Feeding practices in horses encompass the methods and strategies involved in providing nutrition to equine animals. These practices are designed to meet the dietary requirements necessary for maintaining health, supporting growth, and optimizing performance. Key components of equine feeding practices include the selection of forage and concentrates, balancing nutrients such as carbohydrates, proteins, fats, vitamins, and minerals, and considering factors such as age, workload, and health status. Feeding practices also address the timing and frequency of meals to align with the horse's digestive physiology. This page compiles peer-reviewed research studies and scholarly articles that explore various aspects of feeding practices, including nutritional requirements, feeding behavior, and the impact of diet on equine health and performance.
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 ...
Clarke LL, Ganjam VK, Fichtenbaum B, Hatfield D, Garner HE.The effect of feeding frequency and associated meal size on the renin-angiotensin-aldosterone system (RAAS) in seven horses was examined. A daily maintenance ration of hay-grain pellets was provided either as a multiple feeding regimen (MF), in which the ration was divided into six equal portions fed at 4-h intervals, or as a single large feeding (SF) given from 9 A.M. until 11 A.M. Plasma renin activity (PRA), aldosterone (PAC), cortisol (PCC), protein concentration (TP), packed cell volume (PCV), and serum sodium and potassium were measured serially. To prevent significant RAAS stimulation d...
Gibbs PG, Potter GD, Schelling GT, Kreider JL, Boyd CL.Mature ponies fitted with permanent ileal cannulas were used in a 3 X 3 Latin square experiment to quantify prececal, postileal and total tract digestion of hay protein. Coastal Bermuda grass (CB), containing 11.7% crude protein, and two qualities of alfalfa, containing 15.0% (low-protein alfalfa; LA) and 18.1% (high-protein alfalfa; HA) crude protein, were fed in coarsely chopped form at 2% of body weight daily. Total tract apparent digestibility of the N in HA (73.8%) was higher than that in CB (57.0%; P less than .05) and was slightly higher than that in LA (66.1%; P less than .10). Nitroge...
Stull CL, Rodiek AV.Two experiments were conducted to determine the response of blood glucose, insulin and cortisol levels to four common equine diets. Experiment 1 was designed to determine the diurnal variation of glucose and two glucoregulatory hormones, insulin and cortisol, in four fasting geldings. No diurnal variation was observed in either glucose or insulin levels during the 24-h sampling period. However, cortisol levels did exhibit a circadian rhythm, with elevated values observed in the morning and low values in the evening. Experiment 2 investigated the response of glucose, insulin, cortisol and selec...
Houpt KA, Perry PJ, Hintz HF, Houpt TR.Twelve ponies were fed their total daily ration either as one large meal or divided into six small meals. Pre- and post-feeding behavior was recorded six times a day. Blood samples were taken for 30 min before and two hr after the meal. Plasma protein increased from 7.0 to a peak of 7.3 g/dl with small meals and from 7.3 to 8.1 g/dl with large meals, and returned to pre-feeding levels by 90 min post-feeding. Hematocrit rose from 33.3 to 34.1% with small meals and from 33.0 to 36.0% with large meals. These rapid and short-lived increases indicate a decrease in plasma volume. Plasma osmolality r...
Roger T, Ruckebusch Y.The contractile activity of the equine large intestine exhibited a biphasic response to feeding: enhancement of migrating complexes passing along the colon and an increase of 50% in cyclic variations in smooth muscle at intervals of 20 min on the left ventral colon for a period of 5 to 7 h postfeeding. The cholinergic agonist, bethanechol (50 micrograms/kg subcutaneously), induced both the migrating complexes and the cyclic variations at intervals of 10-15 min. In contrast, the intra-arterial infusion of PGF2 alpha (3 micrograms/kg/min) increased the contractile activity during infusion, but w...
Denny JE.Horses receiving a pelleted or cubed dietary supplementation with roughage, have serum inorganic phosphate (SIP) concentrations consistently below an accepted mean of 1,032 mmol l-1 or 3, 1 mg dl-1. Further, it has been reported that the best eight, two-year-old Irish Thoroughbred track performers of 51 horses tested over a 10 month period, had significantly lower SIP concentrations than the worst eight track performers. In an endeavour to assess any nutritive effect on SIP concentrations and also to assess any effect of SIP concentrations on track performance, metabolic blood profiles from 30...
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...
