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.
Stick JA, Derksen FJ, Scott EA.Cervical esophagostomy for tube feeding was evaluated in 11 ponies. Minor complications responded to supportive therapy in 8 ponies. Two died of complications, and 1 pony had a permanent fistula because of persistent infection. There was a positive correlation between the duration of tube feeding and the event of closure of the esophageal stoma after the tube was removed. There was no difference in the frequency of complications related to duration of tube feeding. When the distal end of the feeding tube was located in the thoracic portion of the esophagus, instead of in the stomach, tubes wer...
Orpin CG.Microscopic examination of horse caecum contents revealed vegetative growth of phycomycete fungi on particles of digesta, and uniflagellated cells similar to fungal zoospores in the liquid phase. Three morphologically distinct isolates of strictly anaerobic phycomycete fungi were obtained from the caecum contents and cultured in vitro. Two of the isolates were able to utilize a wide range of plant carbohydrates for growth, including alpha-cellulose, xylan and particulate starch, and extensively digested water-insoluble plant tissues.
Doige CE, McLaughlin BG.Hyperplastic goitre was observed in seven newborn foals. Several were weak at birth and died in the first 48 hours of life. Only one foal had myxedema and only three of the seven had obvious enlargement of the thyroid at necropsy. It is suggested that the goitre observed was caused by a dietary deficiency of iodine.
Donoghue S, Kronfeld DS, Berkowitz SJ, Copp RL.Four diets were fed to pony fillies for 40 weeks. One group received a basal diet low in carotene, designated mildly deficient. Other groups were fed basal diet plus vitamin A propionate equivalent to 12 (control), 1,200 (mildly intoxicated) or 12,000 (severely intoxicated) microgram retinol/kg body weight/day. The mildly deficient group exhibited impairment of growth and hematopoiesis with decreased serum concentrations of iron, albumin and cholesterol prior to depletion of liver vitamin A. Growth was depressed in mildly intoxicated and severely intoxicated fillies. The latter became debilita...
Doreau M, Martin-Rosset W, Barlet JP.Twenty-one circadian blood sample profiles were made in heavy brood mares during pregnancy, lactation or the dry, non-pregnant period. The mares were fed forage-rich diets containing different levels of energy and nitrogen (table 1). Each profile consisted of 7 samples taken at 8 a.m., 11 a.m., 3 p.m., 7 p.m., 11 p.m., 4 a.m. and 8 a.m. The animals were fed at 8:30 a.m. The eleven plasma components evaluated were glucose, non-esterified fatty acids, beta-hydroxybutyrate, acetate, alanine, insulin (energy metabolites), urea, total protein (nitrogen metabolites), calcium, inorganic phosphorus an...
Cymbaluk NF, Schryver HF, Hintz HF.The effects of copper intake on stable copper and 64Cu metabolism and on the excretory pathways of absorbed copper were examined in ponies. Bile and feces collected from two bile duct-cannulated ponies following an intravenous dose of 64Cu showed that bile was the main route of endogenous copper excretion. Stable copper and 64Cu metabolism were examined in three intact ponies fed dietary copper to provide 5.6, 16.6 and 25.7 mg Cu/100 kg body weight/day. The amount of copper excreted in urine was not influenced by dietary treatment. Stable copper absorption and 64Cu retention significantly incr...
Luther DG, Cox HU, Dimopoullos GT.Fatty acid composition of plasma lipids of normal horses was determined. Four fatty acids (C16:0, C18:0, C18:1, and C18:2) comprised 86.73% of the total, with C18:2 comprising 44.04% of the total. Eight other fatty acids were found in small amounts. Unsaturated fatty acids constituted 66% of the total. Marked variation was demonstrated in fatty acid occurrence and distribution in the sterol ester, triglyceride, phospholipid, and free fatty acid fractions.
Doreau M, Martin-Rosset W, Barlet JP.In an experiment comparing pregnant then lactating mares with dry non-pregnant mares, the changes in plasma components were studied as indicators of the metabolic utilization of energy (glucose, non-esterified fatty acids, beta-hydroxybutyrate), nitrogen (urea, proteins) or minerals (calcium, phosphorus, magnesium). The mares were fed daily 2 kg concentrate and hay ad libitum. Beta-hydroxybutyrate, magnesium and to a lesser extent glucose were the only constituents whose levels were affected within the period starting one month before and ending one month after foaling. The increase in food in...
