Horse Feeding Myths and Misconceptions

Compared to other classes of livestock, there seems to be more myths and wives' tales when it comes to feeding horses. Many of these myths are long-held "traditions" that have been passed down unquestioned from horseman to horseman. Some myths are based on fear of causing harm to the horse. Other myths stem from lack of understanding of either the feed or how the horse may digest it.

Over the past 30 years, many of the myths and wives' tales associated with the feeding of horses have been debunked through scientific study. So, why are these feeding rumours still circulating? Most likely the wives' tales persist because it is difficult to change tradition—"It has always been done that way." In addition, maybe we haven't been good enough at getting the word out there that certain feeding practices are unfounded. Therefore, the purpose of this paper is to set the record straight!


Myth: "Bran Mashes Have a Laxative Effect."

One of the oldest management practices associated with horses is the weekly feeding of a hot bran mash. While there are numerous recipes for these concoctions, the main ingredient is wheat bran. When horses were used for farm work, this mash was usually offered on Saturday night, the eve of their one day of rest. Mashes were thought to have a laxative effect that would "clean them out" and help to prevent colic. Although most horses aren't used for farm work today, many still receive this weekly bran mash for the same reasons.

Research has shown that bran does not have a laxative effect. Studies have found that adding wheat bran to the diet did not soften the stools. In fact, the moisture content of the manure was similar whether the horses received wheat bran or not. Instead, wheat bran increases the bulk of the manure, giving the appearance that the horse is dumping a bigger pile.

Many attributed the "laxative" effect to the fibre in wheat bran. Physicians recommend their patients eat bran cereal or a bran muffin to stay "regular," so wheat bran should work the same for horses, shouldn't it? In truth, wheat bran is not a high fibre feed. Sure, wheat bran has more fibre than corn, but it has about the same amount of fibre as oats (Table 1). And wheat bran definitely has less fibre than hay (Table 1). So, why does bran work as a laxative for humans and not horses? To understand, you must consider that the typical equine diet contains more than 35% fibre (over 3,500 g), whereas the typical human diet contains less than 2% fibre (25 to 30 g). So, a scoop of wheat bran will hardly make a dent in the high-fibre diet of the horse, but a bran muffin will probably contribute a significant amount of fibre to the low-fibre diet of a human.

Although wheat bran is not a laxative, it can be quite tasty and provide energy and protein at levels similar to oats (Table 1). For these reasons, wheat bran should be thought of as grain, rather than forage. However, all brans, including wheat and rice bran, are very high in phosphorus (Table 1). About 90% of the phosphorus in brans in the form of phytate, which decreases calcium absorption, as well as reduces the absorption of copper, zinc and manganese. If you feed a couple of pounds of bran (wheat or rice) every day, the diet must be balanced with adequate calcium.

Those of you who feed a bran mash once a week may be off the hook for causing mineral imbalances, but you may instead be upsetting the microorganisms in the digestive tract. Most horsemen heed the warning that any changes to the diet should be made gradually to avoid colic. Yet these same horsemen don't see a problem with providing a bran mash once a week. Despite the good intentions, a weekly bran mash is a dramatic feed change and will upset the delicate balance of microorganisms that aid in digestion of the normal hay and grain. Killing the good bacteria in the gut usually results in diarrhea, which could be another reason why horsemen over the years believed wheat bran acted as a laxative.

Should bran mashes be avoided altogether? No, but you may need to rethink why and how often you are feeding them. If you want a laxative, wheat bran is not going to work. If it gives you a warm-fuzzy feeling to prepare a treat for your horse, go with a bran mash. However, feed it every day to avoid upsetting the digestive tract. And if you are feeding more than a pound of bran per day, make sure you are also balancing the mineral content of the diet to offset the high phosphorus content of the bran (either with a mineral supplement or a feed naturally high in calcium, like alfalfa hay or beet pulp).


Table 1: Comparison of the nutrients in wheat bran and rice bran to other common feeds.*

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* Please note these are average nutrient values and are presented on a 100% dry matter basis.


