Nutrition in horses encompasses the study of dietary requirements and feeding practices that support equine health, growth, and performance. It involves the analysis of nutrients such as carbohydrates, proteins, fats, vitamins, and minerals, and their roles in equine physiology. Proper nutrition is essential for maintaining optimal body condition, supporting metabolic processes, and preventing dietary-related disorders. Research in this field examines the nutritional needs of horses at different life stages and activity levels, as well as the effects of various feed types and supplements. This page compiles peer-reviewed research studies and scholarly articles that explore the composition, digestion, and impact of different dietary components on equine health and performance.
Contri A, De Amicis I, Molinari A, Faustini M, Gramenzi A, Robbe D, Carluccio A.In this study, the effect of dietary supplementation of organic selenium, vitamin E, and zinc on raw semen characteristics was evaluated. Ten stallions with normal fertility were divided into two groups: a control group (CG), in which standard diet was provided, and a treated group (TG), in which the standard diet was supplemented with 1500 mg of α-tocopherol acetate, 360 mg of zinc, and 2.5 mg of organic selenium on a daily basis. Semen parameters on fresh semen were evaluated three times in all stallions before antioxidant supplementation (T0) and 30 (T1), 60 (T2), and 90 (T3) d after suppl...
Urschel KL, Escobar J, McCutcheon LJ, Geor RJ.To determine the effect of refeeding following an 18-hour period of feed withholding on the phosphorylation of translation initiation factors in the skeletal muscle of mature horses. Methods: 8 adult horses. Methods: Following an 18-hour period of feed withholding, horses either continued to have feed withheld (postabsorptive state) or were fed 2 g/kg of a high-protein feed (33% crude protein) at time 0 and 30 minutes (postprandial state). Blood samples were taken throughout the experimental period. At 90 minutes, a biopsy specimen was taken from the middle gluteal muscle to measure the phosph...
Wilsher S, Allen WR.An opportunity to monitor equine chorionic gonadotrophin (eCG) production during 61 pregnancies in 25 Thoroughbred mares mated to the same Thoroughbred stallion was utilised in order to further knowledge regarding factors involved in the production of this hormone. Objective: To examine the effects of maternal body condition, exercise and parity on eCG production. Methods: In the first experiment, maiden mares were fed either a moderate (n = 9) or an excessive (n = 10) food intake throughout gestation. In the second experiment, 5 mares were exercised daily during pregnancy and eCG production r...
Ryan PL, Christiansen DL, Hopper RM, Walters FK, Moulton K, Curbelo J, Greene JM, Willard ST.Uterine and placental infections are the leading cause of abortion, stillbirth, and preterm delivery in the mare. Whereas uterine and placental infections in women have been studied extensively, a comprehensive examination of the pathogenic processes leading to this unsatisfactory pregnancy outcome in the mare has yet to be completed. Most information in the literature relating to late-term pregnancy loss in mares is based on retrospective studies of clinical cases submitted for necropsy. Here we report the development and application of a novel approach, whereby transgenically modified bacter...
Kaukinen H, Aspegrén J, Hyyppä S, Tamm L, Salonen JS.The objective of the study was to determine the absorption, bioavailability and sedative effect of detomidine administered to horses as an oromucosal gel compared to intravenous and intramuscular administration of detomidine injectable solution. The study was open and randomized, with three sequences crossover design. Nine healthy horses were given 40 μg/kg detomidine intravenously, intramuscularly or administered under the tongue with a 7-day wash-out period between treatments. Blood samples were collected before and after drug administration for the measurement of detomidine concentration...
Santos AS, Rodrigues MA, Bessa RJ, Ferreira LM, Martin-Rosset W.Having evolved as a grazing animal, a horse's digestive physiology is characterized by rapid gastric transit, a rapid but intense enzymatic digestion along the small intestine, and a long and intense microbial fermentation in the large intestine. The process of understanding and describing feed degradation mechanisms in the equine digestive system in general, and in the hindgut ecosystem in particular, is essential. Regardless of its importance for the nutritional status of the host, the significance of the cecum-colon ecosystem has not yet been fully understood, and few reports have focused d...
