Feed intake in horses refers to the amount and type of feed consumed by horses, which can vary based on factors such as age, activity level, health status, and environmental conditions. It is a critical aspect of equine management, influencing growth, performance, reproduction, and overall health. Feed intake can be affected by the nutritional content of the diet, palatability, feeding practices, and physiological needs of the horse. Understanding feed intake patterns and requirements is essential for formulating appropriate feeding strategies. This page compiles peer-reviewed research studies and scholarly articles that explore the determinants of feed intake, its impact on equine physiology, and strategies for optimizing feeding practices in horses.
Caple IW, Bourke JM, Ellis PG.The calcium and phosphorus nutrition of thoroughbred racehorses was assessed by analysis of serum and urine samples collected from 90 horses in 1975 and 139 horses in 1980-81 at racetracks in Melbourne. Horses that were excreting greater than 15 mumole Ca/mosmole and which had a calcium to creatinine clearance ratio greater tha 2.5% were considered to have adequate Ca intake. Horses that were excreting greater than 15 mumole P/mosmole and which had a phosphorus to creatinine clearance ratio greater than 4% were considered to have excessive phosphorus intake. Sixty-percent of the horses sampled...
Frape DL, Tuck MG, Sutcliffe NH, Jones DB.1. The rate of passage of chromic oxide (Cr) was similar in the pony and rhinoceros. 2. Higher apparent amounts digested were found using 4N-HCl-insoluble ash (AIA) than those determined by Cr, but overall digestibilities were similar for the two species. 3. An abrupt increase in the starch content of the horse diets increased the number of faecal ciliate protozoa. Only when the overall feed intake was increased in horses receiving a high dietary proportion of starch were the numbers depressed. 4. When the rhinoceros received 109 kJ apparent DE per kg bodyweight daily (716 kJ/W0.75 daily) it m...
Ralston SL, Van den Broek G, Baile CA.The feeding patterns of five pony geldings fed pelleted diets ad libitum were quantified for five 24-hr periods. Eighty percent of a given pony's total daily intake (6.3 ± .81 kg or 2.9 ± .41% BW) was eaten in 10 ± .9 separate meals. Each meal averaged .49 ±.13 kg of pellets and lasted 44 ± 10 minutes. The mean intermeal interval was 84 ± 10 min, with a maximum of 3 hour. The animals spent 38 ± 7.2% of a 24-hr period engaged in eating activities, 84 ± 3.7% of which was devoted to meals, the other 16% spent in nibbling activities. Forty-nine percent of the total daily intake was consume...
Ellis RN, Lawrence TL.In two separate experiments food intakes and heart rates were monitored in New Forest and Welsh filly foals maintained at constant weight (by energy restriction) or allowed to grow normally for 180 (New Forest) or 147 (Welsh) days. Subsequent to these periods voluntary food intakes from feeding the same diet for 107 days (New Forest ponies) and herbage dry matter intakes from allowing free access to pasture for 42 days (Welsh ponies) were recorded. In the ponies maintained at constant live-weight food intakes and heart rates declined to reach and remain at new low levels. Herbage dry matter co...
Butler KD, Hintz HF.A pelleted ration was fed limited or ad libitum to two groups of seven Shetland 8-month-old ponies for 117 days. During the last 56 days, gelatin was added to the diets of four animals in each of the two intake groups. Gelatin was added at levels of 30 and 90 g per 100 kg body weight for the first and second 28-day periods, respectively.
Ponies fed the diet ad libitum consumed 180% more feed, had 50% greater rate of hoof growth (.384 ± .009 vs .254 ± .008 mm/d), 200% greater increase in height at the withers and 425% greater increase in body weight than ponies fed the limited level. The h...
