Topic:Feed Intake
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.
Effect of treatment with erythromycin and rifampin during the acute stages of experimentally induced equine ehrlichial colitis in ponies. Sixteen healthy ponies were inoculated IV with Ehrlichia risticii-infected P388D1 mouse monocytes. Of the 16 ponies, 15 developed clinical signs of equine ehrlichial colitis. Twenty-four hours after onset of fever (rectal temperature > 38.8 C), 7 ponies were treated with 25 mg of erythromycin stearate/kg of body weight and 10 mg of rifampin/kg, given orally every 12 hours for 5 days. The remaining 8 ill ponies served as nontreated controls. All ponies were observed for progression of clinical signs typical of equine ehrlichial colitis. Within 12 hours of initiation of treatment, 4 of the 7 ...
Increases in serum sphingosine and sphinganine and decreases in complex sphingolipids in ponies given feed containing fumonisins, mycotoxins produced by Fusarium moniliforme. Consumption of food contaminated with Fusarium moniliforme causes leucoencephalomalacia and hepatotoxicity in horses, pulmonary edema in pigs and liver cancer in rats, and has been correlated with esophageal cancer in humans. The causative agents are thought to be a family of compounds called fumonisins, which have recently been shown to be potent inhibitors of sphingosine (sphinganine) N-acyltransferase. Because inhibition at this step blocks the formation of complex sphingolipids while leading to accumulation of sphinganine, we hypothesized that exposure of animals to fumonisin-contaminated ...
Improved insulin sensitivity in hyperinsulinaemic ponies through physical conditioning and controlled feed intake. Ten hyperinsulinaemic ponies divided into conditioned (N = 5) and rested (N = 5) groups were evaluated for their insulin and glucose response following oral glucose administration at Weeks 0, 2, 4, and 6. All ponies received a controlled intake of a pelleted ration during the study. In both groups body weight had decreased from baseline by Week 4 and remained low. After 2 weeks of exercise, ponies in the conditioned group had significantly decreased insulin and glucose indices, including peak insulin response, area under the insulin curve from 0 to 210 min (TIS), and the TIS value: area under ...
Voluntary intake, milk production and plasma metabolites in nursing mares fed two different diets. Voluntary food intake, milk yield and composition, and blood metabolites were measured during the first 2 mo of lactation in draft broodmares fed diets containing either 95% hay and 5% concentrates (Diet F) or 50% hay and 50% concentrates (Diet C). Voluntary food intake was higher for mares fed Diet C than for those fed Diet F (22.9 vs. 21.4 kg dry matter in wk 4). Both diets, especially Diet C, were eaten in amounts exceeding the energy requirements. Daily milk yield in wk 4 was 26.4 kg and 23.4 kg for mares fed Diets C and F, respectively. Milk fat and protein concentrations were higher (P l...
Intake, digestion and gastrointestinal transit time in resting donkeys and ponies and exercised donkeys given ad libitum hay and straw diets. Four donkeys and four ponies maintained in climate rooms, were provided with meadow hay or barley straw supplemented with minerals and vitamins ad libitum. Both diets were given to all animals for periods of 21 days. Measurements were made during the last seven days following single doses of two non-absorbable markers (Cr-fibre and Co-EDTA). After six weeks the donkeys repeated the trial, walking 14 km and ascending 260 m five days per week. At rest ponies ate more than donkeys, however the donkeys showed a higher digestibility of dry matter (DM), organic matter (OM) and acid detergent fibre (...
Urinary excretion of theobromine in horses given contaminated pelleted food. A high pressure liquid chromatographic (HPLC) method for measuring the theobromine content in cocoa husks, pelleted food and horse urine is described. Starting with 2 ml of urine, concentrations of 500 ng/ml could easily be detected. When feed containing 38.4 mg of theobromine was given twice daily to horses for 2 1/2 days, two days were needed after the last intake before the theobromine concentrations fell below the threshold value of 2 micrograms/ml. The time at which the peak excretion rate occurred varied from 2 to 12 h after the last administration, while the excretion rate seemed to be ...