Borgia L, Valberg S, McCue M, Watts K, Pagan J.The aim of this study was to determine whether the glycaemic/insulinaemic responses to hay with non-structural carbohydrate (NSC, soluble carbohydrate) of 17% (HC), 10% (MC) or 4% (LC) differs in control horses and whether these responses differ between control and horses with polysaccharide storage myopathy (PSSM). Five clinically normal control horses and seven PSSM horses, all unfit and of Quarter Horse breeding (age 9.4 ± 3.4 years, body condition score range: 4.5-6). A crossover design compared the HC and LC hay, with horses randomly assigned to hay type for 5 days, and all horses fed th...
Suagee JK, Corl BA, Hulver MW, McCutcheon LJ, Geor RJ.Plasma insulin concentrations are elevated (hyperinsulinemia) in horses with obesity-associated insulin resistance. In other species, insulin resistance is partly due to reduced levels of insulin receptor and the insulin-sensitive glucose transporter, and, in vitro, chronic hyperinsulinemic conditions reduce the expression of these proteins. Consumption of grain-based concentrate feeds results in postprandial hyperinsulinemia in horses, and adaptation to these diets is associated with insulin resistance. As such, it is possible that the repeated, chronic postprandial hyperinsulinemia associate...
Terachi T, Inoue Y, Ashihara N, Kobayashi M, Ando K, Matsui T.The effect of several vitamin K homologs on plasma vitamin K concentration was determined to assess their potential as a vitamin K supplement for adult horses. Sixteen Thoroughbred horses consisting of 8 mares and 8 geldings, aged 8.4 ± 3.6 yr and weighing 520.8 ± 36.1 kg, were allocated to 4 groups (n = 4). Each group was given phylloquinone, menaquinone-4, or menadione at 58 µmol/d, or no vitamin K supplement for 7 d. Plasma samples were collected before feeding, and 2, 4, and 8 h after feeding on d 7, and plasma concentrations of phylloquinone and menaquinone-4 were determined. Plasma ph...
Norman T, Chaffin K, Schmitz D.The equine small intestine is challenging to evaluate ultrasonographically. In humans, hydrosonography has been used to improve ultrasonographic images of the small intestine. We hypothesized that fasting horses for 24 h would enhance the ability to image the small intestine transabdominally by separating intestinal loops and reducing intraluminal gas, and that the administration of intragastric contrast agent would further improve that ability. Ten healthy horses were examined ultrasonographically under three treatment conditions: (a) regular diet, (b) after a 24-h fast, and (c) fasted plus i...
Dugdale AH, Curtis GC, Cripps PJ, Harris PA, Argo CM.Changes in appetite, body mass (BM), body condition score (BCS), direct (ultrasonographic) and indirect (deuterium oxide dilution technique) measures of body fat were monitored in Welsh Mountain pony mares (n=11, 5-19 years of age) offered ad libitum access to a complete diet (gross energy 16.9±0.07 MJ/kg dry matter) for 12 weeks during summer (n=6; 246±20 kg) and winter (n=5; 219±21 kg). At the outset, each group comprised two thin (BCS 1-3/9), moderate (BCS 4-6/9) and obese (BCS 7-9/9) animals. For ponies that were non-obese at the outset, BM was gained more rapidly (P=0.001) in summer (0...
Muirhead TL, Wichtel JJ, Stryhn H, McClure JT.Serum selenium (Se), vitamin E, and resting thyroid hormone concentrations were measured in 201 horses in Prince Edward Island (PEI). Selenium concentrations were either marginal (0.0053 to 0.1200 ppm) or deficient (< 0.0053 ppm) in 79% of horses based on current reference ranges for Se in serum. Aged and young adult pleasure horses had a higher prevalence of inadequate Se concentrations compared to racehorses and broodmares (82% and 97% versus 45% and 72%, respectively). Overall, 13% of horses had inadequate (< 200 μg/dL) serum vitamin E concentrations; most of these were young pleasure hors...
