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.
Glade MJ, Krook L, Schryver HF, Hintz HF.Pony foals were injected intramuscularly with 0, 0.5, or 5.0 mg dexamethasone per 100 kg body weight daily for up to 11 months. True absorption of dietary calcium was inhibited by treatment at 18 days (57% versus 14% of intake; P less than .01) and 10 months (72% versus 55% versus 43%: P less than .01), but not at 2 or 7 months, and was independent of age and treatment related decreases in intestinal calcium binding protein activities. Uninary excretion of calcium was increased by treatment through 7 months but decreased at 10 months. Treatment for 18 days resulted in total calcium excretions ...
Stowe HD.Serum and milk samples from mares and serum samples from their foals were taken at parturition and on d 1, 2, 4, 7, 14 and 21 postpartum. The samples were assayed for retinyl (r.) palmitate, r. acetate and retinol by high performance liquid chromatography. Peak vitamin A activity in milk occurred 1 d postpartum and preceded by 3 d the maximum vitamin A activity in foal serum and the lowest vitamin A activity in the mare serum. Mare serum contained approximately a 65:35 ratio of retinol:r. palmitate and less than 1% r. acetate. Retinyl palmitate was the predominant form of vitamin A in milk unt...
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...
Silver M, Fowden AL.The production of uterine PGFM during different dietary states has been investigated in pregnant mares in late gestation. Arterial and uterine venous plasma concentrations of PGFM rose when food was withdrawn for 12-30 h and the V-A difference widened significantly. There was an inverse correlation between the rise in PGFM and the fall in plasma glucose during a fast, and a significant decrease in the A-V plasma glucose differences across the uterus. Plasma PGFM and free fatty acid concentrations before and during food withdrawal were also correlated but no uterine A-V difference in free fatty...
Aref S.A study of the migration of fourth stage larvae of the parasite Strongylus vulgaris in the intestinal arteries of the horse is presented. It is established, that the larvae migrate along the arteries in almost straight lines. It is suggested that this is primarily due to their ability to sense the curvature of the vessel wall, and not, as might have been expected, because of an ability to sense the direction of blood flow. A larva will sometimes alter its direction of motion when encountering a small off-branching artery. This behaviour suggests, that the migration of S. vulgaris larvae can be...
McKenzie RA, Gartner RJ, Blaney BJ, Glanville RJ.A supplement system for the control of equine nutritional secondary hyperparathyroidism (NSH) was evaluated on 4 farms in the Arcadia Valley of the Queensland brigalow region. Thirty-three local stock horses (of which 13 had clinical NSH and 7 were recent introductions) were grazed on buffel grass (Cenchrus ciliaris) for the 6 months from September 1979 to February 1980. Each horse was fed 1.0 kg of a mixture of ground limestone plus dicalcium phosphate (1:2) in 1.5 kg molasses each week. The pasture was hazardous during this time (total oxalate content above 0.5% and calcium: oxalate ratio be...
Ott EA, Asquith RL, Feaster JP.Forty-six Thoroughbred and Quarter Horse yearlings were used in two experiments designed to determine the amount of lysine in the concentrate necessary to promote maximum growth when fed the Coastal bermudagrass (Cynodon dactylon) hay provided at 1% body weight (BW)/day. In the first experiment, a 196-day trial, supplemental protein sources and analyses of the concentrates compared were: (1) soybean meal (SBM; 15.4% crude protein, .70% lysine); (2) SBM + .2% lysine (15.7% crude protein, .81% lysine), and (3) brewers dried grains + .2% lysine (15.9% crude protein, .59% lysine). Concentrate inta...
Naylor JM, Kenyon SJ.Horses were deprived of food but not water for a period of five days. There was a progressive decrease in circulating lymphocyte count and compromised host deference. In vitro phagocytosis of yeast fell from a mean of 97 per cent in fed horses to 78 per cent in horses deprived of food for five days. The Arthus response to intradermal challenge with allergens fell to 57 per cent of fed values. These changes indicated that food deprivation increases the susceptibility to bacterial infections; persistent anorexia in chronic bacterial infections may limit the horse's ability to cast off infection....
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.
Hintz HF, Kallfelz FA.The effects of overfeeding, calcium-phosphorus imbalance, misuse of supplements and false advertising on equine nutrition are discussed. Overfeeding is known to cause disorders in several species but, although a similar relationship has been suggested on clinical evidence, no controlled trials on horses have been reported. It has also been suggested that overfeeding is a problem only for those horses with a genetic predisposition to skeletal problems. The importance of adequate calcium and phosphorus levels has been known for many years but severe cases of calcium deficiency still occur. Clien...