Matsuoka T.Gelded horses of mixed breeding, ranging in weight between 360 and 455 kg, were fed pellets that contained monensin at concentrations of 279, 124, 31, and 0 ppm. Of 2 horses fed 279 ppm (253 g/T), both died. Of 3 horses fed 125 ppm (113 g/T), 1 died; feed intake was reduced in the 2 survivors. Of 3 horses fed 31 ppm (28 g/T), 1 had a transitory reduction in feed intake and the other 2 remained clinically normal. The 2 horses fed 0 ppm remained clinically normal. Monensin was also given to horses by gavage, at dosages of 1, 2, 3, 4, or 20 mg/kg of body weight. The LD50 was estimated to be betwe...
Brown RF, Houpt KA, Schryver HF.In two adult horses doses of 0.02-0.03 mg/kg diazepam, intravenously, increased 1 hr intake 54-75% above control levels. Intake was stimulated when the diet was a high grain, calorically dense one and also when the diet was a high fiber, calorically dilute one. Two young rapidly growing weanling horses showed an even more pronounced stimulation of intake. Following diazepam 1 hr intake was increased 105-240% above control lelvels. Promazine at a dose of 0.5 mg/kg also stimulated intake in adult horses, but not as markedly as did diazepam. A transquilizer and a neuroleptic appear to have a stim...
Hintz HF.Recent studies on the digestive physiology of the horse are reviewed. It was suggested that the small intestine is the primary site of digestion and absorption of protein, soluble carbohydrates, most minerals, fats, fat soluble and water soluble vitamins. The large intestine is the primary site of fibre digestion and net water absorption. Significant amounts of phosphorus are also absorbed from the large intestine. Many factors such as rate of passage, processing of feeds, level of intake, work and maturity of plant may influence digestive ability.
Equine coronavirus (ECoV) leads to outbreaks with variable morbidity and mortality. Few previous reports of risk factors for infection are available in the literature. Unassigned: To describe unique clinical findings and risk factors for infection and development of clinical disease. Unassigned: 135 horses on a farm affected by ECoV outbreak. Unassigned: Retrospective cohort study. Data obtained included age, breed, gender, activity level, housing, and feed at the onset of the outbreak. Factors were evaluated for assessment of risk of infection using simple logistic regression or Fisher's exac...
Wolford AN, Coverdale JA, Leatherwood JL, Pinchak WE, Anderson RC, Wickersham TA.Eight previously cecally cannulated Quarter Horse geldings were utilized in a crossover design with two 28-d periods with a 21-d washout period between to evaluate the influence of housing on the cecal environment and dry matter intake (DMI). Horses were adapted to diet and housing from day 1 to 19, DMI was determined from day 20 to 24, and cecal fluid was collected on day 28. Horses were paired by age and body weight (BW) and randomly assigned to treatment. Treatments consisted of housing horses individually in stalls or group housed in a pen. Regardless of treatment, all horses were individu...
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...
Mack JK, Remler HP, Senckenberg E, Kienzle E.The objective of this study was to investigate the effects of a different energy supply on the development of Warmblood foals with a focus on examining the recommended allowances of the German Society for Nutrition Physiology. Methods: Two groups of foals received different amounts of concentrates from the 1st until the 6th month of life. With regards to the total energy content, the rations were composed to either comply with the recommendations (6) (group "Norm", n=15) or to exceed those by approximately 20% (group "Zulage", n=16). The supply with concentrates of the group "Norm" aimed for a...
Bampidis V, Azimonti G, Bastos ML, Christensen H, Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of 4-methyl-5-vinylthiazole [15.018] belonging to chemical group 29 (thiazoles, thiophene and thiazoline), when used as sensory additive (flavourings) in feed for all animal species. The FEEDAP Panel concluded that 4-methyl-5-vinylthiazole [15.018] was safe at the maximum proposed use level of 0.5 mg/kg complete feed for veal calves (milk replacer), dogs, salmonids and ornamental fish. For the other species, the calculated safe concentrations in complete feed are: 0.4...