Beaumier PM, Fenwick JD, Stevenson AJ, Weber MP, Young LM.Plasma and urinary levels of salicylic acid were examined in Standardbred mares after administration of various feeds, containing different compositions of hay. In addition, horses were administered acetylsalicylic acid orally and methyl salicylate topically. Elevated salicylic acid levels were observed in horse urine and plasma in animals fed lucerne hay. The plasma and urinary elimination of salicylic acid exhibited a diurnal pattern which was related to the type of feed and the feeding schedule. Within 24 h after oral administration of acetylsalicylic acid, plasma and urine salicylic acid l...
Schryver HF, Parker MT, Daniluk PD, Pagan KI, Williams J, Soderholm LV, Hintz HF.The voluntary salt consumption of mature unexercised horses was measured weekly for up to 45 weeks. Voluntary intake among horses was quite variable ranging from 19 to 143 g of salt per day and was inversely related to total salt intake (salt in feeds plus voluntary intake). Mean daily voluntary salt consumption was 53 g. Season of the year did not influence voluntary intake. In preference tests which evaluated every two choice combination of 0.2% and 4% NaCl in test diets fed daily for four days, ponies generally preferred diets containing the lower amount of salt. In similar preference studi...
Brown CM, Sonea I, Nachreiner RF, Obradovich JE.Using commercially available diagnostic reagents, serum immunoreactive gastrin activity was measured in five normal horses that were starved of food and water for 24 hours. Blood samples were taken every 15 minutes for two hours. The horses were then fed a pelleted diet for 15 minutes and samples were taken every 15 minutes for a further two hours. Three further samples were taken at hourly intervals. The total sampling period was seven hours. Basal immunoreactive gastrin activity was lower than that reported in other mammals, ranging from a mean of 7.0 pg/ml to 13.8 pg/ml. At 30, 60 and 75 mi...
Ralston SL.Problems related to feeding behavior in horses fall into three main categories: underconsumption, overconsumption, and abnormal consumption. Anorexia may be caused by a variety of diseases and overcome by removing the underlying causes (pain, fever), and physical or chemical stimulation of appetite. "Hypophagia" may be caused by poor dentition, disease, or stress. Again, removal of the cause or stimulation by physical or chemical means may improve intakes. Acute and chronic overconsumption of feeds are reflections of the normal controls (or lack thereof) of feeding in the horse. The only relia...
Russell MA, Rodiek AV, Lawrence LM.The effects of meal frequency and fasting on selected plasma free amino acids (PFAA) was studied in horses. Six 22-mo-old Quarter Horses were used in a replicated 3 X 3 Latin-square design in which each horse received one meal per day (1M), two meals per day (2M) or six meals per day (6M) for 2 wk. A complete pelleted ration was fed at a rate of 1.75% of body weight daily. The consumption of a meal by the horses fed 1M and 2M daily was followed by an increase (P less than .05) in plasma methionine. The highest levels were observed at 5 h and 3 h in the 1M and 2M treatments, respectively. The h...
Schryver HF, Millis DL, Soderholm LV, Williams J, Hintz HF.The effect of dietary aluminum on the absorption, retention and pathways of excretion of calcium, phosphorus, magnesium, zinc, iron and copper was studied in balance trials in mature ponies in a three by three latin square experiment. A basal diet consisting of one third each of oats, beet pulp and a commercial pelleted, complete horse ration and containing 336 ppm aluminum was supplemented with AlC1(3) . 6H2O. The middle and high level aluminum diets contained 1370 and 4500 ppm aluminum respectively. There was little difference in effect between the middle level aluminum and basal diets. The ...
Pagan JD, Hintz HF.Energy balance studies using indirect calorimetry were conducted with four mature equids ranging in weight from 125 to 856 kg. Each animal was fed three different levels of intake of the same diet. The amounts of digestible and metabolizable energy required for zero energy balance were determined by calculating regression equations for energy balance against energy intake. It was concluded that the maintenance requirements of equids vary linearly with body weight. No advantage was found for the use of weight for the comparison of equids within the range studied. The digestible energy (DE) requ...
Pagan JD, Hintz HF.Twenty-two pony mares were fed one of three diets that provided 93.0, 74.8 or 57.2 kcal of digestible energy (DE) per kg body weight per day. Milk samples were taken at 14 day intervals. A total of five samples were taken from each mare. The samples were analyzed for total solids, crude protein, lactose, total lipids, ash, calcium and phosphorus. Gross energy was calculated from composition data. Increases in energy intake decreased the concentration of total solids, protein, fat and gross energy of mare's milk. Energy intake had a greater influence on the mare's body condition than on milk en...
