Equine nutrition - AbsoluteAstronomy.com

Equine nutrition is the feeding of horse

Horse

The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...

s, ponies

Pony

A pony is a small horse . Depending on context, a pony may be a horse that is under an approximate or exact height at the withers, or a small horse with a specific conformation and temperament. There are many different breeds...

, mule

Mule

A mule is the offspring of a male donkey and a female horse. Horses and donkeys are different species, with different numbers of chromosomes. Of the two F1 hybrids between these two species, a mule is easier to obtain than a hinny...

s, donkey

Donkey

The donkey or ass, Equus africanus asinus, is a domesticated member of the Equidae or horse family. The wild ancestor of the donkey is the African Wild Ass, E...

s, and other equine

Equus (genus)

Equus is a genus of animals in the family Equidae that includes horses, donkeys, and zebras. Within Equidae, Equus is the only extant genus. Like Equidae more broadly, Equus has numerous extinct species known only from fossils. This article deals primarily with the extant species.The term equine...

s. Correct and balanced nutrition

Nutrition

Nutrition is the provision, to cells and organisms, of the materials necessary to support life. Many common health problems can be prevented or alleviated with a healthy diet....

is a critical component of proper horse care

Horse care

There are many aspects to horse care. Horses, ponies, mules, donkeys and other domesticated equids require attention from humans for optimal health and long life.-Living environment:...

.

Horses are non-ruminant

Ruminant

A ruminant is a mammal of the order Artiodactyla that digests plant-based food by initially softening it within the animal's first compartment of the stomach, principally through bacterial actions, then regurgitating the semi-digested mass, now known as cud, and chewing it again...

herbivores of a type known as a "hindgut fermenter

Hindgut fermentation

Hindgut fermentation is a digestive process seen in monogastric herbivores, animals with a simple, single-chambered stomach. Cellulose is digested with the aid of symbiotic bacteria. The microbial fermentation occurs in the digestive organs that follow the small intestine, namely the large...

." This means that horses have only one stomach, as do humans. However, unlike humans, they also have to digest plant fiber (largely cellulose

Cellulose

Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....

) that comes from grass

Grass

Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...

and hay

Hay

Hay is grass, legumes or other herbaceous plants that have been cut, dried, and stored for use as animal fodder, particularly for grazing livestock such as cattle, horses, goats, and sheep. Hay is also fed to pets such as rabbits and guinea pigs...

. Therefore, unlike ruminant

Ruminant

s, which digest fiber

Fiber

Fiber is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread.They are very important in the biology of both plants and animals, for holding tissues together....

in plant matter by use of a multichambered stomach

Stomach

The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...

, horses use microbial fermentation in a part of the digestive system known as the cecum
Cecum
The cecum or caecum is a pouch, connecting the ileum with the ascending colon of the large intestine. It is separated from the ileum by the ileocecal valve or Bauhin's valve, and is considered to be the beginning of the large intestine. It is also separated from the colon by the cecocolic...

(or caecum) to break down the cellulose.

In practical terms, horses prefer to eat small amounts of food steadily throughout the day, as they do in nature when grazing

Grazing

Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...

on pasture

Pasture

Pasture is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep or swine. The vegetation of tended pasture, forage, consists mainly of grasses, with an interspersion of legumes and other forbs...

. Although this is not always possible with modern stabling practices and human schedules that favor feeding horses twice a day, it is important to remember the underlying biology of the animal when determining what to feed, how often, and in what quantities.

The digestive system of the horse is somewhat delicate. Horses are unable to regurgitate

Regurgitation (digestion)

Regurgitation is the expulsion of material from the mouth, pharynx, or esophagus, usually characterized by the presence of undigested food or blood.Regurgitation is used by a number of species to feed their young...

food, except from the esophagus

Esophagus

The esophagus is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. During swallowing, food passes from the mouth through the pharynx into the esophagus and travels via peristalsis to the stomach...

. Thus, if they overeat or eat something poisonous, vomiting is not an option. They also have a long, complex large intestine

Large intestine

The large intestine is the third-to-last part of the digestive system — — in vertebrate animals. Its function is to absorb water from the remaining indigestible food matter, and then to pass useless waste material from the body...

and a balance of beneficial microbes in their cecum

Cecum

The cecum or caecum is a pouch, connecting the ileum with the ascending colon of the large intestine. It is separated from the ileum by the ileocecal valve or Bauhin's valve, and is considered to be the beginning of the large intestine. It is also separated from the colon by the cecocolic...

that can be upset by rapid changes in feed. Because of these factors, they are very susceptible to colic

Horse colic

Colic in horses is defined as abdominal pain, but it is a clinical sign rather than a diagnosis. The term colic can encompass all forms of gastrointestinal conditions which cause pain as well as other causes of abdominal pain not involving the gastrointestinal tract. The most common forms of colic...

, which is a leading cause of death in horses. Therefore, horses require clean, high-quality feed, provided at regular intervals, and may become ill if subjected to abrupt changes in their diets. Horses are also sensitive to molds and toxins. For this reason, they must never be fed contaminated fermentable materials such as lawn clippings. Fermented silage

Silage

Silage is fermented, high-moisture fodder that can be fed to ruminants or used as a biofuel feedstock for anaerobic digesters. It is fermented and stored in a process called ensiling or silaging, and is usually made from grass crops, including corn , sorghum or other cereals, using the entire...

or "haylage" is fed to horses in some places; however, contamination or failure of the fermentation process that allows any mold or spoilage may be toxic.

The digestive system

Horses and other members of the genus Equus
Equus (genus)
Equus is a genus of animals in the family Equidae that includes horses, donkeys, and zebras. Within Equidae, Equus is the only extant genus. Like Equidae more broadly, Equus has numerous extinct species known only from fossils. This article deals primarily with the extant species.The term equine...

are adapted by evolutionary biology to eating small amounts of the same kind of food all day long. In the wild, horses ate prairie

Prairie

Prairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type...

grasses in semi-arid regions and traveled significant distances each day in order to obtain adequate nutrition. Therefore, their digestive system was made to work best with a small but steady flow of food that does not change much from day to day.

Chewing and swallowing

Digestion begins in the mouth

Mouth

The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....

. First, the animal selects pieces of forage

Forage

Forage is plant material eaten by grazing livestock.Historically the term forage has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used more loosely to include similar plants cut for fodder and carried to the animals, especially...

and picks up finer foods, such as grain

GRAIN

GRAIN is a small international non-profit organisation that works to support small farmers and social movements in their struggles for community-controlled and biodiversity-based food systems. Our support takes the form of independent research and analysis, networking at local, regional and...