Viljanto M, Kaabia Z, Taylor P, Hincks P, Muir T, Habershon-Butcher J, Bailly-Chouriberry L, Scarth J.Boldenone is an anabolic-androgenic steroid (AAS) that is prohibited in equine sports. However, in certain situations, it is endogenous, potentially formed by the microbes in urine. An approach to the differentiation based on the detection of the biomarkers Δ1-progesterone, 20(S)-hydroxy-Δ1-progesterone and 20(S)-hydroxyprogesterone was assessed, and their concentrations were monitored in the urine of untreated female horses (n = 291) alongside boldenone, boldienone, testosterone and androstenedione. Using an ultra-sensitive analytical method, boldenone (256 ± 236 pg/mL, n = 2...
Inokuma H, Kanaya N, Fujii K, Anzai T, Maeda K, Okuda M, Onishi T.Twelve horses kept at a riding club suffered from pyoderma. All the horses displayed crusting, scaling and alopecia. The lesions were distributed in the chest, back, rump and limbs. Some of the horse patients also showed epilation with an attached crust similar to a 'paintbrush lesion' of dermatophilosis, but normal skin flora or opportunistic pathogenic bacteria were only isolated from the lesions. Some patients clearly showed weight loss, anemia and low levels of serum protein and cholesterol. General condition and skin lesions of the patients were improved gradually with improvement of feed...
Ragnarsson S, Víkingsdóttir SV, Stefánsdóttir GJ.The natural behaviour of horses is to spend the majority of their time on feed intake The feeding of stabled horses is, however, often far from that, as their feed intake is limited to their nutritional requirements. In order to approach their natural foraging time, it is important to extend the feed intake time of stabled horses. The aim of this study was to estimate if the feed intake time differs when feeding haylage in a haynet, hayball, metal corner manger, or from the box floor. The experimental design consisted of a Latin square, occurred across four days with four adult Icelandic horse...
Bampidis V, Azimonti G, Bastos ML, Christensen H, Durjava M, Dusemund B, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of sodium ferrocyanide and potassium ferrocyanide as technological feed additives for all animal species. In its previous opinion on the safety and efficacy of the additives, the FEEDAP Panel concluded that the use of sodium ferrocyanide and potassium ferrocyanide is safe, when added to sodium chloride at a maximum content of 80 mg ferrocyanide anions (anhydrous)/kg for turkeys for fattening and laying hens and other laying/breeding birds, all porcine species and categori...
Leishman EM, Sahar M, Cieslar S, Darani P, Ellis JL.To properly formulate diets, the ability to accurately estimate feed intake is critical as the amount of feed consumed will influence the amount of nutrients delivered to the animal. Inaccurate intake estimates may lead to under- or over-feeding of nutrients to the animal. Individual differences in equine forage intake are well-known, but predictive equations based on animal and nutritional factors are not comprehensive. The objective of the present study was to consolidate the current body of knowledge in the published literature on voluntary forage DM intake (VFDMI) in equines and conduct a ...
Springer RW, Cherry NM, Muir JP, Raub RH, Wellmann KB, Jones TN.Recent changes in legislation have put hempseed meal (Cannabis sativa L.; HSM) under consideration as a potential livestock feedstuff. Digestibility of HSM has been researched in other species, however, there are little data in horses. The study objective was to determine the in vitro true digestibility (IVTD) of HSM compared to common equine feedstuffs. An in vitro split-split plot design used four geldings (8.5 ± 3.9yr; 558.4 ± 31.0kg; 6.0 ± 0.4 BCS) to investigate the IVTD of HSM compared to alfalfa hay (ALF), Coastal Bermudagrass hay (CBH), soybean meal (SBM), rice bran pellets (RBP), a...
Villa RE, Azimonti G, Bonos E, Christensen H, Durjava M, Dusemund B, Gehring R, Glandorf B, Kouba M, López-Alonso M, Marcon F, Nebbia C, Pechová A....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of an essential oil from the fresh or dried flowering stems of L. (clary sage oil) when used as a sensory additive in feed and in water for drinking for all animal species. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive under assessment is considered safe up to the maximum use level in complete feed of 15 mg/kg for veal calves (milk replacers), cattle for fattening, sheep/goats, 10 mg/kg for horses, 20 mg/k...