Myth: "You Should Never Give a Horse Straight Alfalfa."

For horse owners, alfalfa is probably the most misunderstood feed. Perhaps this explains why there are so many wives' tales surrounding the feeding of alfalfa to horses. I'll attempt to diffuse a few of the more common myths about alfalfa below.


Myth: "You should never give a horse straight alfalfa."
Never say never. In California and the southwest United States, horses are routinely fed straight alfalfa as the only forage. In that region, alfalfa is cheap, plentiful, and the horses do quite well. While some horses may not need alfalfa, others would truly benefit from receiving alfalfa. The difference lies in what nutrients alfalfa provides, and what the horse actually needs. Alfalfa contains more energy, protein and calcium than most grass hays, such as timothy, brome grass, orchard grass, etc (Table 2). This nutrient profile makes it most suitable for young, growing horses and lactating mares, because they have high protein and mineral requirements (Table 3). By comparison, alfalfa exceeds the protein requirements of idle horses and performance horses (Table 3). That does not mean these horses cannot receive straight alfalfa. It just means alfalfa provides more protein than these classes of horses need. Alfalfa also tastes good, so it's useful when you've got a finicky eater or a horse with a poor appetite.

While alfalfa is more nutrient-rich than most other forages, it is not any richer than many other feeds commonly used for horses. For example, good quality pasture is often higher in calories and protein than alfalfa hay (Table 2). Leafy, rapidly growing spring pasture grass may contain 20 to 26% protein. By comparison, mid-maturity alfalfa hay will contain 16 to 18% protein.


Table 2: Comparison of the nutrients in alfalfa with other forages.*

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* Please note these requirements are presented on a 100% dry matter basis.


Myth: "Straight alfalfa should not be fed to young, growing horses."
Foals do not have the same capacity as an adult horse to house and digest lots of mature forage in an effort to obtain the nutrition they need for growth. Foals have greater nutrient needs than adult horses, but a digestive system only one-third as big. As a result, growing horses need a nutrient-dense diet-lots of nutrition in a small package. Alfalfa can help us meet their high energy, protein and calcium needs without having to add a lot of extra bulk to the diet (Table 3). High protein does not cause developmental orthopaedic disease (more on that later), nor does high calcium. Furthermore, we can adjust the high calcium to phosphorus ratio in alfalfa with a suitable mineral supplement.


Myth: "Straight alfalfa causes colic and founder."
Very few people who circulate this myth have ever actually experienced these problems themselves. And since most people don't want to risk their horse developing colic or laminitis, this rumour stuck. I'm not saying it couldn't happen (never say never). Some horses may be predisposed to colic and founder, particularly obese horses and fat ponies. For these easy keepers, alfalfa may be too much of a good thing and is probably better avoided. However, most feed-related cases of colic or laminitis tend to result from feeding grain, alfalfa or other feeds incorrectly.

Because it is richer in energy and protein, alfalfa should be limit-fed—fed in a fixed amount—rather than offered free-choice. Horses that are fed too much alfalfa or allowed to eat as much as they want often relish the forage so much they will become obese. And obesity is certainly a predisposing factor for colic and laminitis. Because alfalfa has a higher nutrient value, less alfalfa hay will be needed to meet the horse's requirements, compared to the amount of grass hay needed. For example, a mature, 1100-lb horse used for light work will only need 16 lbs of alfalfa each day, but would need 22 lbs of timothy hay to meet dietary requirements.

Risk of colic or laminitis also increases when people switch from a mature grass hay to a good alfalfa hay without giving the horse time to adjust to the diet change. The microorganisms in the horse's digestive tract need time to adjust to new feeds, particularly when going from a low quality feed to a higher quality feed. So, if you are switching to a straight alfalfa hay, adjust the horse to alfalfa gradually over a period of 1 to 2 weeks (each day or two, replace more of the old hay with the alfalfa). And remember you will be feeding a fixed amount of alfalfa, probably less hay than you were feeding before.