, with sensitive, prehensile, lip

Lip

Lips are a visible body part at the mouth of humans and many animals. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech...

s. The front teeth

Horse teeth

Horses' teeth are often used to estimate the animal's age, hence the sayings "long in the tooth", "straight from the horse's mouth" and "Don't look a gift horse in the mouth".- Types of teeth :At five years of age a horse has between 36 and 44 teeth...

of the horse, called incisor

Incisor

Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...

s, nip off forage

Forage

, and food is ground up for swallowing by the premolar

Premolar

The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered as a 'transitional tooth' during chewing, or...

s and molars.

The esophagus

Esophagus

carries food to the stomach. The esophagus enters the stomach at an acute angle, creating a one-way valve, with a powerful sphincter

Sphincter

A sphincter is an anatomical structure, or a circular muscle, that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning...

mechanism at the gastroesophageal junction, which is why horses cannot vomit. The esophagus is also the area of the digestive tract where horses may suffer from choke

Choke (horse)

Choke is a condition in horses in which the esophagus is blocked, usually by food material. Although the horse is still able to breathe, it is unable to swallow, and may become severely dehydrated. A secondary condition, aspiration pneumonia, may also develop if food material and saliva accumulate...

. (see Illnesses related to improper feeding below)

The stomach and small intestine

Horses have a small stomach

Stomach

for their size, which limits the amount of feed that can be taken in at one time. The average sized horse has a stomach with a capacity of only 4 gallons (15.1 l), and works best when it contains about 2 gallons (7.6 l). One reason continuous foraging or several small feedings per day are better than one or two large meals is because the stomach begins to empty when it is two-thirds full, whether the food in the stomach is processed or not.

The small intestine

Small intestine

The small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to...

is 50 to 70 ft (15.2 to 21.3 m) long and holds 10 gallons (37.9 l) to 12 gallons (45.4 l). This is the major digestive organ where 50 to 70 percent of all nutrients are absorbed into the bloodstream. Bile

Bile

Bile or gall is a bitter-tasting, dark green to yellowish brown fluid, produced by the liver of most vertebrates, that aids the process of digestion of lipids in the small intestine. In many species, bile is stored in the gallbladder and upon eating is discharged into the duodenum...

from the liver

Liver

The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

acts here, combined with enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

s from the pancreas

Pancreas

The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...

and small intestine itself. Equids do not have a gall bladder, so bile flows constantly, an adaptation to a slow but steady supply of food, and another reason for providing fodder

Fodder

Fodder or animal feed is any agricultural foodstuff used specifically to feed domesticated livestock such as cattle, goats, sheep, horses, chickens and pigs. Most animal feed is from plants but some is of animal origin...

to horses in several small feedings.

The cecum and large intestine

The cecum

Cecum

is the first section of the large intestine

Large intestine

. It is also known as the "water gut" or "hind gut." It is a blind-ended pouch, about 4 feet (1.2 m) long that holds 7 gallons (26.5 l) to 8 gallons (30.3 l). The small intestine opens into the cecum, and the cellulose

Cellulose

Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....

plant fiber

Fiber

in the food is fermented

Fermentation (biochemistry)

Fermentation is the process of extracting energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound. In contrast, respiration is where electrons are donated to an exogenous electron acceptor, such as oxygen,...

by microbes for approximately seven hours. The fermented material leaves the cecum through another orifice and passes to the large colon. The microbes in the cecum produce vitamin K

Vitamin K

Vitamin K is a group of structurally similar, fat soluble vitamins that are needed for the posttranslational modification of certain proteins required for blood coagulation and in metabolic pathways in bone and other tissue. They are 2-methyl-1,4-naphthoquinone derivatives...

, B-complex vitamins, proteins, and fatty acids. The reason horses must have their diets changed slowly is so the microbes in the cecum are able to modify and adapt to the different chemical structure of new feedstuffs. Too abrupt a change in diet can cause colic

Horse colic

, because new materials are not properly digested.
The large colon

Colon (anatomy)

The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...

, small colon, and rectum

Rectum

The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...

make up the remainder of the large intestine

Large intestine

. The large colon is 10 to 12 ft (3 to 3.7 m) long and holds up to 20 gallons (75.7 l) of semi-liquid matter. Its main purpose is to absorb carbohydrates which were broken down from cellulose in the cecum. Due to its many twists and turns, it is a common place for a type of horse colic

Horse colic

called an impaction. The small colon is also 10 to 12 ft (3 to 3.7 m) long, holds about 5 gallons (18.9 l), is the area where the majority of water is absorbed, and where fecal balls are formed. The rectum

Rectum

The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...

is about one foot long, and acts as a holding chamber for waste, which is then expelled from the body via the anus

Anus

The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...

Nutrients

Like all animals, equines require five main classes of nutrients to survive: water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

, energy (primarily in the form of fat

Fat

Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...

s and carbohydrates), protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

s, vitamin

Vitamin

A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on...

s, and minerals.

Water

makes up between 62-68% of a horse's body weight and is essential for life. Horses can only live a few days without water, becoming dangerously dehydrated if they lose 8-10% of their natural body water. Therefore, it is critically important for horses to have access to a fresh, clean, and adequate supply of water.

An average 1000 lb (453.6 kg) horse drinks 10 gallons (37.9 l) to 12 gallons (45.4 l) of water per day, more in hot weather, when eating dry forage such as hay

Hay

, or when consuming high levels of salt, potassium, and magnesium. Horses drink less water in cool weather or when on lush pasture

Pasture

, which has a higher water content. When under hard work, or if a mare

Mare (horse)

A mare is an adult female horse or other equine.In most cases, a mare is a female horse over the age of three, and a filly is a female horse age three and younger. However, in Thoroughbred horse racing, a mare is defined as a female horse more than four years old; in harness racing a mare is a...

is lactating, water requirements may be as much as four times greater than normal. Though they need a great deal of water, horses spend very little time drinking; usually 1–8 minutes a day, spread out in 2-8 episodes.

Water plays an important part in digestion. The forages and grains horses eat are mixed with saliva in the mouth to make a moist bolus that can be easily swallowed. Therefore, horses produce up to 10 gallons (37.9 l) or 85 lb. of saliva

Saliva

Saliva , referred to in various contexts as spit, spittle, drivel, drool, or slobber, is the watery substance produced in the mouths of humans and most other animals. Saliva is a component of oral fluid. In mammals, saliva is produced in and secreted from the three pairs of major salivary glands,...

per day.

Energy nutrients and protein

Nutritional sources of energy are fat

Fat

and carbohydrate

Carbohydrate

A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...

s. Protein

Protein

is a critical building block for muscles and other tissues. Horses that are heavily exercised, growing, pregnant or lactating need increased energy and protein in their diet. However, if a horse has too much energy in its diet and not enough exercise, it can become too high-spirited and difficult to handle.

