Talk:Equine nutrition

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	Equine nutrition has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do. If it no longer meets these criteria, you can delist it, or ask for a reassessment.
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[edit] Water

I thought I read somewhere that the "only give you horse a few sips of water after work" idea was a myth that was disproved. I'll try to find the source.Eventer 00:35, 12 February 2007 (UTC)

Me too, but I can't source it, and the Extension service articles I used, particularly the Ohio State stuff, mention the slow cool down, so absent a more recent study, best to be cautious. I actually thought they did well to say that a horse can drink its fill WHILE WORKING, but not after...so that alone is a little more modern approach. And I think that some of the water thing may have to do with HUMAN exercise physiology...beats me. If you find something sufficiently scientific to be a reliable source, go for it, maybe in the form of, "it used to be this way, but new studies suggest it can be that way..." Montanabw 16:59, 12 February 2007 (UTC)

[edit] Tying up

Can we source "Failure to do so could lead to Equine Exertional Rhabdomyolysis, or "tying up," a very serious muscular problem." I am running across stuff in some magazines that suggests that tying up is genetically triggered...? Montanabw 17:41, 12 February 2007 (UTC)

OK, did a bit of research. According to the Illustrated Atlas of Clinical Equine Anatomy and Common Disorders of the Horse (I will source when I have the time. Its a great reference, btw), the "pathogenesis of ER is not clearly understood". Possbile causes include: 1) change of blood supply in muscle 2) electrolyte or fluid imbalance 3) genetic predisposition 4) nutritional influence. For the electrolyte imbalance: diets usually consist of hay and cereal grains, which generally consist of high levels of K+ and low levels of Na+ ions. These ions are especially important to the muscle and nerve tissue, thus incorrect levels are a possible cause of ER. Fillies and mares are apparently more prone to getting ER, especially those that are "highly anxious," suggesting an endocrine influence. Also certain family lines seem to be more prone (genetics). Eventer 02:24, 15 February 2007 (UTC)

If you can come up with a really short little paragraph with the bibliographical source, go for it! Montanabw 23:34, 15 February 2007 (UTC)

[edit] Copyright problem--moving to subpage

Noting that I have moved previous text to Talk:Equine nutrition/Temp. Will work on sourcing. This was overkill as I did not copy the article from Rutgers, though it was a major source. Montanabw 19:24, 14 February 2007 (UTC) —The preceding unsigned comment was added by Montanabw (talk • contribs) 17:25, 14 February 2007 (UTC).

Further note: Article has been footnoted and restored by another admin. Would suggest to overeager admins in the future to please warn and provide 24 hours to fix rather than an immediate lockdown. Montanabw 01:44, 15 February 2007 (UTC)

[edit] Sandbox for Digestive system rewrite

Section needs rewrite, combine with horse anatomy, sourcing, etc. Working on it here

[edit] From Owners Veterinary Handbook -- do not edit within this section, cut and paste from here

<ref name=”Vet handbook”>Giffen, James M. and Tom Gore. ‘’Horse Owner’s Veterinary Handbook., 2nd ed. New York:Howell Book House, 1989, 1998. ISBN 0876056060</ref>

Horses do not have a gall bladder to store bile.

Oral cavity: lips, cheeks, hard and soft palate, tongue and muscles. four pairs of salivary glands. Prehensile lips, sharp incisors for cutting, molars, or cheek teeth grind plant matter.

Esophagus is 5 feet long, enters the stomach at an acute angle, creating a one-way valve, which is why horses cannot vomit. Powerful spincter mechanism at the gastroesophageal junction, vomiting and reflux uncommon

Stomach can hold 4 gallons, most efficient when filled to 2 gallons. Acid and pepsin. Pepsin breaks down proteins into amino acids

Stomach empties when 2/3 full, whether stomach enzymes have completed their processing of the food or not, can prevent full digestion and proper utilization of feed. this is why several small feedings are preferable to a few large ones.

Pancreas produces digestive enzymes and insulin.

Small intestine is 70 feet long, holds 12 gallons, three parts are the duedenum, jejunum and ileum. Bile from the liver acts here, combined with enzymes from the pancreas and enzymes from the small intestine.

Most food is digested and absorbed into the bloodstream from the small intestine. Liquids and roughage move into the large intestine.