Cymbaluk NF, Schryver HF, Hintz HF, Smith DF, Lowe JE.The effects of molybdenum ingestion on copper metabolism were investigated in bile duct-cannulated ponies fed diets containing 1.01, 27.4 and 107.3 ppm molybdenum. Copper metabolism was assessed by examination of 64Cu and stable copper excretion in feces, bile and urine. The addition of molybdenum to the diet decreased copper absorption and retention as a consequence of increased excretion of dietary copper in feces and increased excretion of absorbed copper in bile. Only 5% or less of the absorbed copper was excreted in urine regardless of dietary treatment. Biliary molybdenum excretion was o...
Rose RJ.In this article a physiological approach to fluid therapy is discussed, commencing with examination of fluid distribution in the normal horse. The functions of individual plasma electrolyte concentrations are considered and practical causes of acid-base disturbances discussed. When fluid administration is necessary, selection of the route for fluid administration as well as the type of fluid are important considerations and these must be adjusted to the needs of the individual case. Balanced polyionic solutions appear to be most suitable for general use because normal saline can produce hypoka...
Hambleton PL, Slade LM, Hamar DW, Kienholz EW, Lewis LD.Four isocaloric diets containing 4, 8, 12 and 16% dietary fat (as soybean oil) were fed to four horses at four intervals according to a Latin square design. After 3 weeks of conditioning at each interval, diet effects were evaluated by trotting all horses at 3.2 m/sec for 6 hours. Pre- and posttrotting responses were measured in muscle and liver glycogen, serum long-chain fatty acids, serum electrolytes, serum enzymes, serum cholesterol, plasma glucose, packed cell volume and hemoglobin. Dietary fat was highly correlated with exercise-induced plasma glucose changes and with cholesterol concent...
Bryans JT.The immunogenic potency and safety of a chemically inactivated equine herpesvirus 1 vaccine with added adjuvant was evaluated by testing serum-neutralizing and complement-fixation antibody responses of pregnant Thoroughbred mares. The vaccinated population comprised 321 pregnant mares on 7 farms; 3 in Normandy, France; 1 in Kildare, Ireland; and 3 in central Kentucky. The pattern of antibody response to vaccination was found qualitatively and quantitatively similar to that of pregnant mares previously vaccinated and determined by challenge exposure to be immune to abortigenic infection under e...
Gulick BA, Liu IK, Qualls CW, Gribble DH, Rogers QR.Plasma amino acid patterns were studied in 6 clinically normal adult horses during the course of hepatic disease induced by feeding them plants containing pyrrolizidine alkaloids. At death, there were significant (P less than 0.01) increases in glutamine, proline, tyrosine, asparagine, lysine, histidine, alanine, phenylalanine, methionine, aspartic acid, and ornithine values. There were no significant changes in glycine, valine, isoleucine tryptophan, and arginine values. There were significant (P less than 0.01) decreases in citrulline. Ammonia increased 4-fold. Alpha-Aminoadipic acid and alp...
Schryver HF, Hintz HF, Lowe JE.Absorption excretion and tissue distribution of stable Zn and 65Zn in mature ponies were studied in three experiments. In the first experiment, the metabolism of stable, dietary Zn and intravenously administered 65Zn was studied in three ponies in a 3 X 3 Latin square design. The ponies were fed a corn and beet pulp diet containing 35 mg Zn/kg or the same diet with 250 or 520 mg of supplemental Zn as ZnO. The ponies absorbed and retained more stable Zn when fed 250 mg of supplemental Zn that when fed the basal diet alone or the basal diet plus 520 mg of supplemental Zn. The ponies retained mor...
Archer M.The pasture needs for horses as compared to those for farm livestock are reviewed. The differing preferences of various types of grasses and other plants, and the patterns of grazing seen on"horse-sick" pastures, are discussed. Suggestions for practical management include frequent collection and removal of droppings, the use of grazing by cattle, adequate rest from horses and the application of cattle manure. Methods for controlling weeds and renovating horse-sick paddocks are discussed and compared to ploughing up. Finally, the place of fertilisers is considered for use on pastures for horses...