van den Hoven R, Bauer A, Hackl S, Zickl M, Spona J, Zentek J.In this preliminary study, time-dependent changes in plasma CK and AST activity, tyrosine (Tyr), 3-methyl-histidine (3mHis), glucose and lactate concentrations were analysed in nine horses under two different conditions. Furthermore, intramuscular concentrations of Tyr, 3mHis and activities of cathepsin B, acid phosphatase (ACP), glucose-6-phosphate dehydrogenase (G6PDH) and mRNA expression of ubiquitin were determined at the same time. After studying the effects of exercise alone, the effects of exercise and feeding of an experimental protein/amino acid (AA) supplement were analysed. Horses w...
Jensen RB, Brokner C, Knudsen KE, Tauson AH.Four Icelandic (ICE) and four Danish Warmblood (DW) horses were used in a crossover study with two treatments to investigate the effect of breed and the effect of stage of maturity of haylage on the apparent total tract digestibility (ATTD) of a diet consisting of sugar beet pulp, black oats and haylage early or late cut. Fibre was analysed as crude fibre (CF), acid detergent fibre (ADF), neutral detergent fibre (NDF) and dietary fibre (DF = non-starch polysaccharides (NSP) plus lignin). In haylage all analysed fibre fractions increased with advancing stage of maturity, with the cell wall comp...
Sankey C, Henry S, Górecka-Bruzda A, Richard-Yris MA, Hausberger M.How do we bond to one another? While in some species, like humans, physical contact plays a role in the process of attachment, it has been suggested that tactile contact's value may greatly differ according to the species considered. Nevertheless, grooming is often considered as a pleasurable experience for domestic animals, even though scientific data is lacking. On another hand, food seems to be involved in the creation of most relationships in a variety of species. Results: In this study, we used the horse training context to test the effects of food versus grooming during repeated human-ho...
Graham-Thiers PM, Bowen LK.Plasma AA in horses fed either an all-hay or a hay and grain diet in a traditional format have not been investigated. Eight horses were divided into 2 groups: a hay group fed only grass hay or a hay and a grain group (HG) fed in a crossover design for two 5-wk periods. After the first period, horses were fasted overnight, followed by feeding with blood sampling every hour for 6 h. A 4-d total fecal and urine collection to evaluate N balance followed. A 10-d washout period separated the 5-wk feeding periods, during which horses switched diets. The second period was also followed by fasting, fee...
Wagner EL, Potter GD, Gibbs PG, Eller EM, Scott BD, Vogelsang MM, Walzem RL.Studies comparing the absorption and retention of various forms of trace minerals in horses have yielded mixed results. The objective of this study was to compare Cu and Zn absorption and retention in exercising horses where the mineral was supplemented in the sulfate or organic chelate form. Nine mature horses were used in a modified switchback design experiment consisting of seven 28-d periods. Horses were fed a diet consisting of 50% concentrate and 50% hay that was balanced to meet the energy, protein, Ca, and P requirements for horses performing moderate-intensity exercise. Horses were su...
Franz R, Soliva CR, Kreuzer M, Hummel J, Clauss M.It is assumed that small herbivores produce negligible amounts of methane, but it is unclear whether this is a physiological peculiarity or simply a scaling effect. A respiratory chamber experiment was conducted with six rabbits (Oryctolagus cuniculus, 1.57±0.31 kg body mass) and six guinea pigs (Cavia porcellus, 0.79±0.07 kg) offered grass hay ad libitum. Daily dry matter (DM) intake and DM digestibility were 50±6 g kg⁻⁰·⁷⁵ d⁻¹ and 55±6% in rabbits and 59±11 g kg⁻⁰·⁷⁵ d⁻¹ and 61±3% in guinea pigs, respectively. Methane production was similar for both species (0.2...