Maitho TE, Lees P, Taylor JB.The disposition of phenylbutazone (4.4 mg/kg), administered intravenously to six Welsh Mountain ponies, was described by a two-compartment open model. Pharmacokinetic parameters were not significantly different after morning dosing in comparison with afternoon dosing. When phenylbutazone (4.4 mg/kg) was administered orally to the same ponies, marked variations in time to peak concentrations were produced with different feeding schedules. When access to hay was permitted before and after dosing, the mean time to peak concentration was 13.2 +/- 1.2 h and double peaks in the plasma concentration-...
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...
Doreau M, Boulot S, Martin-Rosset W, Robelin J.The milk and nutrient intakes of 21 nursing foals of heavy breeds (adult weight: 800 kg) were determined at 1, 4 and 8 weeks of age. Lactose intake increased (P is less than 0.01) from 1 300 g/day at 1 week of age to 1 800 g/d at 8 weeks; fat decreased (P is less than 0.01) from 400 g/d to 300 g/d and protein did not vary (600 g/d). Energy and nitrogen intakes did not depend on the source of energy in the mother's diet. Milk, energy and nitrogen intakes were well related (r = 0.74 to 0.81) with foal growth between 1 and 4 weeks, but not between 4 and 8 weeks. The composition of weight gain sho...
Todhunter RJ, Stick JA, Slocombe RF.The effects of 3 feeding techniques on healing of a cervical esophageal mucosal resection and anastomosis were investigated in 16 horses. Horses were fed a moistened pelleted diet 1 of 3 ways: 1) per os (n = 5), 2) by nasogastric (n = 5) or 3) by esophagostomy tube (n = 6) until the 14th postoperative day. The pelleted diet was then fed orally in all horses until euthanasia on the 60th postoperative day. Immediate postoperative feeding per os was unsatisfactory, as only 2 of 5 horses survived in this group. Endoscopic evaluation revealed that mucosal dehiscence of varying degrees occurred, wit...
Ronéus BO, Hakkarainen RV, Lindholm CA, Työppönen JT.Vitamin E requirements of adult Standardbred horses were evaluated by tissue depletion and repletion. All the horses used in the study were given the same basal feed low in vitamin E during the eight months of the experiment. After an initial depletion period of two-and-a-half months the horses were divided into groups according to the amounts of DL alpha-tocopheryl acetate given (0 mg, control; 200, 600, 1800 and 5400 mg, respectively) as a daily oral supplement. The supplement study was followed by a second depletion period. Total vitamin E content and individual natural tocopherol isomers a...
Youket RJ, Carnevale JM, Houpt KA, Houpt TR.The effect of meal frequency on body fluid, glucose, triiodothyronine (T3), heart rate and behavior was measured in 10 ponies. A simple reversal design was used in which each pony received one meal/day (1X) for 2 wk and six meals/day (6X) for 2 wk. The total intake/day was held constant. Feeding was followed by a rise in plasma levels of glucose, T3, protein and osmolality. One large meal was followed by significantly greater changes in all of the variables than was a meal one-sixth the size. Plasma T3 rose from 41 +/- 5 (SE) ng/liter before feeding to 43 +/- 5 ng/liter following a small meal,...
Laut JE, Houpt KA, Hintz HF, Houpt TR.In order to determine if horses will increase their intake in response to caloric dilution, four pony geldings were fed ad lib a mixed grain diet either undiluted (3.4 Mcal/kg of digestible energy) or diluted (wt/wt) with 25% sawdust (2.6 Mcal/kg) or with 50% sawdust (1.7 Mcal/kg). The mean daily caloric intake was 17,457 kcal (3.4 Mcal diet), 17,546 kcal (2.6 Mcal diet) and 12,844 kcal (1.7 Mcal). The mean time spent eating was 246 (3.4 Mcal), 351 (2.6 Mcal), and 408 (1.7 Mcal) minutes/day. Meal size increased and meal frequency decreased with increasing dilution. The median long survivorship...
Hallebeek JM, van 't Klooster AT, Beynen AC.In various situations it is desirable to evaluate the diet of horses. Such situations occur when nutrition is considered as the cause of disease or symptoms or and when a diet or diet change raises concern about whether the animal is receiving sufficient nutrients. Ration evaluation consists of translating feed ingredients into nutrients supplied and comparing this with nutrient requirements. The basics of ration evaluation are illustrated by means of four examples of horse diets.