Large intestine is 25 feet long total, and consists of the cecum, large colon, small colon and rectum. Large colon is the most frequent site of impactions.

Cecum is 4 feet long, holds 7 to 10 gallons. Contains bacteria that feeds upon digestive chyme, and breaks down cellulose by means of fermentation. Bacteria in the cecum also produce certain fat-soluble vitamins, absorbed by the horse.

Large colon is 10-12 feet long, holds 20 gallons of semi-liquid matter. Small colon is also 10-12 feet long, but smaller diameter. It absorbs water and forms waste products. The rectum is one foot long and holds waste material until is is passed from the horse’s body.

Most common cause of choke is horses not chewing their food thoroughly, usually because of eating their food too quickly, but also sometimes due to dental problems that make chewing painful. Choke does not cut off respiration.

Colic itself is not a disease, but rather a description of symptoms connected to abdominal pain.

[edit] The digestive system-- new

Main article: Horse anatomy

Horses and other Equids evolved as grazing animals, adapted to eating small amounts of the same kind of food all day long. In the wild, the horse adapted to eating prairie grasses in semi-arid regions and traveling significant distances each day in order to obtain adequate nutrition.^[1]

[edit] The mouth

Digestion begins in the mouth, which is also called the "oral cavity." Horses select pieces of forage and pick up finer foods, such as grain, with their sensitive, prehensile, lips.The front teeth of the horse, called incisors, clip forage, and food is then pushed back in the mouth by the tongue, and ground up for swallowing by the premolars and molars. ^[2]

[edit] The esophagus

The esophagus is about 5 feet in length, and carries food to the stomach. The esophagus enters the stomach at an acute angle, creating a one-way valve, with a powerful spincter mechanism at the gastroesophageal junction, which is why horses cannot vomit.^[2] The esophagus is also the area of the digestive tract where horses may suffer from choke. (see also: choke (horse))

[edit] The stomach

Horses have a relatively small stomach for their size, and this limits the amount of feed a horse can take in at one time. The average sized horse (800 to 1200 lbs) has a stomach with a capacity of only four gallons, and works best when it contains about two gallons. Because the stomach empties when 2/3 full, whether stomach enzymes have completed their processing of the food or not, which prevents full digestion and proper utilization of feed, continuous foraging or several small feedings per day are preferable to one or two large ones.^[2]

In the stomach, assorted acids and the enzyme pepsin break down food. Pepsin allows for the further breakdown of proteins into amino acid chains.^[2] Other enzymes include resin and lipase. Additionally, the stomach absorbs some water, as well as ions and lipid soluble compounds. The the end product is food broken down into chyme.^{[citation needed]} It then leaves the stomach through the pyloric valve, which controls the flow of food out of stomach.^{[citation needed]}

[edit] The small intestine

The horse’s small intestine is 50 to 70 feet long and holds 10 to 12 gallons. This is the major digestive organ, and where most nutrients are absorbed.^[3] It has three parts, the duedenum, jejunum and ileum. Bile from the liver acts here, combined with enzymes from the pancreas and small intestine itself. Horses do not have a gall bladder, so bile flows constantly. Most food is digested and absorbed into the bloodstream from the small intestine. Any remaining liquids and roughage move into the large intestine.^[2]

[edit] The cecum and large intestine

The cecum is the first section of the large intestine. the cecum is also known as the "water gut" or "hind gut." It is a cul-de-sac pouch,^[3] about 4 feet long that holds 7 to 8 gallons. It contains bacteria and protozoa that digest cellulose plant fiber through fermentation, and any soluble carbohydrates.^[4] These bacteria feed upon digestive chyme, and also produce certain fat-soluble vitamins which are absorbed by the horse.^[2] The reason horses must have their diets changed slowly is so the bacteria in the cecum are able to modify and adapt to the different chemical structure of new feedstuffs.^[3] Too abrupt a change in diet can cause colic, as the new food is not properly digested.