Masey O'Neill HV, Keen J, Dumbell L.The purpose of this study was to gain evidence on the prevalence of dental abnormalities in stable-kept horses in comparison with free-living horses. It is expected that free-living horses that graze for as much as 16 h/day will have fewer dental abnormalities than stable-kept horses. In this study, the latter group was fed a diet that was based on a relatively high-energy, cereal-based feed. This was thought to be a representative of common practice in domesticated, stable-kept horses. Compound diets such as this have previously been shown to increase the frequency of chewing cycles and decre...
Chameroy KA, Frank N, Elliott SB, Boston RC.Obesity and insulin resistance are risk factors for laminitis in equids and supplements containing chromium and magnesium might improve insulin sensitivity. Objective: A supplement containing chromium, magnesium and other nutraceuticals would alter morphometric measurements, blood variables, and insulin sensitivity in laminitic obese horses. Methods: Twelve previously laminitic obese (body condition score ≥ 7/9) horses were randomly allocated to treatment (n = 6) and control (n = 6) groups and 2 obese horses with clinical laminitis were included in the treatment group. Treated animals receiv...
Elia JB, Erb HN, Houpt KA.The natural diet of free-ranging horses is grass, which is typically high in fiber and calorically dilute, however diets for high performance domestic horses are often low in fiber and calorically dense. The aim of the study was to determine the motivation of horses for hay when fed a low roughage diet. Their motivation could be used to determine if low roughage diets compromise the welfare of horses. Eight mares were fed two different diets in counterbalanced order: ad libitum orchard grass hay; a complete pelleted feed (pellets). Each trial lasted three weeks, with a one-week transition peri...
Respondek F, Myers K, Smith TL, Wagner A, Geor RJ.Obesity and insulin resistance are risk factors for laminitis in horses and ponies, and diet can play an important role in modulating these risk factors. Dietary supplementation with prebiotic fibers, such as short-chain fructo-oligosaccharides (scFOS), has resulted in improvement of insulin sensitivity in obese dogs and rodents. Thus, we hypothesized that scFOS may reduce insulin resistance in obese horses and designed a study to evaluate the effect of dietary supplementation with scFOS on insulin sensitivity. Eight mature Arabian geldings (BW = 523.0 ± 56.5 kg) with an average BCS of 8 were...
Cawdell-Smith AJ, Scrivener CJ, Bryden WL.Invasion of the flowering heads of grasses by Claviceps spp. can produce sclerotia (ergots) containing several toxins. Ingestion of these toxins, through the consumption of paspalum (Paspalum dilatatum), can induce a range of clinical symptoms, including staggers. Cattle are the most commonly affected species, but although sheep and horses have been reported affected there are no published descriptions of paspalum staggers in horses. We describe two occurrences of paspalum staggers, the first in three Australian Stockhorse foals and the second in mature Standardbred horses. All three foals pre...
Westermann CM, Dorland L, Wijnberg ID, de Sain-van der Velden MGM, van Breda E, Barneveld A, de Graaf-Roelfsema E, Keizer HA, van der Kolk JH.The objective of this study is to assess the influence of acute exercise, training and intensified training on the plasma amino acid profile. In a 32-week longitudinal study using 10 Standardbred horses, training was divided into four phases, including a phase of intensified training for five horses. At the end of each phase, a standardized exercise test, SET, was performed. Plasma amino acid concentrations before and after each SET were measured. Training significantly reduced mean plasma aspartic acid concentration, whereas exercise significantly increased the plasma concentrations of alanin...
Dugdale AH, Curtis GC, Cripps P, Harris PA, Argo CM.Increased prevalence of obesity among UK horses and ponies demands evidence-based advice to promote weight loss. Objective: Restriction of dry matter intake (DMI) to 1% of body mass (BM, 67% [corrected] of predicted maintenance digestible energy [DE] requirements) would promote weight loss without compromise to health. Methods: Five mature (mean ± s.e. 10 ± 2 years), overweight/obese pony mares (BM, 257 ± 20 kg: body condition score [BCS] 6.8/9 ± 0.5) were studied over 12 weeks. Animals were individually housed. Daily provision of a chaff-based, complete diet (measured DE, 8.5 MJ/kg DM) wa...