Asai Y, Matsui A, Osawa T, Kawai M, Kondo S.Ten Thoroughbred yearlings (5 females and 5 males) were used to examine the effect of time of grazing on pasture forage and digestible energy (DE) intake, bodyweight gain and DE expenditure in grazing activity. Five females were grazed for 17 h/day (LTG), 5 males were grazed for 7 h/day (STG) and they were fed differently. As a result, DE intake from pasture forage of LTG horses and STG horses was 27.3 and 12.7-13.9 Mcal/day, respectively. The average daily gain (ADG) of LTG and STG horses was 0.37 and 0.39-0.61 kg/day, respectively. The regression lines between DE intake and ADG of both group...
Ralston SL, Baile CA.This series of experiments was designed to investigate gastrointestinal (GI) stimuli that contribute to the normal control of feed intake in ponies. Osmotic stimuli were tested using intragastric (IG) infusion of .83 osmolar solutions of xylose (250 g) and NaCl (48 g) vs 2-liter water controls. Treatments were given 15 min before ponies were allowed ad libitum access to pelleted feed after a 4-h fast. Both hyperosmotic solutions delayed onset of the first meal (xylose: 72 ± 32 min, P<.05; NaCl: 71 ± 40 min, P<.1), resulting in an immediate reduction (P<.01) in feed intake. No effects were ob...
Fowler AL, Pyles MB, Hayes SH, Crum AD, Lawrence LM.Total fecal collection studies to determine digestibility of nutrients are costly and laborious. The use of externally dosed indigestible markers, such as titanium dioxide (TiO2), to estimate digestibility using spot samples could be advantageous, but studies validating their use in horses are inadequate. Two experiments were conducted to determine if TiO2 in fecal spot samples effectively estimated fecal output in horses. In Exp. 1, four mature horses were fed a forage-based diet (85:15 forage: concentrate) split into two equal meals with 1.75 ± 0.03 g TiO2/kg DM (10 g TiO2) per day ...
Wichtel JJ, Whitlock RH.Botulism was believed to be the cause of progressive symmetric myasthenia in 8 horses on a farm in North Carolina. One horse was found dead, 6 were euthanatized after becoming recumbent, and 1 affected horse recovered. Cecal and colonic contents of 2 horses were determined to contain Clostridium botulinum spores. Alfalfa hay that was fed to the horses contained spores and toxin.
Lezica FP, Filip R, Gorzalczany S, Ferraro G, de Erausquin GA, Rivas C, Ladaga GJ.In the present study, we determined the incidence and effects of season and weather on clinical manifestations of endophyte-infected ryegrass toxicity, performed chemical detection and pharmacological bioassays on ryegrass extracts, and conducted trials on: (i) effects of domperidone or metochlopramide on ovarian inactivity induced by endophyte-infected ryegrass; (ii) efficacy of buspirone or dihydrochloro phenyl piperazine (m-CPP) for preventing suppressed milk production induced by endophyte-infected ryegrass; and (iii) efficacy of domperidone to induce ovulation during winter anestrus. Mare...
van Dyk E, Neser S.The possible spread by horse faeces of plants that may become weeds in sensitive areas was investigated. It was found that the period 24-48 hours after ingestion of seeds included in rations was the retention time for seeds passing through the digestive system of the horse. The ability of seeds to germinate was not influenced by exposure to digestive fluids or sea-water. A feeding regime of compound feeds is suggested.
Hintz HF.Consistency of exercise and diet are important in colic prevention. Water should be offered before and after feeding. Fast-growing foals suckling heavily lactating mares may overeat grain at weaning. Creep feeding to accustom the foal to eating grain and gradually increasing the grain intake after weaning are helpful in preventing colic in foals. Stallions may overeat grain when taken off pasture in hot weather. Feeding hay initially and grain later helps avoid colic in these stallions. Type-D Clostridium perfringens may cause enterotoxemia in foals. Corn should be fed in moderation. High-Mg d...
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 ...
Pagan JD, Valberg SJ.Many myopathies in horses can be managed by exercise regimes and dietary modifications. This includes modifying the amount of nonstructural carbohydrate, fat, amino acids, vitamin E, and selenium based on the horse's specific myopathy, metabolic status, exercise program, and optimal body weight. Because dietary recommendations differ substantially between myopathies, it is imperative to establish a specific diagnosis. A nutritionist will help practitioners select from the myriad of offered products to ensure a balanced diet. This article provides detailed recommendations for a variety of myopa...