Exercise induced alterations in the serum muscle enzymes, erythrocyte potassium and plasma constituents following feed withdrawal or furosemide and sodium bicarbonate administration in the horse. Six thoroughbreds were used in each of three trials to examine the effect of potassium depletion on exercise-associated muscle damage. Horses were exercised after a control period (Treatment 1), a 72-hour fast (Treatment 2), and furosemide and sodium bicarbonate (Treatment 3). During the preexercise period, feed withdrawal for 72 hours caused decreases in body weight, plasma sodium, chloride, and serum calcium. There were no changes in plasma potassium, erythrocyte potassium, or serum creatine phosphokinase (CK) activity. Furosemide and sodium bicarbonate administration resulted in a decrease ...
Effects of a protein deficient diet and urea supplementation on lactating mares. Six lactating mares were fed either a low protein diet or the same diet with added urea ad libitum over 71 days. The quantity consumed by the mares, milk intakes of their foals, milk composition, plasma urea nitrogen (PUN), mare liveweight changes and foal growth rates were measured. The mares were unable to consume sufficient quantities of either diet to meet their nitrogen requirements and all lost weight. Adding urea to the diet significantly increased PUN in mares and foals, raised urea concentrations in the milk, decreased the mares' feed intake and significantly increased their weight lo...
[Animal nutrition for veterinarians–recent cases of clinical disorders in horses after intake of ionophore-containing feed]. Anamnesis and clinical signs of horses form five different stables after ingestion of ionophores are reported and techniques of feed examination are described. Within a few hours or days after feeding of new types or batches of concentrates horses fell ill. They showed colic-like symptoms with intense sweating and ataxia. Most of the sick animals died within a short time span. Samples of the concentrates were analysed and different types and amounts of ionophores were detected. In four cases contamination by monensin in concentrations of less than 5 mg to 679 mg/kg feed were found. One feed sa...
Cold housing effects on growth and nutrient demand of young horses. Housing temperature effects on growth, feed utilization and feed digestion of 12, 7-mo-old Standardbred colts were evaluated for 22 wk beginning in late November. Colts were assigned to one of two treatments: housed in a barn heated at 10 degrees C (warm) or housed in a barn with no external heat supply (cold). All horses were allowed outdoors for 4 h daily. Mean temperatures of the warm and cold barn from November to April were 10.9 +/- .66 and -5.2 +/- 1.72 degrees C, respectively. Hair coat weight of cold-housed colts was 1.4- to twofold (P less than .05) that of warm-housed colts from Dece...
Feed additives and contaminants as a cause of equine disease. The equine practitioner often encounters serious diagnostic and therapeutic challenges regarding the specific origin of a disease. Such challenges may occur when horses become unaccountably ill after consuming what was thought to be acceptable feed but which in fact was contaminated or contained additives intended for other species. Examples of such additives and contaminants are monensin, lasalocid, salinomycin, blister beetles, and such antimicrobics as lincomycin and clindamycin.
Ingestive behavior. In summary, horses spend 60% or more of their time eating when grazing or when feed is available free choice. Grasses are their preferred food, but they supplement the grass with herbs and woody plants. Sweetened mixtures of oats and corn are the most preferred concentrate. Horses can increase or decrease the time spent eating and amount eaten to maintain caloric intake. Their intake is stimulated by drugs such as diazepam and by the presence of other horses. Horses stop eating when gastric osmolality increases; increases in plasma osmolality, protein, and glucose accompany digestion. Foals ea...
Effect of food deprivation on D-xylose absorption test results in mares. A D-xylose absorption test was conducted on 4 healthy mares deprived of food for 12, 36, 72, and 96 hours before the test, with a 13- to 15-day adjustment period between each test. Maximal plasma concentrations after 72 and 96 hours of food deprivation were approximately 36% lower than those obtained after the 12- and 36-hour periods (P = 0.0001). Absorption curves were flatter and the decrease in plasma concentration was slower after the 72- and 96-hour periods of food deprivation. The rate of D-xylose absorption (P = 0.0108) and the initial rate of urinary excretion (P = 0.0117) were slower ...
Fiber digestion and voluntary intake in horses after adaptation to extensive large-colon resection. Each of 3 digestion trials (3 forage diets) was performed on 2 groups of horses 6 to 12 months after sham operation (group 1; n = 3) or large-colon resection (group 2; n = 5). Diets were alfalfa pellets, alfalfa hay, and grass hay. Feed and fecal analyses were performed to determine apparent digestion of dry matter, organic matter, and crude protein and true digestion of dry matter, organic matter, crude protein, total plant cell wall, hemicellulose, cellulose, and lignin. Additional fecal and metabolic variables determined were percentage of fecal water, total fecal water, metabolic organic m...