Maylin GA, Rubin DS, Lein DH.A survey of selenium and vitamin E concentrations in horses was conducted at four breeding farms in New York. There were no significant changes in mean blood selenium concentrations in horses at the three sampling dates whereas vitamin E concentrations underwent seasonal fluctuations. The mean blood selenium concentration in this survey for horses fed local feed was 7.7 microgram/dl. Horses fed commercial feed had a mean blood selenium concentration of 15.6 microgram/dl. A 0.94 correlation coefficient was found between blood glutatione peroxidase activity and blood selenium concentrations in h...
Franken P, van Beukelen P, Blok G.Two horses became ill, and one died, after being fed onions, presumably over a long period. Their intake of grass was low at the time of illness because the pasture was covered with snow. Examination of blood and urine revealed signs of severe haemolytic anaemia.
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...
Sidhu GS, Brown MA, Johnson AR.Factors contributing to the initiation of lipid oxidation in cow's and mare's milk containing high levels of polyunsaturated fatty acids were studied. Addition of H2O2 just after milking, in slight excess of the stoichiometric amounts required to destroy ascorbic acid, delayed the development of oxidized flavours in cow's milk high in linoleic acid. Hydrogen peroxide treatment followed by the addition of alpha-or gamma-tocopherols prevented lipid oxidation in cow's milk even when 0.1 mg Cu/l milk was added. When used separately in the presence of Cu these treatments were ineffective as was but...
Stamer M, Sumpf D.The live weight development of young warm-blooded stallions at the age of 0 to 30 months of life was investigated in order to derive their energy and protein requirement. The aim of the studies was the derivation of a standard curve for the course of growth. Choice of the best suited model and the corresponding calculations were one of the main investigation objects. The mathematical function developed by Janoschek provided a relatively good description of the material.
Archer M.The pasture needs for horses as compared to those for farm livestock are reviewed. The differing preferences of various types of grasses and other plants, and the patterns of grazing seen on"horse-sick" pastures, are discussed. Suggestions for practical management include frequent collection and removal of droppings, the use of grazing by cattle, adequate rest from horses and the application of cattle manure. Methods for controlling weeds and renovating horse-sick paddocks are discussed and compared to ploughing up. Finally, the place of fertilisers is considered for use on pastures for horses...
Luther DG, Cox HU, Dimopoullos GT.Fatty acid composition of erythrocytes of healthy horses was determined. Three fatty acids (C16:0, C18:0, and C18:1) were found in approximately equal quantities and comprised 72.17% of the total. Nine other fatty acids were found in small amounts. Saturated fatty acids constituted 67.2% of the total. Marked variation was demonstrated in the occurrence and distribution of fatty acids in the sterol ester, triglyceride, phospholipid, and free fatty acid fractions.
Servetnik-Chalaia GK, Mal'tseva LM.It was shown that the content of vitamins E, C, thiamine, riboflavin and niacin in mare's milk and kumyss varies depending on the season. The highest level of vitamins E, C and niacin was noted in May-June. The technological processing of mare's milk leads to the decreased content of vitamin C and niacin. Mare's milk and kumyss were found to contain dehydroascorbic acid in a considerable amount, especially in summer.
Orlov VK, Servetnik-Chalaia GK.Physicochemical properties of fat and fatty-acid composition of mare's milk and shubath (sour milk product obtained from camel's milk) depend on the season. During summer these products show a higher content of fat and increased level of polyunsaturated fatty acids, particularly in mare's milk lipids. It has been shown that in mare's milk lipids 90% is due to acids with a carbon chain of C14-18, while shubath lipids contain almost 96% of such acids.
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...
Journal of biochemistryNovember 1, 1963
Volume 54 388-397 doi: 10.1093/oxfordjournals.jbchem.a127804
JOHKE T.This research article investigates the differences in acid-soluble nucleotides in the milk of various species including cows, goats, mares, and humans through different stages of lactation, and compares the nucleotide […]
Hannant D.This study investigates severe equine asthma (sEA), a significant health risk in horses similar to human asthma, identifying latex found in riding arenas and racetracks as a potential risk factor. […]
Franken P, van Beukelen P, Blok G.Two horses became ill, and one died, after being fed onions, presumably over a long period. Their intake of grass was low at the time of illness because the pasture was covered with snow. Examination of blood and urine revealed signs of severe haemolytic anaemia.