Kerley BS, Harris P, Jacquay E, Askins M, McClendon M, Adams AA.Feeding small meals (∼1 g/kg BW DM basis) providing >10% nonstructural carbohydrates (NSC; starch + water soluble carbohydrate; WSC) has resulted in an augmented insulin response (AIR) in insulin dysregulated (ID) horses, but it's unclear if AIR reflects NSC content or the g NSC/kg BW/meal. Objective: The insulinemic responses of ID (n = 7) and non-insulin dysregulated (NID; n = 8) horses fed four feeds (A = 6.8% NSC; B = 14.9% NSC; C = 35.5% NSC; D = 44.6% NSC) at three levels of NSC intake (0.06, 0.11-0.12 and 0.17-0.18 g/kg BW) were evaluated in a randomized Latin square design across two...
Stowe HD.The effects of 0.2, 0.4, 0.6, 0.8, 1.0 and 1.2% potassium, as K2CO3, in a purified diet were studied in orphaned foals of mixed breeding ranging in age from 11 to 57 days. Observations regarding feed intake, rate of gain, packed cell volume (PCV), erythrocyte counts (RBC), hemoglobin (Hb), leukocyte counts (WBC), and serum Na, K and Fe were made. Consumption of the 0.2% K diet after 8 days was inadequate to support growth. The foals consumed the 1.0 and 1.2% K diet at significantly higher rates (28.8 and 27.5 g/kg foal per day, respectively) than the 0.4% K diet. Rates of gain of foals fed 0.4...
Sloet van Oldruitenborgh-Oosterbaan MM, Annee MP, Verdegaal EJ, Lemmens AG, Beynen AC.Feeding a high-fat diet increases fat utilisation and may decrease glycogen utilisation resulting in a lower lactate production during moderate exercise. The effects of fat feeding on exercise- and lipid metabolism-associated blood variables were evaluated in 6 Standardbred horses during submaximal exercise. The horses were fed a high- (11.8% fat in total dietary dry matter) or a low-fat diet (1.5% fat) in a cross-over experiment with feeding periods of 4 weeks. At the end of each feeding period, the horses were subjected to a submaximal standardised stepwise exercise test on a treadmill. Bloo...
Breuhaus BA.To determine whether ingestion of fescue seed infected with the endophyte Neotyphodium coenophialum would alter thyroid function in adult horses. Methods: Original study. Methods: 4 adult mares that were not pregnant and 6 adult geldings. Methods: Thyrotropin releasing hormone stimulation tests were performed while horses received a standard diet and after infected seed (2.3 kg/d [5 lb/d]) had been fed for 1 and 2 months. Serum prolactin concentrations were measured to verify endophyte absorption. Results: Serum prolactin concentrations indicated that at least 8 of 10 horses absorbed the endop...
Schryver HF, Hintz HF, Craig PH.Calcium metabolism was studied by combined metabolic balance and kinetic methods in four young Shetland ponies fed a diet containing 0.4% calcium and either 0.2% or 1.2% phosphorus in a replicated 2 × 2 Latin square experimental design. Phosphorus retention and plasma phosphorus concentration were greater when the ponies were fed the high phosphate diet. The high phosphate intake decreased calcium absorption, urinary excretion and retention but increased total and endogenous fecal calcium excretion. However, the ponies were in positive calcium balance when fed either the basal or high phospha...
Lawrence LM, Williams J, Soderholm LV, Roberts AM, Hintz HF.Four mature Standardbred horses were used in a 2-period cross-over design experiment to evaluate the effect of feeding state (fed or fasted) on metabolic response to 2 repeated bouts of exercise. Horses were either fasted 15 to 16 h before exercise or fasted for 12 h and then fed 2 kg of whole corn 2.5 to 3 h before exercise. In the first period, 2 horses in each feeding state were exercised. In the second period, the treatments were switched. The exercise test consisted of 2 exercise bouts separated by a 90 min recovery period. Each exercise bout included a warm-up phase and a high intensity ...
Suagee-Bedore J, Shost N, Miller C, Grado L, Bechelli J.Older horses and those prone to obesity may be at a higher risk for inflammation than younger and leaner counterparts. Previous research indicated a postprandial elevation in plasma concentrations of interleukin-1β (IL-1β), a pro-inflammatory cytokine, after consuming 1.2 g of non-structural carbohydrates/kilogram of body weight. However, these studies utilized horses of mixed age and body condition. The current study evaluated post-prandial IL-1β concentrations in horses specifically comparing lean to over-conditioned and middle aged to older. Our results suggest that at least two weeks of...