP, Arachis glabrata) hay has the potential to meet horses' crude protein (CP) requirements with less nitrogen excretion than other legumes. This study aimed to evaluate nutrient intake, apparent digestibility, and nitrogen balance of RP "Florigraze" hay compared with alfalfa (ALF, Medicago sativa L. "Legendary XHD") and bermudagrass (BG, Cynodon dactylon L. "Coastal") hays when fed to maintenance horses at 2% body weight/d on a dry matter (DM) basis. We hypothesized that nutrient intake would be comparable between the legume hays and lesser for BG and that RP would result in r...
The enteroinsular axis during hospitalization in newborn foals.
Domestic animal endocrinology    September 16, 2021   Volume 78 106686 doi: 10.1016/j.domaniend.2021.106686
Rings LM, Kamr AM, Kinsella HM, Hostnik LD, Swink JM, Burns TA, Christie K, David JB, Toribio RE.The enteroinsular axis (EIA) is an energy regulatory system that modulates insulin secretion through the release of enteroendocrine factors (incretins). Despite the importance of energy homeostasis in the equine neonate, information on the EIA in hospitalized foals is lacking. The goals of this study were to measure serum insulin and plasma incretin (glucose-dependent insulinotropic polypeptide [GIP], glucagon-like peptide-1 [GLP-1] and glucagon-like peptide-2 [GLP-2]) concentrations, to determine the insulin and incretin association, as well as their link to disease severity and outcome in ho...
Straw as an Alternative to Grass Forage in Horses-Effects on Post-Prandial Metabolic Profile, Energy Intake, Behaviour and Gastric Ulceration.
Animals : an open access journal from MDPI    July 24, 2021   Volume 11, Issue 8 doi: 10.3390/ani11082197
Jansson A, Harris P, Davey SL, Luthersson N, Ragnarsson S, Ringmark S.Straw's low energy content means it is a roughage option for horses with low energy requirements. Previously, in a field study, straw was associated with an increased risk for gastric ulcers. This study evaluated the effect on gastric ulcers, metabolic profile and behaviour of replacing, in a forage-only ration, 50% of the daily allowance with wheat straw. Six equines were studied in a 2 × 21-day cross-over design. The control diet (CON: 100% grass forage) and the straw diet (S: 50% grass forage and 50% straw [DM basis]) were iso-energetic. Gastroscopy was performed prior to the study and on ...
Metabolic Profile Changes in Mangalarga Marchador Horses Subjected to A Hypercaloric Diet Evaluated by Proton NMR Spectroscopy.
Journal of equine veterinary science    June 11, 2021   Volume 103 103684 doi: 10.1016/j.jevs.2021.103684
Duarte PC, Ribeiro RM, Machado ART, Faleiros RR, Pimenta LPS, Filho JDS.The incidence of equine metabolic syndrome, a condition that results in endocrinopathic laminitis, is increasing worldwide. Although it is well known that the development of this syndrome depends on imbalances in energy metabolism and genetic traits, its pathophysiology remains unclear. Hydrogen nuclear magnetic resonance (H NMR) is a powerful tool used to compare metabolic profiles and to discriminate metabolites in living beings. The aim was to apply this technology to detect blood biomarkers candidates in horses that were previously demonstrated to developed metabolic changes when subjected...
Effective energy exploitation from horse manure combustion.
Waste management (New York, N.Y.)    May 15, 2021   Volume 128 243-250 doi: 10.1016/j.wasman.2021.04.035
Da Lio L, Castello P, Gianfelice G, Cavalli R, Canu P.We investigated the exploitation of horse manure for energy recovery by combustion. First, the impact of the waste origin and management (storage conditions) was evaluated in terms of elemental analysis, moisture content, heating value, and ash melting temperature. Besides some carbon loss over the time, horse manure origin and management policy do not impact its profitable exploitation by combustion. More relevant, the ignition tests disproved the current industrial opinion that combustion of manure alone is difficult, without the addition of auxiliary fuel, like wood shavings. It has been de...
Comparison of the Gut Microbiota of Jeju and Thoroughbred Horses in Korea.