Villa RE, Azimonti G, Bonos E, Christensen H, Durjava M, Dusemund B, Gehring R, Glandorf B, Kouba M, López-Alonso M, Marcon F, Nebbia C, Pechová A....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a preparation of CNCM I-1077 as a zootechnical feed additive for several animal species. The additive, existing in a not-coated and a coated form, is currently authorised for use in feed for calves, cattle for fattening, dairy cows, dairy goats and dairy sheep, lambs, all minor ruminant species for fattening and rearing, horses and camelids for fattening and rearing. This application regards the request for the extension of use in all ruminants and camelids reared for...
Webster AP, Price T, Ingersoll T, Suagee-Bedore JK, White RR.Our objectives were to use a quantitative literature review to explore dietary and feed factors influencing apparent total-tract digestibility of dry matter (DMD), crude protein (CPD), neutral detergent fiber (NDFD), ether extract (EED), non-structural carbohydrates (NSCD), non-fiber carbohydrates (NFCD), and residual organic matter (rOMD) in equine diets, and to assess their contributions to digestible energy (DE) supplies. Data from 54 studies were modeled using linear mixed-effect regressions, with publication as a random effect to account for study variability. For each nutrient, five mode...
Karačonji IB, Jelača T, Jurič A, Vrdoljak AL.Opiates such as morphine and codeine are substances often misused to improve the performance of racing horses during competitions and are therefore on the International Federation for Equestrian Sports' list of prohibited substances. However, a positive antidoping test may be due to the consumption of feed (mainly lucerne or oats) contaminated by opium poppy containing the alkaloids morphine and codeine. In order to determine whether a positive antidoping test is the result of an intentional abuse of opiates or consumption of feed contaminated by poppies, we optimised conditions for the extrac...
Kwaß LM, Khiaosa-Ard R, Zebeli Q, Sulyok M, Milojevic V, Metzler-Zebeli BU.The occurrence of biotoxins and chemical residues in marketed horse feeds has direct influences on horse health but has not been studied yet. Objective: The study investigated the exposure and health implications of contaminants in various horse feedstuffs available on the European market. Methods: A total of 108 feed samples representing diverse product categories such as hay, processed roughage products, grains, and various supplementary feeds were collected from different European countries and analyzed for contaminants, including mycotoxins, phytoestrogens, pesticides, and veterinary drug ...
Bachmann M, Bochnia M, Wensch-Dorendorf M, Glatter M, Schäfer S, Simroth K, Greef JM, Zeyner A.Feed intake and digestibility are important indicators for sufficient nutrient supply, but they can be assessed only to a limited extent in horses on pasture. In horses, feed intake is embedded in a complex behavioural pattern of searching, selecting, chewing and almost constant movement called foraging. The objectives of this study were to estimate organic matter intake (OMI) and organic matter digestibility (OMD) in six horses, 24 h/day on pasture, based on plant alkanes and synthetic n-hexatriacontane (C) excretion. A multi-compartmental model was fitted to the marker excretion and the C m...
O'Reilly K, Aldworth-Yang S, Catalano DN.There are many different concentrate feeders available to horse owners, but little data exists on feeder effect of equine intake rate. Rapid consumption ("bolting") is associated with issues such as esophageal obstruction. Objective: The objective of this study was to evaluate three common concentrate feeders on intake rate. We hypothesized horses would have the slowest intake rate when fed from the trough. Methods: Four geldings were fed 0.454 kg of concentrate from a pan on the ground (P), shallow trough (T), or hanging feeder (H). Horses were randomly assigned a first feeder and then rotate...