The large colon, small colon, and rectum make up the remainder of the large intestine. The large colon is 10-12 feet long and holds up to 20 gallons of semi-liquid matter. It is made up of the right lower (ventral) colon, the left lower (ventral) colon, the left upper (dorsal) colon, the right upper (dorsal) colon, and the transverse colon.^[2] Its main purpose it 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 called an impaction.^[4][3]

The small colon leads is 10-12 feet in length and holds only 5 gallons of material. It is the area where the majority of water in the horse's diet is absorbed, and is also the place where fecal balls are formed. The rectum is about one foot long, and acts as a holding chamber for fecal matter, which is then expelled from the body via the anus.^[2]

[edit] From Equine nutrition-- OLD

[edit] The digestive system

Main article: Horse anatomy

Horses and other Equids evolved as grazing animals, adapted to eating small amounts of the same kind of food all day long. In the wild, the horse adapted to eating prairie grasses in semi-arid regions and traveling significant distances each day in order to obtain adequate nutrition.^[5]

[edit] The mouth

Digestion begins in the mouth, also called the "oral cavity." The front teeth of the horse, called incisors, clip forage, and horses pick up finer foods, such as grain, with their lips. Food is then pushed back in the mouth by the tongue, and ground up for swallowing by the premolars and molars. ^{[citation needed]}

When swallowing occurs, the soft palate (a flap of tissue in the back of the mouth) closes over the pharynx of the animal, which prevents food from going down the trachea, but momentarily prevents the horse from being able to breathe. This soft palate is also the reason why horses cannot breathe through their mouth when they are in respiratory distress.^{[citation needed]}

[edit] The esophagus

The esophagus is about 4-5 feet in length, and carries food to the stomach. Due to the coronary sphincter, the esophagus only allows the passage of food in one direction, and this is why horses cannot vomit. It is also the area of the digestive tract where horses get choke, or esophageal obstruction, due to eating something that is too large or dry to pass down the length of the esophagus. Therefore, unlike humans, equine choke does not prevent the animal from breathing, but is still a very serious problem that can eventually lead to pneumonia if left untreated.^{[citation needed]}

[edit] The stomach

Horses have a relatively small stomach for their size that limits the amount of feed a horse can take in at one time. The average sized horse (800 to 1200 lbs) has a stomach with a capacity of only 2 to 4 gallons,^[4] and works best when it is about 2/3 full.^{[citation needed]} Therefore, best management allows horses to have continuous access to forage or at least several small meals, as opposed to one or two large meals a day.^{[citation needed]}

Food arrives into the stomach from the esophagus. The majority of gastric juice is made up of hydrochloric acid, which turns pepsinogen into the enzyme pepsin. Pepsin allows for the partial breakdown of proteins. Other enzymes include resin and lipase. Additionally, the stomach absorbs some water, as well as ions and lipid soluble compounds. The main purpose of the stomach, however, is to break down food into chyme.^{[citation needed]} It then leaves the stomach through the pyloric valve, which controls the flow of food out of stomach.^{[citation needed]}

[edit] The small intestine

The horse’s small intestine is 50 to 70 feet long and holds 10 to 23 gallons. This is the major digestive organ, and where most nutrients are absorbed.^[3]

Additionally, the pancreas and liver both play a role in the small intestine, by secreting a very alkaline digestive juice about 5-6 inches from the pyloric valve. This counteracts the acidity of the chyme arriving from the stomach and prevents it from eating through the tissue of the intestine.^{[citation needed]}

[edit] The cecum and large intestine

Most liquids are passed to the cecum, also known as the "water gut" or "hind gut." It is a cul-de-sac pouch,^[3] about 3 to 4 feet long that holds 7 to 8 gallons. It contains bacteria and protozoa that digest plant fiber (through fermentation) and any soluble carbohydrates.^[4] Horses must have their diets changed slowly so that the bacteria in the cecum are able to modify and adapt to the different chemical structure of new feedstuffs.^[3] Too abrupt a change in diet can cause colic, as the new food is not properly digested.

The large colon, small colon, and rectum make up the large intestine. The large colon is about 12 feet long and holds up to 20 gallons. Its main purpose it 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 called an impaction.^[4][3]

The small colon leads is 10-12 feet in length and holds only 5 gallons of material. It is the area where the majority of water in the horse's diet is absorbed, and is also the place where fecal balls are formed.^{[citation needed]}

The rectum is about one foot long, and acts as a holding chamber for fecal matter, which is passed out the anus.^{[citation needed]}

[edit] From Horse anatomy-- OLD

The equine digestive system is about 100 feet in length. Fermentation of cellulose occurs in the cecum (hind-gut), unlike the four-chambered stomachs of ruminants. The equine gastro-intestinal tract is prone to complications (such as colic) that can easily become fatal. Consists of:

1. Oral cavity: where the lips, teeth, and tongue work to grind food up for swallowing
2. Esophagus: the tube that carries the food to the stomach
3. Stomach: A holding tank for food, that also begins to absorb nutritional elements, and breaks down food into much smaller material. The horse stomach consists of a non-glandular blind sac (saccus cecus), divided by a distinct border, the margo plicata, from the glandular stomach.
4. Small intestine: Consists of the duodenum, jejunum, and ileum. Site of digestion of proteins, simple carbohydrates, and fats.
5. Cecum: Extremely large in the horse, responsible for fermentation of cellulose (equivalent function to the rumen in cattle). Consists of a base, body, and apex.
6. Large intestine (colon): The large (ascending) colon consists of the right ventral colon, sternal flexure, left ventral colon, pelvic flexure, left dorsal colon, diaphragmatic flexure, right dorsal colon, and joins with the small (descending) colon. Absorbs water and nutrients.
7. Rectum: forms manure balls and is the holding area for feces

[edit] References

1. ^ Budiansky, Stephen. The Nature of Horses. Free Press, 1997. ISBN 0-684-82768-9
2. ^ ^{a b c d e f g h} Giffen, James M. and Tom Gore. ‘’Horse Owner’s Veterinary Handbook., 2nd ed. New York:Howell Book House, 1989, 1998. ISBN 0876056060
3. ^ ^{a b c d e f g h} "Horse Nutrition - The Horse's Digestive System." Bulletin 762-00, Ohio State University. Web site accessed February 9, 2007.
4. ^ ^{a b c d e} Williams, Carey A.,Ph.D., Extension Specialist. "The Basics of Equine Nutrition" from FS #038, Equine Science Center, Rutgers University, Revised: April 2004. Web site accessed February 9, 2007
5. ^ Budiansky, Stephen. The Nature of Horses. Free Press, 1997. ISBN 0-684-82768-9

[edit] Good article passed

Two things should be improved though:

1. The section titled 'how to feed' needs to be renamed to 'amount and composition of feed' or something like that. Wikipedia is not a how-to-guide. I passed it nevertheless because it is only the wording of the headline, the content is worded in an encyclopedic tone.
2. The writing is not brilliant yet. There are many repetitions: 'horses do graze a lot' is mentioned at least four times throughout the article, sometimes it is necessary for content, sometimes it isn't. At least the caption of the first image needs to be changed, because the fact that horses are grazing is mentioned at least three times during the first screenfull of text. Similarly, replace the repeatedly used word 'horses' by equids or some other noun in a third of the cases.

• Other than that: nice work, good article.--DorisH 16:31, 20 March 2007 (UTC)

[edit] Silage statement

I question this line "they must never be fed fermentable materials such as silage" .. This was the opinion for a long time, but has changed drastically over the past 10 - 15 years. The mold issue in silage is a lesser issue because it is highly visible, and thus can be discarded and not fed to horses - where as mold in hay can go undiscovered under a longer period of time. I know several serious stables that feed a mix of hay and silage to all their horses. Thoughts? mceder (u t c) 20:32, 1 May 2007 (UTC)

Mold that you can see obviously isn't good, it causes respiratory problems, etc., but it's not usually fatal. You can't see botulism spores and other toxins. Botulism can be in both silage and in the big round bales and is an issue. But, like round bales, people do feed silage. But both have some risks. Fermentation in general is not good for horses, either, they lack the multi-chambered stomach to detoxify it (part of why grass clippings are so bad, they ferment and form toxins long before you see visible mold).

Oh, and if you have a source from a University research on silage and spoilage that supports your views, please present it. In the meantime, the silage issue is referenced to University Extension materials which recommend against it. If this research has been superseded, it will be useful to know. Montanabw 21:22, 1 May 2007 (UTC)

Yeah I have been looking for some English version of what I have found. It appears most research is from Scandinavia, where ensilage feed to horses is common. Will bring it here if I find something. mceder (u t c) 06:56, 17 May 2007 (UTC)

The "haylage" stuff in the UK -- the bagged fresh grass, or whatever it is -- sort of raises some of the same botulism and mold toxin concerns. Maybe there is a process of some sort that they use that makes it safe, I don't know. Be interesting to find out. 161.7.2.160 19:21, 17 May 2007 (UTC)