Veterinary sciences    May 11, 2021   Volume 8, Issue 5 81 doi: 10.3390/vetsci8050081
Park T, Yoon J, Kim A, Unno T, Yun Y.(1) Background: The large intestine of horses is an anaerobic fermentative chamber filled with fibrolytic bacteria that play essential roles in digesting and absorbing nutrients for energy production. Although Jeju horses are a prominent local breed in Korea, few studies have investigated the gut microbiota of Jeju horses; (2) Methods: This study performed sequencing of V3 and V4 hypervariable regions of the partial 16S rRNA genes obtained from horse fecal samples and compared the gut microbiota between Jeju and Thoroughbred horses. Thirty and 24 fecal samples were obtained from Jeju and Thoro...
Low glucose and high pyruvate reduce the production of 2-oxoaldehydes, improving mitochondrial efficiency, redox regulation, and stallion sperm function†.
Biology of reproduction    April 18, 2021   Volume 105, Issue 2 519-532 doi: 10.1093/biolre/ioab073
Ortiz-Rodríguez JM, Martín-Cano FE, Gaitskell-Phillips GL, Silva A, Ortega-Ferrusola C, Gil MC, Peña FJ.Energy metabolism in spermatozoa is complex and involves the metabolism of carbohydrate fatty acids and amino acids. The ATP produced in the electron transport chain in the mitochondria appears to be crucial for both sperm motility and maintaining viability, whereas glycolytic enzymes in the flagella may contribute to ATP production to sustain motility and velocity. Stallion spermatozoa seemingly use diverse metabolic strategies, and in this regard, a study of the metabolic proteome showed that Gene Ontology terms and Reactome pathways related to pyruvate metabolism and the Krebs cycle were pr...
Rider Energy Expenditure During High Intensity Horse Activity.
Journal of equine veterinary science    April 8, 2021   Volume 102 103463 doi: 10.1016/j.jevs.2021.103463
O'Reilly C, Zoller J, Sigler D, Vogelsang M, Sawyer J, Fluckey J.Despite the fact that horseback riding is a popular sport, there is little information available on horseback riding as a physical activity. The objective of this experiment was to quantify energy expenditure of participants (n=20) during three riding tests: a 45min walk-trot-canter ride (WTC), a reining pattern ride and a cutting simulation ride while wearing a telemetric gas analyzer. Total energy expenditure (tEE), mean and peak metabolic equivalents of task (MET), heart rate (HR), respiratory frequency (RF), relative oxygen consumption (relVO2), and respiratory exchange ratio (RER) were as...
Understanding the Holobiont: Crosstalk Between Gut Microbiota and Mitochondria During Long Exercise in Horse.
Frontiers in molecular biosciences    April 8, 2021   Volume 8 656204 doi: 10.3389/fmolb.2021.656204
Mach N, Moroldo M, Rau A, Lecardonnel J, Le Moyec L, Robert C, Barrey E.Endurance exercise has a dramatic impact on the functionality of mitochondria and on the composition of the intestinal microbiome, but the mechanisms regulating the crosstalk between these two components are still largely unknown. Here, we sampled 20 elite horses before and after an endurance race and used blood transcriptome, blood metabolome and fecal microbiome to describe the gut-mitochondria crosstalk. A subset of mitochondria-related differentially expressed genes involved in pathways such as energy metabolism, oxidative stress and inflammation was discovered and then shown to be associa...
Nutritional Influences on Skeletal Muscle and Muscular Disease.
The Veterinary clinics of North America. Equine practice    April 7, 2021   Volume 37, Issue 1 139-175 doi: 10.1016/j.cveq.2020.12.005
Urschel KL, McKenzie EC.Skeletal muscle comprises 40% to 55% of mature body weight in horses, and its mass is determined largely by rates of muscle protein synthesis. In order to support exercise, appropriate energy sources are essential: glucose can support both anaerobic and aerobic exercise, whereas fat can only be metabolized aerobically. Following exercise, ingestion of nonfiber carbohydrates and protein can aid muscle growth and recovery. Muscle glycogen replenishment is slow in horses, regardless of dietary interventions. Several heritable muscle disorders, including type 1 and 2 polysaccharide storage myopath...