Effects of diet and feeding on postprandial serum gastrin and insulin concentration in adult horses. Gastrin is the only hormone known to stimulate secretion of hydrochloric acid. It also has trophic effects on specific parts of the mucosa of the gastrointestinal tract. Using radioimmunoassay techniques, postprandial serum gastrin and insulin concentrations were measured in six adult horses to establish effects of different diets on gastrin concentrations. Insulin concentrations were measured to provide support to the patterns of gastrin secretion because patterns of insulin secretion were already known. The horses were fed coastal bermuda hay, or twice daily 5 kg of a complete pelleted ratio...
Toxicity of field samples and Fusarium moniliforme from feed associated with equine-leucoencephalomalacia. Feed samples of corn, pelleted feed, and oats associated with equine leucoencephalomalacia (ELEM) were obtained from North Carolina, Illinois, Indiana, and Oklahoma. These samples contained a high colony density of Fusarium moniliforme Sheldon which ranged from 64 to 87% of the total fungi. Fifty-nine F. moniliforme strains were isolated. Isolates of F. moniliforme in feed samples from Illinois, Indiana, and Oklahoma were cultured on corn. The fermented corn, mixed with regular feed and fed to one-day-old ducklings, effected a high mortality coefficient (average 55%). Methanol extracts of corn...
Effects of dietary energy and phosphorus content on blood chemistry and development of growing horses. Growth and clinical biochemistry were examined over 30 wk in 42 light horse weanlings fed high-forage diets (73 to 77% alfalfa) or high-concentrate diets (63 to 65% grain and grain by-products) that were either low (.24 to .35%), normal (.68%) or high (.95 to 1.06%) in P. Body weights and blood samples were taken every 2 wk. Forage and concentrate diets contained 2.65 and 3.09 Mcal digestible energy/kg DM, respectively. Calcium and P digestibilities were highest (P less than .01) in those horses fed the low P diets, but only horses fed forage-low P diets may have absorbed insufficient P. Serum...
Energy uptake and utilization by limit- and ad libitum-fed growing horses. Eighteen weanling horses were assigned to two treatments: limited or ad libitum feed intake. Growth and feed utilization were evaluated over a 78-wk period. Ad libitum-fed horses gained 24% more (P less than .05) weight than limit-fed horses. Total BW was distributed into 57% fore and 43% hind weight and did not differ between groups regardless of dietary treatment or age. Net gain and ADG in wither height of ad libitum-fed horses exceeded (P less than .05) that of limit-fed horses over 78 wk. Ad libitum-fed horses consumed 19, 44 and 34% more digestible energy (DE) than indicated in 1978 NRC ...
Nutrient utilization by limit- and ad libitum-fed growing horses. Eighteen Quarter Horse and Paint weanling colts were assigned to two treatments, either limit or ad libitum feeding. Nutrient digestibilities of diets were evaluated between 6 and 12 mo, 12 and 18 mo and 18 and 24 mo of age. From 6 to 12 mo, energy digestibility (64 to 68%) was unaffected by feed intake level. Ad libitum-fed horses had energy digestibilities 9 to 10% greater (P less than .05) than limit-fed horses between 12 and 24 mo of age, but adjustment for DM intake removed these differences. Limit-fed, mature ponies used dietary energy similarly to growing horses from 6 to 18 mo of age, ...
Effects of diet and climate on growing horses. The effects of diet and climate were assessed in 42 light horse weanlings over 30 wk. Horses were fed diets varying in energy and phosphorus content. Diets were predominantly forage (73 to 77.5%) or concentrate (62 to 62.25%) and had 2.65 or 3.09 Mcal DE/kg DM, respectively. Horses were weighed every 14 d. Group feed intakes and climatic variables were recorded daily. Dietary phosphorus content did not affect intake or gain. Horses fed forage diets ate 18% more (P less than .001) DM than horses fed concentrate, but DE intakes did not differ. Average DE intakes, 21.5 Mcal daily, were 33% more t...