The same is true for grazing a horse on an alfalfa pasture. Horses can safely graze on an alfalfa stand if given time to adjust to the forage. Start with 2 to 4 hours of grazing and gradually build up the turnout time over 1 to 2 weeks. Keep in mind that mature horses may not need to graze 24 hours per day to obtain all the nutrients they need if the pasture is of high quality. To make better use of your pasture and to avoid obesity, consider restricting grazing time.


Myth: "Alfalfa causes bloat in horses."
Alfalfa (or any legume) can cause bloat in cattle and other ruminants, and presumably that's where this myth began. As cattle digest forages, the microorganisms in their rumen naturally produce gas. In most cases, cattle eliminate this gas by burping up cud for re-chewing (the process of rumination). When cattle graze lush pastures full of clover and alfalfa, a froth develops, trapping the gas in the rumen, thereby leading to a bloated appearance. In contrast, horses do not develop bloat when grazing alfalfa because of the layout of their digestive tract. The alfalfa must first pass through the horse's stomach and small intestine before it undergoes microbial digestion in the large intestine. Because significant digestion of alfalfa takes place in the stomach and small intestine, there is less of a chance for gas to become trapped in the large intestine and cause bloat. As mentioned above, gradually adapting horses to pastures with alfalfa will help prevent many problems.


Myth: "Alfalfa causes kidney damage."
Although alfalfa may provide more protein than mature horses need, there is no evidence to suggest that a moderate dietary excess of protein is detrimental to healthy horses. Protein is made up of amino acids, which are composed of carbon, hydrogen, oxygen and nitrogen. When horses (or humans) consume more protein than they need, the carbon, hydrogen and oxygen from the amino acids are used for energy and the excess nitrogen is excreted in the urine. Horses consuming alfalfa (and other high protein feeds) have been noted to drink more often and urinate more than horses consuming lower protein diets. But there is no reason to believe that a horse's kidneys will be damaged when this occurs. It's only when a horse already has pre-existing kidney disease that the high calcium and protein in alfalfa can aggravate kidney dysfunction.

When feeding alfalfa, it is important to provide free-choice access to water to ensure the horse can flush the excess nitrogen from its body. When alfalfa-fed horses receive only restricted access or limited amounts of water, they often produce more concentrated brown, thick urine.


Myth: "Beet Pulp is Just A Filler."

Most old-timers will tell you beet pulp has no nutrition, "it's just a filler." Again, science has proved otherwise. Beet pulp is the fibrous material left over after the sugar is extracted from sugar beets. It's an excellent source of digestible fibre for the horse and can be fed in addition to, or instead of, hay. Recent research has shown that the fibre in beet pulp is easier to digest than the fibre in hays. In fact, horses may derive as much energy from beet pulp as they do from oats (Table 4). In other words, a pound of (dry) beet pulp has almost the same amount of calories as a pound of oats. Because beet pulp provides these calories as fibre (as opposed to the starch in grains), it can be safely fed in larger amounts without the risk of colic or laminitis associated with feeding a large amount of grain. Furthermore, the protein content of beet pulp (averaging 8 to 12%) is comparable to most grains and good-quality grass hays (Table 4). And, beet pulp also provides a reasonable source of calcium, intermediate between the high calcium in alfalfa and the lower calcium content of grass hays, but much higher than grains (Table 4).

Whether used as a source of forage or as a replacement for oats, beet pulp is a useful addition to the diet of many types of horses. Beet pulp has been successfully fed at levels up to 50% of the horse's total ration (approximately 10 lbs for a 1000 lb horse). More commonly, owners choose to feed 2 to 5 lbs of beet pulp per day. The high digestibility of beet pulp makes it a good choice for horses that are "hard keepers" (it's very good for encouraging weight gain), as well as horses with dental problems, or older horses who have trouble chewing or digesting other types of forage. Beet pulp is also used as a grain replacement in the diets of horses that suffer from tying up (providing calories as fibre rather than starch). And the low potassium content of beet pulp makes it an ideal forage replacement for horses with HYPP. Finally, endurance riders favour beet pulp because its high water holding capacity provides the horse with a larger reservoir of fluid in the digestive tract that can be used to help prevent dehydration.