Fat

Fat

exists in low levels in plants and can be added to increase the energy density of the diet. Fat has 9 megacalories (37.7 MJ) per kilogram of energy, which is 2.25 times that of any carbohydrate source. Because equids have no gall bladder to store large quantities of bile

Bile

, which flows continuously from the liver

Liver

directly into the small intestine, fat

Fat

, though a necessary nutrient

Nutrient

A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy...

, is difficult for them to digest and utilize in large quantities. However, they are able to digest a greater amount of fat than can cattle

Cattle

Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...

. Horses benefit from up to 8% fat in their diets, but more does not always provide a visible benefit. Horses can only have 15-20% fat in their diet without the risk of developing diarrhea

Diarrhea

Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

.

Carbohydrates, the main energy source in most rations, are usually fed in the form of hay

Hay

, grass

Grass

, and grain

GRAIN

. Soluble carbohydrates such as starch

Starch

Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...

es and sugar

Sugar

Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...

s are readily broken down to glucose

Glucose

Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...

in the small intestine and absorbed. Insoluble carbohydrates, such as fiber (cellulose), are not digested by the horse's own enzymes, but are fermented by microbes in the cecum and large colon to break down and release their energy sources, volatile fatty acid

Fatty acid

In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...

s.

Soluble carbohydrates are found in nearly every feed source; corn

Maize

Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...

has the highest amount, then barley

Barley

Barley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...

and oats

OATS

OATS - Open Source Assistive Technology Software - is a source code repository or "forge" for assistive technology software. It was launched in 2006 with the goal to provide a one-stop “shop” for end users, clinicians and open-source developers to promote and develop open source assistive...

. Forage

Forage

s normally have only 6-8% soluble carbohydrate, but under certain conditions can have up to 30%. Sudden ingestion of large amounts of starch or high sugar feeds can cause at the least an indigestion colic

Horse colic

, and at the worst potentially fatal colitis

Colitis

In medicine, colitis refers to an inflammation of the colon and is often used to describe an inflammation of the large intestine .Colitides may be acute and self-limited or chronic, i.e...

or laminitis

Laminitis

Laminitis is a disease that affects the feet of ungulates. It is best known in horses and cattle. Symptoms include lameness, and increased temperature in the hooves...

.

Protein

Protein

is used in all parts of the body, especially muscle

Muscle

Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...

, blood

Blood

Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

, hormone

Hormone

A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...

s, hooves

Horse hoof

A horse hoof is a structure surrounding the distal phalanx of the 3rd digit of each of the four limbs of Equus species, which is covered by complex soft tissue and keratinised structures...

, and hair cells. The main building blocks of protein are amino acid

Amino acid

Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...

s. Alfalfa

Alfalfa

Alfalfa is a flowering plant in the pea family Fabaceae cultivated as an important forage crop in the US, Canada, Argentina, France, Australia, the Middle East, South Africa, and many other countries. It is known as lucerne in the UK, France, Australia, South Africa and New Zealand, and known as...

and other legumes in hay

Hay

are good sources of protein that can be easily added to the diet. Most adult horses only require 8-10% protein in their diet; however, higher protein is important for lactating mares and young growing foal

Foal

A foal is an equine, particularly a horse, that is one year old or younger. More specific terms are colt for a male foal and filly for a female foal, but these terms are used until the horse is age three or four. When the foal is nursing from its dam , it may also be called a suckling...

Vitamins and minerals

Horses that are not subjected to hard work or extreme conditions usually have more than adequate amounts of vitamins in their diet if they are receiving fresh, green, leafy forages. Sometimes a vitamin supplement is needed when feeding low-quality hay, if a horse is under stress (illness, traveling, showing, racing, and so on), or not eating well. Grain has a different balance of nutrients than forage, and so requires specialized supplementation to prevent an imbalance of vitamins and minerals.

Minerals are required for maintenance and function of the skeleton

Skeleton

The skeleton is the body part that forms the supporting structure of an organism. There are two different skeletal types: the exoskeleton, which is the stable outer shell of an organism, and the endoskeleton, which forms the support structure inside the body.In a figurative sense, skeleton can...

, nerve

Nerve

A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...

s, and muscles. These include calcium

Calcium

Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

, phosphorus

Phosphorus

Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...

, sodium

Sodium

Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

, potassium

Potassium

Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...

, and chloride

Chloride

The chloride ion is formed when the element chlorine, a halogen, picks up one electron to form an anion Cl−. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. The chloride ion, and its salts such as sodium chloride, are very soluble in water...

, and are commonly found in most good-quality feeds. Horses also need trace minerals such as magnesium

Magnesium

Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...

, selenium

Selenium

Selenium is a chemical element with atomic number 34, chemical symbol Se, and an atomic mass of 78.96. It is a nonmetal, whose properties are intermediate between those of adjacent chalcogen elements sulfur and tellurium...

, copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

, zinc

Zinc

Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

, and iodine

Iodine

Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....

. Normally, if adult animals at maintenance levels are consuming fresh hay or are on pasture, they will receive adequate amounts of minerals in their diet, with the exception of sodium chloride (salt

Salt

In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

), which needs to be provided, preferably free choice. Some pastures are deficient in certain trace minerals, including selenium, zinc, and copper, and in such situations, health problems, including deficiency diseases, may occur if horses' trace mineral intake is not properly supplemented.

Calcium and phosphorus are needed in a specific ratio of between 1:1 and 2:1. Adult horses can tolerate up to a 5:1 ratio, foals no more than 3:1. A total ration with a higher ratio of phosphorus than calcium is to be avoided. Over time, imbalance will ultimately lead to a number of possible bone-related problems such as osteoporosis

Osteoporosis

Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...

.

Foal

Foal

s and young growing horses through their first three to four years have special nutritional needs and require feeds that are balanced with a proper calcium:phosphorus ratio and other trace minerals. A number of skeletal

Skeleton

problems may occur in young animals with an unbalanced diet. Hard work increases the need for minerals; sweating depletes sodium, potassium, and chloride from the horse’s system. Therefore, supplementation with electrolyte

Electrolyte

In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....

s may be required for horses in intense training, especially in hot weather.

Types of feed

Equid

Equus (genus)

s can consume approximately 2-2.5% of their body weight in dry feed each day. Therefore, a 1000 lb (453.6 kg) adult horse could eat up to 25 lb (11.3 kg) of food. Foal

Foal

s less than six months of age eat 2-4% of their weight each day.