Dietary requirements and athletic performance of horses. There is no clear evidence that the chronic requirement for any non-energy yielding nutrient rises in proportion as the energy requirement increases with hard work. The need for protein, and probably that for calcium, remain a function of bodyweight daily. Some proportionality with energy may exist for certain nutrients, although the evidence has not been adduced. For example, because of an increase in both the proportion and amount of propionic acid in the volatile fatty acids of caecal contents, the tissue requirement for vitamin B12 may rise with an increase in the rate of energy metabolism...
Pyrrolizidine alkaloid-induced liver disease in horses: an early diagnosis. Nine adult horses were fed alfalfa hay cubes containing approximately 10% Senecio vulgaris until all horses had consumed approximately the same amount of toxic components of S vulgaris, pyrrolizidine alkaloids (PA). The amount of PA consumed was determined by the amount that induced clinical signs of PA toxicosis in 3 horses. The 6 other horses were given similar amounts per kilogram of body weight. An initial decrease of feed intake was observed when horses' diets were changed from alfalfa cubes to alfalfa/Senecio cubes, and feed intake was decreased further over 89 to 98 days. From 50 to 159...
Nutritional management of horses competing in 160 km races. A survey was taken of dietary management and training schedules of 54 horses competing in two 160 km endurance races. A total of 52 owners, representing 54 horses, responded to a questionnaire distributed prior to the races. Diet and training schedules were compared between horses that successfully completed the races and those that were eliminated for metabolic reasons. Horses that completed the races were 11.5 +/- 4 years old, weighed 429 +/- 4.5 kg and were ridden 61 +/- 32 km a week when training. Feed intake was reported as "free choice hay or pasture" by 34 of the respondents. Dry matter...
Relationship of cheek tooth abrasion to fluoride-induced permanent incisor lesions in livestock. Teeth from cattle, sheep, and horses that ingested various fluoride intakes and teeth from field studies of these species plus deer, elk, and bison were examined for abnormalities. Approximately 99,000 animals in 322 herds were examined for fluorosis. From field studies, 988 cattle of various ages and with different degrees of dental fluorosis were slaughtered and necropsied. The severity of fluoride-induced mottling, hypoplasia, and abnormal abrasion of paired permanent incisor teeth was correlated with abrasion of premolar and molar (cheek) teeth that form and mineralize at approximately the...
Isolation of macrocyclic and non-macrocyclic trichothecenes (stachybotrys and fusarium toxins) from the Environment of 200 III Sport Horses. Satratoxins H and G, verrucarin J, and roridin E were isolated from the bedding straw of 200 sport horses exhibiting typical symptoms of stachybotryo-toxicosis. At the same time, the oat feed consumed by the horses contained non-macrocyclicFusarium trichothecenes: T-2 toxin and diacetoxyscirpenol.
Growth and calcium metabolism in horses fed varying levels of protein. The effect of level of protein intake on growth and calcium metabolism was studied in 24 foals. Starting at four months old, the foals were fed one of three diets containing all nutrients, with the exception of protein, at levels recommended by the United States National Research Council Subcommittee on Horse Nutrition for a 12 month period. The protein levels in the three diets were 9 per cent (low protein) 14 per cent (NRC recommended level) and 20 per cent (high protein). The foals fed the low protein diet were changed to the high protein diet after 140 days when they were nine months old. ...
Enteroliths in horses. Many cases of enteroliths were reported in the nineteenth century but the number greatly decreased in the early twentieth century. However, in recent years the number of cases in certain parts of the United States such as California has greatly increased. The reasons for the increase are obscure. The intake of nitrogen, magnesium and phosphorus (the primary components of enteroliths) from water and food is likely to be a factor. Arabians may be more likely to develop enteroliths than horses of other breeds. A nidus such as a small stone is needed because a nidus has been found in every enterol...
[The digestibility of crude nutrients in horses. 2. Comparative studies on the digestive capacity of a thoroughbred horse, pony and wether]. The digestibility of the crude nutrients of 6 rations on the basis of oat, hay and wheat straw (in one case a straw-concentrate mixture as sole feed) was compared at a nutrition level of 1.0 and 1.3 resp. with adult geldings of the species "Noble Crossbreed", adult pony geldings and wethers The energy concentration of the rations varied between 424 and 585 EFUcattle/kg DM, the crude fibre content between 17 and 25% of the DM. In the studied field, a good agreement between horse and pony could be ascertained as to the digestibility of the organic matter and NFE. There are partly considerable di...