Li M, Xu Z, Sun L, Cheng Z, Yu Y, Chen Y, Li F, Zang C.This study aimed to investigate the effects of dietary NFC/NDF ratio on nutrient apparent digestibility, fecal fermentation parameters, microbial diversity, and plasma metabolomics in Yili horses. Twenty-four healthy Yili horses with similar body weights (406 ± 22.73 kg) were divided into four groups, each with six replicates: the Control Group (CG), Low-NFC Group (LG), Medium-NFC Group (MG), and High-NFC Group (HG). The experiment lasted 52 d, comprising a 7-day adaptation period and a 45-day experimental period. Total fecal collection was conducted from days 41 to 45 to calculate nutrient a...
Huisman I, Groenestein CM, Vellinga TV, Pishgar-Komleh SH.Sustainability is gaining growing attention within the equine sector. Sustainability consists of various subjects including feed and nutrition, resource efficiency, animal welfare, carbon footprint (CFP) and biodiversity, for example. Studies in horse research focus mainly on behaviour and welfare. Little information is available about the environmental impact of equids. The few studies that can be found are principally concerned with local impact, such as nitrogen leaching or ammonia concentrations in bedding. Little is known about greenhouse gas emissions (GHG) for horses, although GHG emiss...
Daniels S, Martin S, Harris P, Moore-Colyer M.The in vitro gas production system (GPS), developed to estimate degradation of ruminant feedstuffs, has been adapted for equine use. This study aimed to characterise the bacterial community profile and metabolome of donor faeces and faecal inoculum within the GPS when fermenting the same diet as faecal donors. Six Welsh ponies on identical diets were faecal donors with samples collected for microbiome profiling and system inoculation. Gas production (manual pressure transducer technique) was performed for 156 h with 2 replicate bottles from each donor harvested at 8,20,28 and 36 h. Faecal an...
Villa RE, Azimonti G, Bonos E, Christensen H, Durjava M, Dusemund B, Gehring R, Glandorf B, Kouba M, López-Alonso M, Marcon F, Nebbia C, Pechová A....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the efficacy of feed additives obtained from the leaves of L.: ginkgo tinctures as sensory additives for all animal species and ginkgo extract as a sensory additive for horses, dogs, cats, rabbits and guinea pigs. In previous assessments, a sensory analysis of ginkgo extract was performed, which showed that aqueous solutions of ginkgo extract have an intense aroma, significantly different from plain water. No evidence was provided to show that the additives would impart flavour to a food or fee...
Stegelmeier BL, Davis TZ.Many toxic plants are unpalatable to horses and are not eaten when alternative forage is available. However, when such plants contaminate prepared or baled feed and forage, herd competition and improved palatability can alter acceptance and thereby cause equine plant poisonings. Dehydropyrrolizidine alkaloid-containing plants; cocklebur; Salvia reflexa; kleingrass, switchgrass, and other saponin-containing grasses; jimson weed, black henbane, and other tropane alkaloid-containing plants; lantana; Cassia spp and other myotoxic plants; castor bean; cyanogenic glycoside-containing plants; thiamin...
Prasad S, Patel B, Kumar P, Lall R.Postbiotics, which are preparations of inanimate microorganisms and their components, have emerged as a promising functional ingredient in animal health and nutrition. Postbiotics are primarily composed of microbial cell fractions, metabolites, enzymes, vitamins, polysaccharides, and short-chain fatty acids. Unlike probiotics, postbiotics do not contain live microorganisms, which strengthens their greater stability and safety in feed/food formulations. Postbiotics offer several beneficial effects, including antioxidant, anti-inflammatory, immune-modulatory, and antimicrobial actions. They enha...
Hart KJ, Hegarty MJ, Hart EH.It is more evident that horse health is linked to the gastrointestinal tract and microbial community structure (MCS) as affected by diet. There are many marketed feeds available to enhance nutrition for horses, however the effects of these feeds on hindgut MCS are largely unknown. Objective: The aim was to test the effect of a complementary forage feed (FF) on the fermentation profile and MCS in contrasting basal diets. Methods: A 2×2 factorial design was used to assess the effect of basal diet, forage only (FOR) or forage/concentrate (MIX), and presence/absence of FF on fermentation paramete...