Nutritional Considerations when Dealing with an Underweight Adult or Senior Horse.
The Veterinary clinics of North America. Equine practice    April 7, 2021   Volume 37, Issue 1 89-110 doi: 10.1016/j.cveq.2020.12.003
Jarvis N, McKenzie HC.Weight loss occurs when the supply of energy is insufficient to meet the energy needs of an individual. The energy supply may be reduced by inadequate provision of feed, inadequate consumption, reduced digestion and absorption, or disruption in metabolic processing. Increased energy expenditure occurs with exercise and during cold temperatures, pregnancy, and lactation. Underlying clinical disease, particularly chronic inflammation, neoplasia, and protein-losing conditions, can cause weight loss or exacerbate existing weight loss. A methodical approach to weight-loss investigation and treatmen...
Variation of skeletal muscle ultrasound imaging intensity in horses after treadmill exercise: a proof of concept for glycogen content estimation.
BMC veterinary research    March 16, 2021   Volume 17, Issue 1 121 doi: 10.1186/s12917-021-02818-9
Glycogen in skeletal muscle is a major source of energy during exercise and an important determinant of endurance capacity, so that its measurement may provide a meaningful marker of athletes' preparation and a possible predictor of performance, both in humans and in equines. Gold standard of glycogen concentration measurement is the histochemical and biochemical analysis of biopsy-derived muscle tissue, an invasive and potentially injuring procedure. Recently, high-frequency ultrasound (US) technology is being exploited in human sports medicine to estimate muscle glycogen content. Therefore, ...
Equine maternal aging affects oocyte lipid content, metabolic function and developmental potential.
Reproduction (Cambridge, England)    February 5, 2021   Volume 161, Issue 4 399-409 doi: 10.1530/REP-20-0494
Catandi GD, Obeidat YM, Broeckling CD, Chen TW, Chicco AJ, Carnevale EM.Advanced maternal age is associated with a decline in fertility and oocyte quality. We used novel metabolic microsensors to assess effects of mare age on single oocyte and embryo metabolic function, which has not yet been similarly investigated in mammalian species. We hypothesized that equine maternal aging affects the metabolic function of oocytes and in vitro-produced early embryos, oocyte mitochondrial DNA (mtDNA) copy number, and relative abundance of metabolites involved in energy metabolism in oocytes and cumulus cells. Samples were collected from preovulatory follicles from young (≤1...
Glucagon, insulin, adrenocorticotropic hormone, and cortisol in response to carbohydrates and fasting in healthy neonatal foals.
Journal of veterinary internal medicine    January 7, 2021   Volume 35, Issue 1 550-559 doi: 10.1111/jvim.16024
Kinsella HM, Hostnik LD, Rings LM, Swink JM, Burns TA, Toribio RE.The endocrine pancreas and hypothalamic-pituitary-adrenal axis (HPAA) are central to energy homeostasis, but information on their dynamics in response to energy challenges in healthy newborn foals is lacking. Objective: To evaluate glucagon, insulin, ACTH, and cortisol response to fasting and carbohydrate administration in healthy foals. Methods: Twenty-two healthy Standardbred foals ≤4 days of age. Methods: Foals were assigned to fasted (n = 6), IV glucose (IVGT; n = 5), PO glucose (OGT; n = 5), and PO lactose (OLT; n = 6) test groups. Blood samples were collected frequently for 210 min...
Thermodynamics of Animal Locomotion.
Physical review letters    December 15, 2020   Volume 125, Issue 22 228102 doi: 10.1103/PhysRevLett.125.228102
Herbert E, Ouerdane H, Lecoeur P, Bels V, Goupil C.Muscles are biological actuators extensively studied in the frame of Hill's classic empirical model as isolated biomechanical entities, which hardly applies to a living organism subjected to physiological and environmental constraints. Here we elucidate the overarching principle of a living muscle action for locomotion, considering it from the thermodynamic viewpoint as an assembly of actuators (muscle units) connected in parallel, operating via chemical-to-mechanical energy conversion under mixed (potential and flux) boundary conditions. Introducing the energy cost of effort as the generaliza...