Solid feeds are placed into three categories: forages (such as hay and grass), concentrates (including grain or pelleted rations), and supplements (such as prepared vitamin or mineral pellets). Equine nutritionists recommend that 50% or more of the animal's diet by weight should be forage

Forage

s. If a horse is working hard and requires more energy, the use of grain

GRAIN

is increased and the percentage of forage decreased so that the horse obtains the energy content it needs for the work it is performing. However, forage amount should never go below 1% of the horse's body weight per day.

Forages

Forage

s, also known as "roughage," are plant materials classified as legumes or grass

Grass

es, found in pasture

Pasture

s or in hay

Hay

. Often, pastures and hayfields will contain a blend of both grasses and legumes. Nutrients available in forage vary greatly with maturity of the grasses, fertilization, management, and environmental conditions. Grasses are tolerant of a wide range of conditions and contain most necessary nutrients. Some commonly used grasses include timothy

Timothy-grass

Timothy-grass , is an abundant perennial grass native to most of Europe except for the Mediterranean region. It grows to 50–150 cm tall, with leaves up to 45 cm long and 1 cm broad. The flowerhead is 7–15 cm long and 8–10 mm broad, with densely packed spikelets...

, brome

Bromus

Bromus is a large genus of the grass family . Estimates in the scientific literature of the number of species have ranged from 100 to 400, but plant taxonomists currently recognize around 160–170 species...

, fescue

Fescue

Festuce is a genus of about 300 species of perennial tufted grasses, belonging to the grass family Poaceae . The genus has a cosmopolitan distribution, although the majority of the species are found in cool temperate areas...

, coastal Bermuda

Cynodon

Cynodon is a genus of nine species of grasses, native to warm temperate to tropical regions of the Old World. The genus as a whole as well as its species are commonly known as Bermuda Grass or Dog's Tooth Grass.-Species:...

, orchard grass, and Kentucky bluegrass

Smooth Meadow-grass

Poa pratensis, commonly known as Kentucky Bluegrass, Smooth Meadow-grass, or Common Meadow-grass, is a perennial species of grass native to Europe, Asia, and northern Africa.-General description:...

. Another type of forage sometimes provided to horses is beet pulp

Beet pulp

Beet pulp is a byproduct from the processing of sugar beet which is used as fodder for horses and other livestock. It is supplied either as dried flakes or as compressed pellets, but when fed to horses it is usually soaked in water first.-Composition:...

, a byproduct left over from the processing of sugar beet

Sugar beet

Sugar beet, a cultivated plant of Beta vulgaris, is a plant whose tuber contains a high concentration of sucrose. It is grown commercially for sugar production. Sugar beets and other B...

s, which is high in energy as well as fiber.

Legumes such as clover

Clover

Clover , or trefoil, is a genus of about 300 species of plants in the leguminous pea family Fabaceae. The genus has a cosmopolitan distribution; the highest diversity is found in the temperate Northern Hemisphere, but many species also occur in South America and Africa, including at high altitudes...

or alfalfa

Alfalfa

are usually higher in protein

Protein

, calcium

Calcium

, and energy than grasses. However, they require warm weather and good soil to produce the best nutrients. Legume hays are generally higher in protein than the grass hays. They are also higher in minerals, particularly calcium, but have an incorrect ratio of calcium to phosphorus. Because they are high in protein, they are very desirable for growing horses or those subjected to very hard work, but the calcium:phosphorus ratio must be balanced by other feeds to prevent bone abnormalities.

Hay

Hay

is a dried mixture of grass

Grass

es and legumes. It is cut in the field and then dried and baled for storage. Hay is most nutritious when it is cut early on, before the seed heads are fully mature and before the stems of the plants become tough and thick. Hay that is very green can be a good indicator of the amount of nutrients in the hay; however, color is not the sole indicator of quality—smell and texture are also important. Hay can be analyzed by many laboratories and that is the most reliable way to tell the nutritional values it contains.

Hay, particularly alfalfa, is sometimes compressed into pellets or cubes. Processed hay can be of more consistent quality and is more convenient to ship and to store. It is also easily obtained in areas that may be suffering localized hay shortages. However, these more concentrated forms can be overfed and horses are somewhat more prone to choke

Choke (horse)

on them. On the other hand, hay pellets and cubes can be soaked until they break apart into a pulp or thick slurry, and in this state are a very useful source of food for horses with tooth

Horse teeth

problems such as dental disease, tooth loss due to age, or structural anomalies.

Haylage, also known as Round bale silage is a term for grass sealed in airtight plastic bags, a form of forage that is frequently fed in the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

and continental Europe, but is not often seen in the United States. Because haylage is a type of silage

Silage

, hay stored in this fashion must remain completely sealed in plastic, as any holes or tears can stop the preservation properties of fermentation and lead to mold or spoilage. Rodents chewing through the plastic can also spoil the hay introducing contamination to the bale. If a rodent dies inside the plastic, the subsequent botulism

Botulism

Botulism also known as botulinus intoxication is a rare but serious paralytic illness caused by botulinum toxin which is metabolic waste produced under anaerobic conditions by the bacterium Clostridium botulinum, and affecting a wide range of mammals, birds and fish...

toxins released can contaminate the entire bale.

Sometimes, straw

Straw

Straw is an agricultural by-product, the dry stalks of cereal plants, after the grain and chaff have been removed. Straw makes up about half of the yield of cereal crops such as barley, oats, rice, rye and wheat. It has many uses, including fuel, livestock bedding and fodder, thatching and...

or chaff

Chaff

Chaff is the dry, scaly protective casings of the seeds of cereal grain, or similar fine, dry, scaly plant material such as scaly parts of flowers, or finely chopped straw...

is fed to animals. However, this is roughage with little nutritional value other than providing fiber. It is sometimes used as a filler; it can slow down horses who eat their grain too fast, or it can provide additional fiber when the horse must meet most nutritional needs via concentrated feeds. Straw is more often used as a bedding in stalls to absorb wastes.

Concentrates

Grains

Whole or crushed grain

GRAIN

s are the most common form of concentrated feed, sometimes referred to generically as "oats" or "corn" even if those grains are not present, also sometimes called straights in the UK.

Oat

Oat

The common oat is a species of cereal grain grown for its seed, which is known by the same name . While oats are suitable for human consumption as oatmeal and rolled oats, one of the most common uses is as livestock feed...

s are the most popular grain

GRAIN

for horses. Oats have a lower digestible energy value and higher fiber content than most other grains. They form a loose mass in the stomach that is well suited to the equine digestive system. They are also more palatable and digestible than other grains.

Corn

Maize

(USA), or maize (British English), is the second most palatable grain. It provides twice as much digestible energy as an equal volume of oats and is low in fiber. Because of these characteristics, it is easy to over-feed corn, causing obesity

Obesity

Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...