Aguirre Siliezar K, Datu C, Proia K, Rotstein D, Nemser SM, Tyson GH, Ragsdale JM, Wilkes RP, Baker RE, Carossino M, Del Piero F, Sasaki E, Yant P....A multi-state outbreak of equine botulism occurred between December 2022 and March 2023 in the United States. Follow-up and testing were performed on 42 horses, including 24 that died or were euthanized in the outbreak that affected ~98 horses. Affected horses had all been exposed to the same commercial feed. Clinical signs included progressive muscle weakness and tremors, recumbency, and colic. No significant gross or microscopic abnormalities were observed on autopsy. Feces and gastrointestinal content were tested for various infectious agents, including botulinum toxin; fecal samples from 2...
Wei J, Wei L, Ullah A, Geng M, Zhang X, Wang C, Khan MZ, Wang C, Zhang Z.Herbivorous animals rely on complex gastrointestinal systems and microbial communities to efficiently digest plant-based diets, extract nutrients, and maintain health. Recent advances in metagenomic technologies have enabled high-resolution, culture-independent analysis of gut microbiota composition, functional potential, and host-microbe interactions, providing insights into microbial diversity across the herbivore digestive tract. This review summarizes key findings on the gastrointestinal microbiota of herbivores, focusing on ruminant foregut and non-ruminant hindgut fermentation. Ruminants...
Bettio MK, Vidal T, Rose JJ, Jois M, Flavel M, Petrovski S.The gastrointestinal microbiota plays a critical role in horse health and performance. While sugarcane-derived polyphenols have shown microbiota-modulating properties in other species, their effects in horses remain unexplored. Objective: This study investigated whether supplementation with a sugarcane-derived polyphenol feed material modulates the hindgut microbiota of healthy adult horses. Methods: An observational longitudinal study was conducted on six horses over 12 weeks. Faecal samples were collected at three time points: baseline (P1), during supplementation (P2), and post-supplementat...
Park C, Jeong C, Son M, Yi J.This study evaluated a 181-day finishing system for horses entering the Korean meat chain by comparing retired thoroughbred geldings and Belgian-crossbred geldings under identical management and an ad libitum forage-based total mixed ration. Ten geldings ( = 5 per group) were individually housed, with body weight and feed intake recorded monthly. After slaughter, carcass traits and meat quality grade were assessed, and longissimus thoracis et lumborum samples were analyzed for proximate composition. Belgian-crossbreds consumed more dry matter (18.68 vs. 13.60 kg DM/day), corresponding to 2.3% ...
Villa RE, Azimonti G, Bonos E, Christensen H, Durjava M, Dusemund B, Gehring R, Glandorf B, Kouba M, López-Alonso M, Marcon F, Nebbia C, Pechová A....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of tea tree oil obtained from leaves and terminal branchlets of (Maiden & Betche) Cheel when used as a sensory additive for all animal species. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that tea tree oil was very unlikely to be of safety concern for long-living and reproductive animals and is of no concern for target species for fattening at the following concentrations in complete feed: 1.1 mg/kg for chickens for f...
Boshuizen B, Willems M, De Maré L, Hosotani G, De Oliveira JE, Horemans B, Vidal Moreno De Vega C, Verdegaal EJMM, Delesalle C.Aleurone, a bioactive wheat bran component, has been shown to modulate host metabolism and gut microbiota, but its effects across different compartments of the equine gastrointestinal (GI) tract remain unclear. In this study, we aimed to characterize aleurone-derived metabolite profiles using an fermentation model with digesta from three equine GI compartments (jejunum, cecum, and colon). Unassigned: Three substrates (control feed, aleurone-containing feed, and pure aleurone) were fermented over 72 h, and targeted metabolomics was performed on 38 metabolites. Unassigned: Significant substrate...