Table 4: Comparison of the nutrients in beet pulp with the nutrients in other common feeds.*

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* Please note these are average nutrient values and are presented on a 100% dry matter basis.


Myth: "Beet Pulp Must be Soaked Before You Feed It."

"If you don't soak beet pulp before feeding it, it'll swell up and rupture the horse's stomach." "Beet pulp will swell up in your horse's esophagus and cause choke if you don't soak it first." These are just a couple of the diabolical warnings surrounding the feeding of beet pulp. Because beet pulp seems to "grow" when water is added, somebody surmised that it could be a hazard if fed dry because it would absorb saliva and gastric juices, swell up, and block the esophagus or cause the stomach to burst. Although inaccurate, these evil predictions deter many horse owners from even trying beet pulp.

Beet pulp may soak up water like a sponge, but it cannot soak up saliva quickly enough to expand in the esophagus and cause choke. Instead, choke associated with beet pulp (particularly the pelleted form) is often in response to the particle size and the horse's aggressive feeding behaviour, rather than the actual feed itself. Horses that bolt their feed without sufficient chewing, or do not have adequate access to water, are far more likely to choke, regardless of the type of feed, compared to horses that eat at a more leisurely rate.

Nor is it likely that dry beet pulp will rupture the horse's stomach. The equine stomach holds 2 to 4 gallons. This volume is equivalent to 4.5 to 9.5 pounds of dry beet pulp, which is more than most horses receive in a single meal. Likewise, most food that enters the stomach passes on to the small intestine within 15 minutes or less—and for those of you who have timed how long it takes beet pulp to expand, it's longer than 15 minutes. Assuming free access to water, horses will voluntarily drink enough water to adequately process any amount of beet pulp consumed (1.5 to 2 litres per pound of beet pulp). Along with this drinking water, fluid is constantly entering the digestive tract, so beet pulp will not "suck the horse dry." Ultimately, the 40 to 50 gallon capacity of the equine digestive tract is more than sufficient to contain even a very large meal of beet pulp. The only horse in danger of a gastric rupture is one suffering from impaction or other severe lack of normal peristaltic movement.

So, contrary to popular belief, you don't have to soak beet pulp (either the pelleted or shredded form) in water to feed it safely to horses. Research at several universities, including some of my own studies, have fed dry beet pulp in amounts up to 50% of the total diet without choke or other adverse reactions. Likewise, many, many tons of dry beet pulp-based feeds are fed annually without incidence. For example, most commercial feeds designed for geriatric horses contain large amounts of beet pulp and are fed straight out of the bag without being soaked first. If you choose not to soak the beet pulp before feeding it, make sure your horse has access to as much good, clean water as he wants (which should be the case no matter what you feed).

Although soaking beet pulp is not necessary, there are several good reasons for wetting it down before you feed it. Soaking beet pulp may make the feed easier to chew, particularly for older horses with bad teeth. Soaked beet pulp may also be more tasty and it provides a useful method for hiding minerals or medications. If your horse gobbles down his feed or is prone to choke, it might be a good idea to soak your beet pulp. And while horses will drink water on their own, pre-soaked beet pulp is a good way to get some water into your horses, particularly in the winter when they may not be as inclined to drink what they need. So, if soaking beet pulp fits into your feeding management, by all means, do it. You don't have to soak beet pulp overnight-most of the expansion takes place within the first 3 to 4 hours.


Myth: "High Protein Feeds Make My Horse Too High Spirited."

The belief that behaviour can be affected by feeding hays or grain mixes with a high protein content is probably one of the most common misconceptions among horsemen. There is no data, either scientific or otherwise, which suggests that protein intake has anything to do with mental attitude. However, high-spirited behaviour has been directly linked to the energy content of the diet. The horse is unique in that it compensates for excess dietary energy by increasing physical activity. As a result, the horse that receives too much energy (calories) in the diet is more apt to be excessively high spirited and buck, shy or run away.