Valberg SJ.Although horses most commonly develop exertional rhabdomyolysis, there are numerous causes for nonexertional rhabdomyolysis (nonER) that pose a serious health threat to horses. Their etiologies can be broadly categorized as toxic, genetic, inflammatory/infectious, nutritional, and traumatic and a variety of diagnostic tests are available to discern among them. This study discusses causes of nonER as well as diagnostics and treatments that are specific to each etiology. General treatment of acute rhabdomyolysis is covered in detail in the study in this issue on sporadic and recurrent exertional...
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...
Laroche N, Grimm P, Julliand S, Sorci G.Sainfoin (Onobrychis viciifolia), a polyphenol-rich plant, has shown promising anti-parasitic properties in ruminants, but results in horses are fewer and inconsistent. The mechanisms of action involved are not fully understood and different factors may influence its anti-parasitic properties. Recently, it has been shown that the effect of sainfoin depends on the horse's diet. Indeed, the inclusion of dehydrated sainfoin pellets in a high starch diet limited the rate of increase in strongyle egg shedding over a short period of time (21 days). The objective of this study was to evaluate, in viv...
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...
Sillence MN, Holt K, Li FI, Harris PA, Coyle M, Fitzgerald DM.Ecdysterone controls moulting and reproduction in insects, crustaceans, and helminths. It is also produced by many plants, probably as an insect deterrent. The steroid is not made by vertebrates but has anabolic effects in mammals and could be useful for treating sarcopenia in aged horses. However, ecdysterone is banned in horseracing and equestrian sports, and with no limit of reporting, the risk of unintended exposure to this naturally occurring prohibited substance is a concern. To explore this risk, pasture plants and hay samples were analysed for ecdysterone content, as well as samples of...
van 't Klooster AT, Hallebeek JM, Beynen AC.The diet of horses should cover the energy and nutrient requirements of these animals. The desired composition of the ration depends on its digestion in the equine gastrointestinal tract. Nutritional problems or diseases caused by incorrect composition of the ration or by incorrect feeding should be prevented. The digestion of carbohydrates, fats, and proteins in the different parts of the gastrointestinal tract is described. In addition, the recently introduced net energy and digestible protein evaluation systems for feeds, and the energy and protein requirements of horses are presented.
Francis JM, Perry EB.Horse treat packaging may be composed of materials including plastic and paper which protect the product from the environment to improve shelf life. Objectives of this research were to 1) assess the impact of packaging on shelf life of horse treats and 2) evaluate the impact of packaging on horse preferences. Three packaging treatments (control, poly, and paper) were examined at five time points over a 12 month period. Treatments were analyzed for moisture, water activity, mold, yeast, pH, and volatile organic acids. Horse preference testing evaluated first treatment sniffed, consumed, and fin...
Thompson AC, Mochal-King C.Hypoparathyroidism is an uncommon endocrine disorder in the horse characterized by a transient or permanent parathyroid hormone insufficiency. Hypoparathyroidism is associated with hypocalcemia and hyperphosphatemia, primarily presenting with clinical signs consistent with hypocalcemia. This case report describes clinical presentation and treatment of a horse with severe hypocalcemia due to primary hypoparathyroidism. A 17-year-old, 542 kg Quarter Horse gelding presented for shaking and tremors. Significant findings include generalized muscle fasciculations, synchronous diaphragmatic flutter, ...
Doreau M, Martin-Rosset W, Barlet JP.In an experiment comparing pregnant then lactating mares with dry non-pregnant mares, the changes in plasma components were studied as indicators of the metabolic utilization of energy (glucose, non-esterified fatty acids, beta-hydroxybutyrate), nitrogen (urea, proteins) or minerals (calcium, phosphorus, magnesium). The mares were fed daily 2 kg concentrate and hay ad libitum. Beta-hydroxybutyrate, magnesium and to a lesser extent glucose were the only constituents whose levels were affected within the period starting one month before and ending one month after foaling. The increase in food in...