, so horses are seldom fed corn all by itself. Nutritionists caution horse owners that moldy corn is poisonous if fed to horses.

Barley

Barley

is also fed to horses, but needs to be processed to crack the seed hull and allow easier digestibility. It is frequently fed in combination with oats and corn, a mix informally referred to by the acronym "COB" (for Corn, Oats and Barley).

Wheat

Wheat

Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...

is generally not used as a concentrate. However, wheat bran is sometimes added to the diet of a horse for supplemental nutrition, usually moistened and in the form of a bran mash. Wheat bran is high in phosphorus, so must be fed carefully so that it does not cause an imbalance in the Ca:P ratio of a ration. Once touted for a laxative effect, this use of bran is now considered unnecessary, as horses, unlike humans, obtain sufficient fiber in their diets from other sources.

Mixes and Pellets

Many feed manufacturers combine various grains and add additional vitamin and mineral supplements to create a complete premixed feed that is easy for owners to feed and of predictable nutritional quality. Some of these prepared feeds are manufactured in pelleted form, others retain the grains in their original form. In many cases molasses

Molasses

Molasses is a viscous by-product of the processing of sugar cane, grapes or sugar beets into sugar. The word molasses comes from the Portuguese word melaço, which ultimately comes from mel, the Latin word for "honey". The quality of molasses depends on the maturity of the sugar cane or sugar beet,...

is used as a binder to keep down dust and for increased palatability. Grain mixes with added molasses are usually called "sweet feed" in the United States and "coarse mix" in the United Kingdom

United Kingdom

. Pelleted or extruded feeds (sometimes referred to as "nuts" in the UK) may be easier to chew and result in less wasted feed. Horses generally eat pellets as easily as grain. However, pellets are also more expensive, and even "complete" rations do not eliminate the necessity for forage.

Supplements

The average modern horse on good hay or pasture with light work usually does not need supplements; however, horses subjected to stress due to age, intensive athletic work, or reproduction may need additional nutrition. Extra fat and protein are sometimes added to the horse's diet, along with vitamin and mineral supplements. There are hundreds, if not thousands of commercially prepared vitamin and mineral supplements on the market, many tailored to horses with specialized needs.

Soybean

Soybean

The soybean or soya bean is a species of legume native to East Asia, widely grown for its edible bean which has numerous uses...

meal is a common protein supplement, and averages about 44% crude protein. The protein in soybean meal is high-quality, with the proper ratio of dietary essential amino acid

Amino acid

s for equids. Cottonseed meal, Linseed meal, and peanut meal are also used, but are not as common.

Vegetable oil is a common fat source added to a ration. Corn oil

Corn oil

Corn oil is oil extracted from the germ of corn . Its main use is in cooking, where its high smoke point makes refined corn oil a valuable frying oil. It is also a key ingredient in some margarines. Corn oil is generally less expensive than most other types of vegetable oils. One bushel of corn...

is particularly popular, but other oils are used as well. Rice bran is a very good fat supplement that contains 20% fat as well as fiber and other nutrients. Flax

Flax

Flax is a member of the genus Linum in the family Linaceae. It is native to the region extending from the eastern Mediterranean to India and was probably first domesticated in the Fertile Crescent...

seed is another good source of fat, though it must be ground up for horses to digest it. Some commercial feed manufacturers now make products containing both flaxseed and rice bran.

Feeding practices

Most horses only need quality forage, water, and a salt or mineral block. Grain or other concentrates are often not necessary. But, when grain or other concentrates are fed, quantities must be carefully monitored. To do so, horse feed is measured by weight, not volume. For example, 1 lb (0.45359237 kg) of oats has a different volume than 1 lb (0.45359237 kg) of corn. When continuous access to feed is not possible, it is more consistent with natural feeding behavior to provide three small feedings per day instead of one or two large ones. However, even two daily feedings is preferable to only one. To gauge the amount to feed, a weight tape can be used to provide a reasonably accurate estimate of a horse's weight. The tape measures the circumference of the horse's barrel

Horse anatomy

Equine anatomy refers to the gross and microscopic anatomy of horses and other equids, including donkeys, and zebras. While all anatomical features of equids are described in the same terms as for other animals by the International Committee on Veterinary Gross Anatomical Nomenclature in the book...

, just behind the withers and elbows, and the tape is calibrated to convert circumference into approximate weight.

Actual amounts fed vary by the size of the horse, the age of the horse, the climate, and the work to which the animal is put. In addition, genetic

Genetics

Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

factors play a role. Some animals are naturally easy keeper

Easy keeper

An easy keeper, easy doer or good doer is a livestock animal that can live on relatively little food. The opposite of an easy keeper is a hard keeper , an animal that is prone to be too thin and has difficulty maintaining adequate weight.Easy keepers tend to be found most often in breeds...

s (good doers), which means that they can thrive on small amounts of food and are prone to obesity

Obesity

and other health problems if overfed. Others are hard keeper

Hard keeper

A hard keeper or poor doer is a horse or other livestock animal that is naturally prone to be thin, will lose weight quickly, and has difficulty gaining weight....

s (poor doers), meaning that they are prone to be thin and require considerably more food to maintain a healthy weight.

Veterinarian

Veterinarian

A veterinary physician, colloquially called a vet, shortened from veterinarian or veterinary surgeon , is a professional who treats disease, disorder and injury in animals....

s are usually a good source for recommendations on appropriate types and amounts of feed for a specific horse. Animal nutritionists are also trained in how to develop equine rations and make recommendations. There are also numerous books written on the topic. Feed manufacturers usually offer very specific guidelines for how to select and properly feed products from their company, and in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, the local office of the Cooperative Extension Service

Cooperative extension service

The Cooperative Extension Service, also known as the Extension Service of the USDA, is a non-formal educational program implemented in the United States designed to help people use research-based knowledge to improve their lives. The service is provided by the state's designated land-grant...

can provide educational materials and expert recommendations.

Feeding forages

Equids always require forage. When possible, nutritionists recommend it be available at all times, at least when doing so does not overfeed the animal and lead to obesity

Obesity

. It is safe to feed a ration that is 100% forage (along with water and supplemental salt), and any feed ration should be at least 50% forage. Hay with alfalfa or other legumes has more concentrated nutrition and so is fed in smaller amounts than grass hay, though many hays have a mixture of both types of plant.