To gain a better understanding, the horse owner must be able to differentiate between the energy and the protein content of the diet. High protein does not necessarily mean high energy, and vice versa. Grains have 30 to 50% more energy than hays, but not necessarily more protein (Table 5). Overactive behaviour might result if the horse is receiving more grain than is needed, or if you have switched to another type of grain than contains more energy. For example, on a pound-for-pound basis, corn and wheat contain 10% more digestible energy than oats, but they aren't necessarily higher in protein (Table 5). Furthermore, corn and wheat are more energy-dense (heavier bushel weight), so these grains provide twice as much energy as an equal volume of oats. If you were feeding a coffee can of oats and you switched to corn, you would only need to feed half a can to provide the same amount of calories. If you stayed with a whole can of corn, you would be providing your horse twice as much energy. The same is true for some grain mixes—some sweet feeds and pellets may contain a higher proportion of corn, wheat or barley, and some contain added fats or oils, all of which have more energy per pound than oats.

Beyond the grain source, too much energy can also come from the hay. Alfalfa, although high in protein, is also higher in energy than most grass hays like timothy (Table 5). If the amount of alfalfa fed supplies more calories than the horse needs, it is the energy content of the alfalfa, not the protein content, causing his hyper behaviour.

The bottom line: too much energy in the diet (excess calories) = too much energy in the horse (hyper behaviour). Protein level has nothing to do with it. And remember that horses are individuals. Some horses are more high-strung than others and will feel the need to burn off excess dietary energy, particularly if they are confined to a stall for most of the day. Other horses demonstrate the opposite effect with excess calories—they become fat and lazy. And keep in mind that the diet may not be to blame. Maybe the horse needs additional training to become more manageable, or perhaps they are experiencing some type of pain or discomfort.


Table 5: Comparison of the energy and protein content of common grains and hays fed to horses.*

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* Please note these are average nutrient values and are presented on a 100% dry matter basis.


Myth: "Performance Horses Need a High Protein Diet."

Several surveys conducted on feeding practices have revealed that mature performance horses receive two to three times as much protein in their diet as they require. The common belief that once a horse enters training, or is ridden or shown extensively, the activity substantially increases the need for more protein in the diet is false.

This myth likely has its roots in human nutrition. For hundreds of years, it was believed that exercise and training involved the "tearing down of old muscle, and the building of new muscle." Since muscle is primarily composed of protein, it was deduced that more protein was needed in the diet of human athletes to serve as the building blocks for new muscle. A significant amount of both human and equine research over the last 50 years has disproved this theory. But both human athletes (the prime example being body builders) and horse owners have been slow to catch on.

I do not deny that protein needs increase with training and exercise, because they do (Table 6). However, protein needs do not increase greatly with exercise, particularly when you compare the protein needs of a working horse to a young, growing horse, or a broodmare (Table 6).

The nutrient affected most when a horse enters training or is being ridden consistently is energy, the calorie content of the diet. When a horse (or human) is exercising, the muscles doing the work are burning lots of calories. So, it should make sense that we need to provide more calories in the diet of a working horse to compensate for all the extra calories he expends when being ridden or worked. As the level of activity increases (either by speed or distance), the requirements for energy increase proportionally (Table 6). For light riding a few times a week, the horse's energy requirements increase approximately 25% over that needed by an idle horse. For moderate work, such as barrel racing, jumping, team penning, cutting, etc., energy requirements may increase by 50%. For intense work, such as racing and endurance riding, energy requirements can increase by more than 100% over the idle horse.

Therefore, while protein needs do increase slightly with exercise (2 - 3%), energy needs increase dramatically (25 - 100%). In most cases, we can meet the increased protein needs of performance horses when we adjust the diet to provide for the increased energy needs.


Table 6: Comparison of energy and protein requirements for different classes of horses with a mature weight of 1100 lbs (500 kg).*

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* Please note these requirements are presented on a 100% dry matter basis.


Myth: "High Protein Diets Cause Development Problems in Foals."