Shupe JL, Eanes ED, Leone NC.Sodium fluoride (5 mg/kg of body weight) was fed for 20 months to horses with hereditary multiple exostoses (HME), a skeletal disorder that primarily affects endochondral bones during skeletal development. Rib biopsies were performed on both HME horses not fed fluoride (control) and HME horses that were fed fluoride to obtain comparable specimens for chemical analyses and x-ray diffraction. Fluoride content of the rib from a horse fed fluoride for 20 months was approximately 20 to 30 times higher than that from a control horse. Fluoride content of the bone tumors was higher than those of norma...
Lyons ET, Drudge JH, Tolliver SC.Antiparasitic activity of a micronized formulation of the benzothiazole compound, tioxidazole, at the dose rate of 11 mg/kg, was evaluated by the critical test method. Drug was given by stomach to 3 horses and on feed to 3 horses. Excellent removal activity was found for Strongylus vulgaris (100%) in 5 naturally infected horses, S edentatus (91% to 100%) in 5 horses, small strongyles (88% to 99%) in 6 horses, immature Oxyuris equi (100%) in 5 horses, and Parascaris equorum (100%) in 5 horses (a 6th horse had 10 small specimens present at necropsy). There was no measurable activity against bots...
Allison MJ, Cook HM.Rates of oxalate degradation by microbes in gastrointestinal contents from rabbits, guinea pigs, swine and a horse increased after additional of oxalate to diets. A similar response was previously observed with ruminal microbes from cattle and sheep. Bacterial that utilize oxalate for growth appear to be selected by increased levels of dietary oxalate.
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...
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...
Clarke CJ, Roeder PL, Dixon PM.A severe, advanced case of nutritional osteodystrophia fibrosa is described in a 10-year-old gelding with primary upper respiratory obstruction and chronic weight loss, which was one of a group of similarly affected horses in Ethiopia. The diagnosis was based on the clinical signs, gross lesions, histopathology and management history. The affected bones had suffered severe mineral depletion.
Sweeney RW.Malassimilation should be suspected in horses with weight loss in spite of a good appetite. Malassimilation is usually confirmed with oral glucose or D-xylose absorption tests, whereas the oral lactose tolerance test can be used to evaluate lactase deficiency in foals. Once malassimilation is confirmed, other diagnostic tests such as abdominocentesis, rectal mucosal biopsy, or exploratory laparotomy with intestinal biopsies may determine the etiology of malassimilation.
Dwivedi SK, Dey S.Fluoride possesses both essential and toxic potentials. A cross-sectional study recorded the fluoride concentrations in sera of thoroughbred horses 5y of age from 4 localities in India. A total of 628 serum samples of were analyzed for fluoride content using ion selective potentiometry. The mean serum fluoride was estimated as 0.018 +/- 0.002, 0.096 +/- 0.004, 0.16 +/- 0.008 and 0.32 +/- 0.02 ppm in horses from the eastern, central. western and southern parts of the country respectively. Although there were significant difference in fluoride concentration among horses from different zones, all...
Lotstra RJ, van den Broek J, Power T, Marr CM, Wijnberg ID.Atrial fibrillation is a common equine arrhythmia. Quinidine alone, or with digoxin are common treatments. Studies on outcome in Warmblood populations in which duration of the AF is often unknown are limited. Objective: To identify the factors that are associated with the success of full treatment cardioversion with oral medication, and establish whether there are differences in these factors between institutions. Methods: Retrospective case series using patient records of Equine University Clinic of Utrecht University and Rossdales Equine Hospital, Newmarket. Methods: Forty-nine horses treate...
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...
Osame S, Ichijo S.Seven cases of thoroughbred foals kept on a farm in the Hidaka district of Hokkaido showed bilateral thyroid enlargement from 3 or 4 months after birth. Their serum T4 levels were remarkably low, whereas T3 levels were in the normal range. Serum T4 levels were also low in the other clinically normal foals and their dams kept together. Since the iodine content in pasture soil and grass was very low, iodine deficiency was supposed to be the cause of the disease.
May SA, Hooke RE, Lees P.Chondrocytes subjected to adverse culture conditions in vitro are stimulated to produce the eicosanoid prostaglandin E2 (PGE2) and the neutral metalloproteinase stromelysin (proteoglycanase). This indicates the potential role of the chondrocyte in cartilage degeneration in equine clinical joint disease and suggests a mechanism which may be involved in the potentiation of the effects of other inflammatory mediators. Therefore, adverse conditions within the joint, such as decreased pH in an inflammatory focus and decreased access of nutrients to deeper layers of cartilage, might contribute to th...
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. […]