Prediction of the metabolisable energy content of forages and mixed diets for horses: validation and comparison of two evaluation systems.
Animal : an international journal of animal bioscience    December 14, 2020   Volume 15, Issue 2 100086 doi: 10.1016/j.animal.2020.100086
Martin-Rosset W, Andueza D, Vermorel M.The metabolisable energy (ME) content of feeds is a better estimate of their 'true' energy value than their digestible energy (DE) content, because ME takes account of the gross energy of methane (GEgas) and the gross energy of urine (GEurine) losses. The accuracy and precision of the Gesellschaft für Ernährungsphysiologie (GfE) and Institut National de la Recherche Agronomique (INRA) systems for predicting the DE and ME contents of diets for horses were compared using the results of a study comprising 15 mixed diets. The INRA system was more accurate than the GfE system for predicting DE, G...
Optimal speed in Thoroughbred horse racing.
PloS one    December 2, 2020   Volume 15, Issue 12 e0235024 doi: 10.1371/journal.pone.0235024
Mercier Q, Aftalion A.The objective of this work is to provide a mathematical analysis on how a Thoroughbred horse should regulate its speed over the course of a race to optimize performance. Because Thoroughbred horses are not capable of running the whole race at top speed, determining what pace to set and when to unleash the burst of speed is essential. Our model relies on mechanics, energetics (both aerobic and anaerobic) and motor control. It is a system of coupled ordinary differential equations on the velocity, the propulsive force and the anaerobic energy, that leads to an optimal control problem that we sol...
Concentrations of Circulating Irisin and Myostatin in Race and Endurace Purebred Arabian Horses-Preliminary Study.
Animals : an open access journal from MDPI    December 1, 2020   Volume 10, Issue 12 2268 doi: 10.3390/ani10122268
Kowalik S, Wiśniewska A, Kędzierski W, Janczarek I.Skeletal muscle is considered to be the largest endocrine organ determining the maintenance of energy homeostasis. Adaptive changes in skeletal muscles in response to physical exercise influence the production as well as secretion of myokines, which are bioactive factors that play a crucial role in energy expenditure processes. The aim of the study was to investigate the impact of two different types of exercise on the circulating level of two of these, myostatin and irisin, in trained horses. Twenty purebred Arabian horses were involved in the study: 10 three-year-old horses trained on the ra...
Variability of ACOX1 Gene Polymorphisms across Different Horse Breeds with Regard to Selection Pressure.
Animals : an open access journal from MDPI    November 27, 2020   Volume 10, Issue 12 2225 doi: 10.3390/ani10122225
Myćka G, Musiał AD, Stefaniuk-Szmukier M, Piórkowska K, Ropka-Molik K.The gene encodes peroxisomal acyl-coenzyme A oxidase 1, the first enzyme in the fatty acid β-oxidation pathway, which could be significant for organisms exposed to long periods of starvation and harsh living conditions. We hypothesized that variations within , revealed by RNA Sequencing (RNA-Seq), might be based on adaptation to living conditions and had resulted from selection pressure. There were five different horse breeds used in this study, representing various utility types: Arabian, Thoroughbred, Polish Konik, draft horses, and Hucul. The single-nucleotide polymorphism (SNP) located i...
The energy requirements of racehorses in training.
Translational animal science    November 3, 2020   Volume 4, Issue 4 txaa196 doi: 10.1093/tas/txaa196
Ebert M, Moore-Colyer MJS.The aim of this study was to estimate the energy requirements of Thoroughbred racehorses in active training for flat racing. Twenty-two Thoroughbred racehorses in England were measured over periods from 6 to 15 wk, which included periods of active race training and temporarily reduced training. Energy intake was determined by measuring daily feed consumption. Energy output was measured using heart rate monitors during 730 training sessions, relating heart rate (HR) to oxygen consumption (VO2) and converting VO2 to energy. Field maintenance requirements were calculated by deducting the marginal...