Cotugna N, Snider OS, Windish J.Athletes involved in horse racing face weight restrictions like wrestlers and dancers; however, the literature is sparse pertaining to nutritional habits of jockeys. The practice of "making weight" causes these athletes to engage in potentially unhealthy practices. A gap in nutritionally sound practices and methods used by jockeys was identified and a desire for nutrition education was expressed to Cooperative Extension of Delaware by representatives of the riders at Delaware Park Race Track. Nutrition assessment was done using the Nutrition Care Process. Twenty jockeys were interviewed using ...
Bondo T, Jensen SK.This study assessed the effect of a vitamin E supplement given to pregnant mares on immunoglobulins (Ig) levels in foals. In addition, the fatty acid (FA) content and composition of the mares' milk was assessed. Milk α-tocopherol concentrations were compared between pregnant Danish Warmblood mares (n = 17) given a daily oral supplement of 2500 international units (IU) RRR-α-tocopherol in the last 4 weeks of pregnancy and a group of unsupplemented mares (n = 17) receiving 170-320 IU vitamin E daily originating from the feed. Milk α-tocopherol was higher in supplemented mares (36.7, 12.4 and ...
Murray MJ, Schaudies RP, Cavey DM.Epidermal growth factor (EGF)-like activity was measured in mares' colostrum and milk by radioreceptor assay. Milk samples were collected from 22 mares 1 or more times during early lactation. Samples of colostrum were taken after parturition and before the foal first suckled (presuckle), within 6 hours after the foal first suckled (postsuckle), and on days 1, 2, 4, and 8 of lactation. In the 5 mares from which milk samples were obtained at each sampling time, presuckle colostral mean EGF-like activity (17.8 ng/ml) was greatest (P less than 0.05). The mean values for EGF-like activity at all ot...
Bridges CH, Womack JE, Harris ED, Scrutchfield WL.Of 8 Thoroughbred foals in which osteochondrosis developed before weaning, 7 had serum copper and ceruloplasmin concentrations below normal. Three foals on one farm had serum zinc content high enough to suggest zinc toxicosis, and the liver of each foal contained abnormally high content of zinc. Four foals from the second farm had extremely low serum copper content, but normal serum zinc content. Evidence of environmental exposure to excess zinc was not found on either farm. The lesions in the zones of endochondral ossification of the afflicted foals were similar in many respects to those foun...
Ronen N, van Heerden J, van Amstel SR.Three cases of horses with nutritional secondary hyperparathyroidism (NSH) are described. The horses showed typical thickening of the maxillae and mandibular bones with or without lameness. Laboratory findings included elevated concentrations of parathyroid hormone (carboxy-terminal and mid-molecule fractions), alkaline phosphatase and an increase in the fractional excretion rate of serum inorganic phosphorus.
Kronfeld DS, Meacham TN, Donoghue S.The clinician may choose between two approaches to nutritional intervention. One is to evaluate the ration and make a painstaking effort to identify those specific factors operating in a particular case, then correct them. The second is to evaluate the ration, inspect for obvious aberrations, and, if finding none, proceed with no further delay to formulate an optimal diet, or a series, for the animals, and design a feeding program to suit farm management. Veterinarians should counsel clients on the possible or probable consequences of level of feeding on growth rate and clinical expression of ...
The Journal of nutritionDecember 30, 1998
Volume 128, Issue 12 Suppl 2698S-2703S doi: 10.1093/jn/128.12.2698S
Harris PA.In the first part of this century, there was little advancement in horse nutrition and little research was undertaken. However, in the last few years, there has been a great increase in interest in this whole area. This review surveys some of the more recent developments and how they have influenced feeding practices and also compares these with those feeding practices found at the start of this century. The review concentrates on the nutrition of the adult horse in work, exploring in particular what they are fed and how the nutrient value of these feeds is evaluated.