When beet pulp

Beet pulp

is fed, a ration of 2 lb (0.90718474 kg) to 5 lb (2.3 kg) is usually soaked in water for 3 to 4 hours prior to feeding in order to make it more palatable, and to minimize the risk of choke and other problems. It is usually soaked in a proportion of one part beet pulp to two parts water. Beet pulp is usually fed in addition to hay, but occasionally is a replacement for hay when fed to very old horses who can no longer chew properly. It is available in both pelleted and shredded form, pellets must be soaked significantly longer than shredded beet pulp.

Some pelleted rations are designed to be a "complete" feed that contains both hay and grain, meeting all the horse's nutritional needs. However, even these rations should have some hay or pasture provided, a minimum of a half-pound of forage for every 100 lb (45.4 kg) of horse, in order to keep the digestive system functioning properly and to meet the horse's urge to graze.

When horses graze under natural conditions, they may spend up to 18 hours per day doing so. However, on modern irrigated pastures, they may have their nutritional needs for forage met in as little as three hours per day, depending on the quality of grass available.

Recent studies address the level of various non-structural carbohydrates (NSC), such as fructan

Fructan

A fructan is a polymer of fructose molecules. Fructans with a short chain length are known as fructooligosaccharides, whereas longer chain fructans are termed inulins...

, in forages. Too high an NSC level causes difficulties for animals prone to laminitis

Laminitis

Laminitis is a disease that affects the feet of ungulates. It is best known in horses and cattle. Symptoms include lameness, and increased temperature in the hooves...

or equine polysaccharide storage myopathy

Equine polysaccharide storage myopathy

EPSM or Equine Polysaccharide Storage Myopathy is a muscle disease most commonly associated with heavy horse breeds. Common heavy horse breeds in the United States include the Clydesdale, Shire, Belgian Draft or Belgian, Suffolk Punch and Percheron. EPSM may also occur in the American Quarter...

(EPSM). NSC cannot be determined by looking at forage, but hay and pasture grasses can be tested for NSC levels.

Feeding concentrates

Concentrates, when fed, are recommended to be provided in quantities no greater than 1% of a horse's body weight per day, and preferably in two or more feedings. If a ration needs to contain a higher percent of concentrates, such as that of a race horse

Horse racing

Horse racing is an equestrian sport that has a long history. Archaeological records indicate that horse racing occurred in ancient Babylon, Syria, and Egypt. Both chariot and mounted horse racing were events in the ancient Greek Olympics by 648 BC...

, bulky grains such as oats should be used as much as possible; a loose mass of feed helps prevent impaction colic. Peptic ulcer

Peptic ulcer

A peptic ulcer, also known as PUD or peptic ulcer disease, is the most common ulcer of an area of the gastrointestinal tract that is usually acidic and thus extremely painful. It is defined as mucosal erosions equal to or greater than 0.5 cm...

s are linked to a too-high concentration of grain in the diet, particularly noticed in modern racehorses, where some studies show such ulcers affecting up to 90% of all race horses.

In general, the portion of the ration that should be grain or other concentrated feed is 0-10% grain for mature idle horses; between 20-70% for horses at work, depending on age, intensity of activity, and energy requirements. Concentrates should not be fed to horses within one hour before or after a heavy workout. Concentrates also need to be adjusted to level of performance. Not only can excess grain and inadequate exercise lead to behavior problems, it may also trigger serious health problems that include Equine Exertional Rhabdomyolysis

Equine Exertional Rhabdomyolysis

Equine exertional rhabdomyolysis is a syndrome that damages the muscle tissue in horses...

, or "tying up," in horses prone to the condition. Another possible risk are various forms of horse colic

Horse colic

. A relatively uncommon, but usually fatal concern is colitis-X

Colitis-X

Colitis X, equine colitis X or peracute toxemic colitis is a catchall term for various fatal forms of acute or peracute colitis found in horses, but particularly a fulminant colitis where clinical signs include sudden onset of severe diarrhea, abdominal pain, shock, and dehydration. Death is...

, which may be triggered by excess protein and lack of forage in the diet that allows for the multiplication of clostridial

Clostridium

Clostridium is a genus of Gram-positive bacteria, belonging to the Firmicutes. They are obligate anaerobes capable of producing endospores. Individual cells are rod-shaped, which gives them their name, from the Greek kloster or spindle...

organisms, and is exacerbated by stress.

Access to water

Horses normally require free access to all the fresh, clean water

Water

they want, and to avoid dehydration, should not be kept from water longer than four hours at any one time. However, water may need to be temporarily limited in quantity when a horse is very hot after a heavy workout. As long as a hot horse continues to work, it can drink its fill at periodic intervals, provided that common sense is used and that an overheated horse is not forced to drink from extremely cold water sources. But when the workout is over, a horse needs to be cooled out and walked for 30–90 minutes before it can be allowed all the water it wants at one time. However, dehydration is also a concern, so some water needs to be offered during the cooling off process. A hot horse will properly rehydrate while cooling off if offered a few swallows of water every three to five minutes while being walked. Sometimes the thirst mechanism does not immediately kick in following a heavy workout, which is another reason to offer periodic refills of water throughout the cooling down period.

Even a slightly dehydrated horse is at higher risk of developing impaction colic

Horse colic

. Additionally, dehydration can lead to weight loss because the horse cannot produce adequate amounts of saliva, thus decreasing the amount of feed and dry forage consumed. Thus, it is especially important for horse owners to encourage their horses to drink when there is a risk of dehydration; when horses are losing a great deal of water in hot weather due to strenuous work, or in cold weather due to horses' natural tendency to drink less when in a cold environment. To encourage drinking, owners may add electrolytes to the feed, additives to make the water especially palatable (such as apple juice), or, when it is cold, to warm the water so that it is not at a near-freezing temperature.

Special feeding issues for Ponies

Ponies

Pony

and miniature horse

Miniature horse

Miniature horses are found in many nations, particularly in Europe and the Americas. The designation of miniature horse is determined by the height of the animal, which, depending on the particular breed registry involved, is usually less than as measured at the last hairs of the mane, which are...

s are usually easy keeper

Easy keeper

s and need less feed than full-sized horses. This is not only because they are smaller, but also, because they evolved under harsher living conditions than horses, they use feed more efficiently. Ponies easily become obese

Obesity

from overfeeding and are at high risk for colic and, especially, laminitis

Laminitis

Laminitis is a disease that affects the feet of ungulates. It is best known in horses and cattle. Symptoms include lameness, and increased temperature in the hooves...

. Fresh grass is a particular danger to ponies; they can develop laminitis in as little as one hour of grazing on lush pasture.

Incorrect feeding is also as much a concern as simple overfeeding. Ponies and miniatures need a diet relatively low in sugars and starches and calories, but higher in fibers. Miniature horses in particular need fewer calories pound for pound than a regular horse, and are more prone to hyperlipemia than regular horses, and are also at higher risk of developing equine metabolic syndrome

Equine metabolic syndrome

Also known as Peripheral Cushings Disease and Equine Syndrome X.It is an illness affecting Equidae .This is an area of much new research and is increasingly believed to have a major role in conditions such as laminitis...

.

It is important to track the weight of a pony carefully, by use of a weight tape. Forages may be fed based on weight, at a rate of about 1 lb (0.45359237 kg) of forage for every 100 lb (45.4 kg). Forage, along with water and a salt and mineral block, is all most ponies require. If a hard-working pony needs concentrates, a ratio of no more than 30% concentrates to 70% forage is recommended. Concentrates designed for horses, with added vitamins and minerals, will often provide insufficient nutrients at the small serving sizes needed for ponies. Therefore, if a pony requires concentrates, feed and supplements designed specially for ponies should be used. In the UK, extruded pellets designed for ponies are sometimes called "pony nuts.".

Special feeding issues for mules and donkeys

Like ponies, mule

Mule

s and donkey

Donkey

The donkey or ass, Equus africanus asinus, is a domesticated member of the Equidae or horse family. The wild ancestor of the donkey is the African Wild Ass, E...

s are also very hardy and generally need less concentrated feed than horses. Mules need less protein than horses and do best on grass hay with a vitamin and mineral supplement. If mules are fed concentrates, they only need about half of what a horse requires. Like horses, mules require fresh, clean water, but are less likely to over-drink when hot.

Donkeys, like mules, need less protein and more fiber than horses. Although the donkey’s gastrointestinal tract has no marked differences in structure to that of the horse, donkeys are more efficient at digesting food and thrive on less forage than a similar sized pony. They only need to eat 1.5% of their body weight per day in dry matter. It is not fully understood why donkeys are such efficient digestors, but it is thought that they may have a different microbial population in the large intestine than do horses, or possibly an increased gut retention time.

Donkeys do best when allowed to consume small amounts of food over long periods, as is natural for them in an arid climate. They can meet their nutritional needs on 6 to 7 hours of grazing per day on average dryland pasture that is not stressed by drought. If they are worked long hours or do not have access to pasture, they require hay or a similar dried forage, with no more than a 1:4 ratio of legumes to grass. They also require salt and mineral supplements, and access to clean, fresh water. Like ponies and mules, in a lush climate, donkeys are prone to obesity and are at risk of laminitis.

Treats

Many people like to feed horses special treats such as carrot

Carrot

The carrot is a root vegetable, usually orange in colour, though purple, red, white, and yellow varieties exist. It has a crisp texture when fresh...

s, sugar cubes, peppermint candies, or specially manufactured horse "cookies." Horses do not need treats, and due to the risk of colic or choke, many horse owners do not allow their horses to be given treats. There are also behavioral issues that some horses may develop if given too many treats, particularly a tendency to bite if hand-fed, and for this reason many horse trainers and riding instructors discourage the practice.

However, if treats are allowed, carrots and compressed hay pellets are common, nutritious, and generally not harmful. Apples are also acceptable, though it is best if they are first cut into slices. Horse "cookies" are often specially manufactured out of ordinary grains and some added molasses. They generally will not cause nutritional problems when fed in small quantities. However, many types of human foods are potentially dangerous to a horse and should not be fed. This includes bread products, meat products, candy, and carbonated or alcoholic beverages.

It was once a common practice to give horses a weekly bran mash of wheat bran mixed with warm water and other ingredients. It is still done regularly in some places. While a warm, soft meal is a treat many horses enjoy, and was once considered helpful for its laxative effect, it is not nutritionally necessary. An old horse with poor teeth may benefit from food softened in water, a mash may help provide extra hydration

Tissue hydration

Tissue hydration is the process of absorbing and retaining water in biological tissues.-Plants:Land plants maintain adequate tissue hydration by means of an outer waterproof layer. In soft or green tissues, this is usually a waxy cuticle over the outer epidermis...

, and a warm meal may be comforting in cold weather, but horses have far more fiber in their regular diet than do humans, and so any assistance from bran is unnecessary. There is also a risk that too much wheat bran may provide excessive phosphorus, unbalancing the diet, and a feed of unusual contents fed only once a week could trigger a bout of colic.

Feed storage

All hay and concentrated feeds must be kept dry and free of mold

Mold

Molds are fungi that grow in the form of multicellular filaments called hyphae. Molds are not considered to be microbes but microscopic fungi that grow as single cells called yeasts...

, rodent

Rodent

Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....

feces, and other types of contamination that may cause illness in horses. Feed kept outside or otherwise exposed to moisture can develop mold quite quickly. Due to fire hazards, hay is often stored under an open shed or under a tarp, rather than inside a horse barn itself, but should be kept under some kind of cover. Concentrates take up less storage space, are less of a fire hazard, and are usually kept in a barn or enclosed shed. A secure door or latched gate between the animals and any feed storage area is critical. Horses accidentally getting into stored feed and eating too much at one time is a common but preventable way that horses develop colic or laminitis. (see Illnesses related to improper feeding below)

It is also important to never give a horse feed that was contaminated by the remains of a dead animal. This is a potential source of botulism

Botulism

. This is not an uncommon situation. For example, mice

Mouse

A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...

and bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s can get into poorly stored grain and be trapped; hay bales sometimes accidentally contain snake

Snake

Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...

s, mice, or other small animals that were caught in the baling

Hay

machinery during the harvesting process.

Feeding behavior

Horses can become anxious or stressed if there are long periods of time between meals. They also do best when they are fed on a regular schedule; they are creatures of habit and easily upset by changes in routine. When horses are in a herd, their behavior

Horse behavior

Horse behavior is best understood from the perspective that horses are prey animals with a well-developed fight-or-flight instinct. Their first response to a threat is to flee, although they are known to stand their ground and defend themselves or their offspring in cases where flight is...

is hierarchical; the higher-ranked animals in the herd eat and drink first. Low-status animals, who eat last, may not get enough food, and if there is little available feed, higher-ranking horses may keep lower-ranking ones from eating at all. Therefore, unless a herd is on pasture that meets the nutritional needs of all individuals, it is important to either feed horses separately, or spread feed out in separate areas to be sure all animals get roughly equal amounts of food to eat. In some situations where horses are kept together, they may still be placed into separate herds, depending on nutritional needs; overweight horses are kept separate from thin horses so that rations may be adjusted accordingly. Horses may also eat in undesirable ways, such as bolting

Bolting (horse)

Bolting when referring to equidae, generally refers to two different equine behaviors, both undesirable: the practice of running away without control, and the practice of eating food at a dangerously fast rate. However, there are other meanings as well...

their feed, or eating too fast. This can lead to either choke or colic under some circumstances.