Mäenpää PH, Pirhonen A, Koskinen E.The effects of feeding two different vitamin-mineral concentrates on serum levels of vitamins A, E and D and some growth indicators were examined in 30 pregnant mares and 30 foals. One concentrate contained vitamins A and E and the other did not. Both contained vitamin D3. No differences (P greater than .05) in serum levels of retinol and alpha-tocopherol were observed between the feeding groups in the mares, whereas in the weanlings serum levels of dietary vitamins A and E increased (P less than .01) during late winter and early spring. However, the values did not increase to levels found in ...
Schiefer HB.Colitis "X" is a sporadic diarrheal disease of horses with clinical signs of dehydration, electrolyte imbalances and "shock"-like features. Macroscopic and microscopic findings include signs of disseminated intravascular coagulation, necrosis of colonic mucosa and presence of large numbers of bacteria in the devitalized parts of the intestine. Recently published work suggests that the causative agent may be Clostridium perfringens, Type A, but the bacteria are recoverable only in the preliminary stages of the disease. Excess protein and lack of cellulose content in the diet is thought to be th...
Pfister JA, Stegelmeier BL, Cheney CD, Gardner DR.Locoweed species (Astragalus and Oxytropis spp.) are a serious toxic plant problem for grazing livestock. Horses and sheep have been conditioned to avoid eating locoweed using the aversive agent LiCl. The objective of this study was to determine if previous locoweed intoxication affects food aversion learning in horses and sheep. Horses and sheep were divided into 3 treatment groups: control (not fed locoweed and not averted to a novel feed); locoweed-novel feed averted (fed locoweed and averted to a novel feed); and averted (not fed locoweed and averted to a novel feed). Animals in the locowe...
Williams ZJ, Bertels M, Valberg SJ.Type 1 polysaccharide storage myopathy (PSSM1) is a glycogen storage disorder of known cause whereas the basis for type 2 PSSM (PSSM2) is unknown. The same diet and exercise regime prescribed for PSSM1 is recommended for PSSM2; however, the benefit of these recommendations for PSSM2 is undocumented. The objectives of this study were to determine traits of PSSM2 Warmblood horses (WB), determine the changes in exercise responses that occur with a recommended low-starch/fat-supplemented diet and exercise regime, and determine if glycogen concentrations correspond to the severity of signs. Owners ...
Golding E, Al Ansari ASA, Sutton GA, Walshe N, Duggan V.Equine obesity is a significant health and welfare concern. The proportion of domestic horse populations that are overweight are as high as 45%. As the primary decision-makers for their horses' care, owners are theoretically ideally placed to identify whether their horses are appropriately conditioned, however, research in other countries has shown that many owners are unable to accurately judge their horse's body condition. In this study, through the comparison of body condition scoring (BCS) performed by an expert and the horse owners and interviews with owners, we aimed to identify the prop...
Gajardo G, López-Muñoz R, Plaza A, Uberti B, Sarmiento J, Morán G, Henríquez C.Tamoxifen (TAM), a selective modulator of estrogen receptors (SERMs) has been recently explored as a therapeutic option for the oral treatment of airway inflammation in the horse. The objective of this work was to establish pharmacokinetic parameters of TAM and its main metabolites in equines, as well as to determine its clinical safety in short-term treatments. Results: We determined TAM and its three main metabolites (4-OH tamoxifen, endoxifen, and N-desmethyl tamoxifen) in plasma after single administration of 0.25 mg/kg in healthy adult horses ( = 12). A maximum concentration of TAM w...
Mäenpää PH, Lappeteläinen R, Virkkunen J.Serum levels of retinol, 25-hydroxyvitamin D2, 25-hydroxyvitamin D3 and alpha-tocopherol were determined by high performance liquid chromatography from 142 Standardbred and Finnish Coldblooded Trotters aged three to 15 years. Blood samples were collected during January and July. Serum levels of retinol and alpha-tocopherol were about a third of those in man, with summer values indicating an increase in most horses. The relatively low serum concentrations of 25-hydroxyvitamin D and alpha-tocopherol suggest that during the winter season a deficiency of these vitamins may occur in horses in north...