Dental issues

Horses' teeth

Horse teeth

continually erupt throughout their life, are worn down as they eat, and can develop uneven wear patterns that can interfere with chewing. For this reason, horses need a dental examination

Horse care

There are many aspects to horse care. Horses, ponies, mules, donkeys and other domesticated equids require attention from humans for optimal health and long life.-Living environment:...

at least once a year, and particular care must be paid to the dental needs of older horses. The process of grinding off uneven wear patterns on a horse's teeth is called floating and can be performed by a veterinarian

Veterinarian

A veterinary physician, colloquially called a vet, shortened from veterinarian or veterinary surgeon , is a professional who treats disease, disorder and injury in animals....

or a specialist in equine dentistry.

Illnesses related to improper feeding

Colic, choke, and laminitis can be life-threatening when a horse is severely affected, and veterinary

Veterinarian

A veterinary physician, colloquially called a vet, shortened from veterinarian or veterinary surgeon , is a professional who treats disease, disorder and injury in animals....

care is necessary to properly treat these conditions. Other conditions, while not life-threatening, may have serious implications for the long-term health and soundness of a horse.

Colic

Horse colic

itself is not a disease, but rather a description of symptoms connected to abdominal pain. It can occur due to any number of digestive upsets, from mild bloating due to excess intestinal gas to life-threatening impactions. Colic is most often caused by a change in diet, either a planned change that takes place too quickly, or an accidental change, such as a horse getting out of its barn or paddock and ingesting unfamiliar plants. But colic has many other possible triggers including insufficient water, an irregular feeding schedule, stress, and illness. Because the horse cannot vomit and has a limited capacity to detoxify harmful substances, anything upsetting to the horse must travel all the way through the digestive system to be expelled.

Choke

Choke (horse)

is not as common as colic, but is nonetheless commonly considered a veterinary emergency. The most common cause of choke is horses not chewing their food thoroughly, usually because of eating their food too quickly, especially if they do not have sufficient access to water, but also sometimes due to dental problems that make chewing painful. It is exceedingly difficult for a horse to expel anything from the esophagus, and immediate treatment is often required. Unlike choking in humans, choke in horses does not cut off respiration.

Laminitis

Horses are also susceptible to laminitis

Laminitis

Laminitis is a disease that affects the feet of ungulates. It is best known in horses and cattle. Symptoms include lameness, and increased temperature in the hooves...

, a disease of the lamina of the hoof

Horse hoof

A horse hoof is a structure surrounding the distal phalanx of the 3rd digit of each of the four limbs of Equus species, which is covered by complex soft tissue and keratinised structures...

. Laminitis has many causes, but the most common is related to a sugar

Sugar

and starch overload from a horse overeating certain types of food, particularly too much pasture

Pasture

grass high in fructan

Fructan

A fructan is a polymer of fructose molecules. Fructans with a short chain length are known as fructooligosaccharides, whereas longer chain fructans are termed inulins...

in early spring and late fall, or by consuming excessive quantities of grain.

Growth disorders

Young horses that are overfed or are fed a diet with an improper calcium:phosphorus ratio over time may develop a number of growth and orthopedic disorders, including osteochondrosis

Osteochondrosis

Osteochondrosis is a family of orthopedic diseases of the joint that occur in children and adolescents and in rapidly growing animals, particularly pigs, horses, and dogs. They are characterized by interruption of the blood supply of a bone, in particular to the epiphysis, followed by localized...

(OCD), angular limb deformities (ALD), and several conditions grouped under the popular term "contracted tendons." If not properly treated, damage can be permanent. However, they can be treated if caught in time, given proper veterinary care, and any improper feeding practices are corrected. Young horses being fed for rapid growth in order to be shown or sold as yearling

Yearling (horse)

A yearling is a young horse of either sex that is between one and two years old. Yearlings are comparable in development to a very early adolescent, they are not fully mature physically, and while they may be in the earliest stages of sexual maturity, they are considered too young to be breeding...

s are at particularly high risk. Adult horses with an improper diet may also develop a range of metabolic problems.

Heaves

Moldy or dusty hay fed to horses is the most common cause of Recurrent airway obstruction

Recurrent Airway Obstruction

Recurrent airway obstruction, also known as broken wind, heaves, or sometimes by the term usually used for humans , is a respiratory disease in horses...

, also known as COPD or "heaves." This is a chronic

Chronic (medicine)

A chronic disease is a disease or other human health condition that is persistent or long-lasting in nature. The term chronic is usually applied when the course of the disease lasts for more than three months. Common chronic diseases include asthma, cancer, diabetes and HIV/AIDS.In medicine, the...

condition of horses involving an allergic bronchitis

Bronchitis

Acute bronchitis is an inflammation of the large bronchi in the lungs that is usually caused by viruses or bacteria and may last several days or weeks. Characteristic symptoms include cough, sputum production, and shortness of breath and wheezing related to the obstruction of the inflamed airways...

characterized by wheezing, coughing, and labored breathing.

"Tying up"

Equine Exertional Rhabdomyolysis

Equine exertional rhabdomyolysis is a syndrome that damages the muscle tissue in horses...

, also known as "tying up" or azoturia, is a condition to which only some horses are susceptible and most cases are linked to a genetic mutation. In horses prone to the condition, it usually occurs when a day of rest on full grain ration is followed by work the next day. This pattern of clinical signs led to the archaic

Archaism

In language, an archaism is the use of a form of speech or writing that is no longer current. This can either be done deliberately or as part of a specific jargon or formula...

nickname, "Monday morning sickness." The condition may also be related to elecrolyte imbalance. Proper diet management may help minimize the risk of an attack.

Footnotes and other references

"Horse Nutrition - Table of Contents." Bulletin 762-00, Ohio State University. Web site accessed February 9, 2007.
Mowrey, Robert A. "Horse Feeding Management - Nutrient Requirements for Horses." from North Carolina Cooperative Extension Center (PDF) Web site accessed July 4, 2009.

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

The digestive system

Chewing and swallowing

The stomach and small intestine

The cecum and large intestine

Nutrients

Water

Energy nutrients and protein

Vitamins and minerals

Types of feed

Forages

Concentrates

Grains

Mixes and Pellets

Supplements

Feeding practices

Feeding forages

Feeding concentrates

Access to water

Special feeding issues for Ponies

Special feeding issues for mules and donkeys

Treats

Feed storage

Feeding behavior

Dental issues

Illnesses related to improper feeding

Colic

Choke

Laminitis

Growth disorders

Heaves

"Tying up"

See also

Footnotes and other references