Genetics, exercise and nutrition all play a role in the development of healthy bones, and as a result, the same factors are also linked to the occurrence of developmental orthopedic disease (DOD) in young horses. Most confusion regarding DOD is related to nutrition. Mineral imbalances have been well-documented as a cause of DOD. Excessive protein was blamed as a cause in the 1970's, but later studies disproved this connection. Feeding more protein than the foal needs does not increase growth rate above that achieved when the diet just meets protein requirements. Unfortunately, the diets of many young horses are kept quite low in protein for fear of causing developmental problems. Restricting protein will not result in improved bone growth, and can actually be harmful to the foal by decreasing feed intake, growth rate and skeletal development. On the other hand, overfeeding energy will result in developmental problems, particularly if protein and mineral intake are not increased at the same time. Again, the horse owner must be able to differentiate between the energy and the protein content of the diet. For growing horses, protein and minerals must be in proportion to the energy in the diet.


Myth: "Corn and Barley Are 'Heating' Feeds."

Corn and barley are sometimes favoured as winter feeds because they are mistakenly thought of as "heating feeds." If "hot" implies high energy, yes, corn and barley are "hot feeds." However, corn and barley are not "hot feeds" if "hot" implies heat production.

Heat is produced in the process of digesting, absorbing and metabolizing any feed. And this heat is useful for helping the horse to maintain its body temperature in cold weather. The greatest amount of heat produced during digestion comes from the breakdown of fibre by the microorganisms living in the horse's large intestine. The higher a feed's fibre content, the more heat produced during digestion. Therefore, more heat would be produced from the digestion of high fibre feeds like hay or beet pulp, compared to heat produced from digesting low fibre grains like corn, barley or wheat. Although low in fibre, even oats produce about 25% more heat during digestion than other grains because of the fibrous hull surrounding the oat kernel.

You can still feed corn or barley in the winter because they contain lots of energy, and energy needs are certainly increased during cold weather as the horse battles the elements. However, if you want to help the horse produce more body heat, feed more hay.


Myth: "Rolled Oats Are Better Than Whole Oats."

If asked, most horse owners will swear that rolled oats are significantly more digestible than whole oats. Most of the studies comparing the digestibility of rolled oats to whole oats have shown that, at most, rolled oats are only 6% more digestible than whole oats. And where digestion of grains counts the most, in the small intestine, the difference is even more minimal between rolled and whole oats. In many cases, the cost of rolling oats far outweighs the small increase we get from processing the oats. The only time when this may not hold true is for older horses, horses with bad teeth, or very young horses, all of whom may not be able to chew the oats adequately enough to break down the hull for better digestion.

So, the next question is "why do I see oat kernels passing out in the manure when I feed my horse whole oats, but not when I feed rolled oats?" To answer this, I encourage people to take their observation one step further—if you poke around in your horse's manure, you'll discover that the undigested "oats" are actually the just the hull (outside, fibrous coating of oats) and not the whole oat itself. The nutritious, starchy part of the oat has been digested, but the hull was not so it passed out in the manure. So the next time you see "oats" passing through your horse's digestive tract, go poke in your horse's manure—see for yourself!


Myth: "Canola Oil Is Toxic to Horses."

I'm not quite sure where this myth originated, but I suspect it started with a misunderstanding about canola itself. Canola was originally developed from rapeseed. Rapeseed does have some undesirable characteristics; however, canola was developed using traditional plant breeding methods to eliminate the unwanted qualities of rapeseed and vastly improve the nutritional quality of the oil. The oil produced from canola seed is now as different from rapeseed oil as olive oil is different from corn oil.

Part of the argument against canola oil is that it is an "industrial oil." True, but so are all other vegetable oils. Corn oil, soybean oil and flax oil are all used industrially to make lubricants, fuel, soaps, paints, plastics, cosmetics, inks, and other products. But just because vegetable oils like canola oil can be used for such things doesn't make the product you buy at the store somehow poisonous or harmful. In fact, canola oil may even be more healthy because it has a better fatty acid profile (more omega-3) than most commonly used oils.

The advice against feeding canola oil to horses may also have ties to the cattle industry. Cattle do not digest fats and oils as well as horses. Too much oil in the diet of cattle can kill the microorganisms in their rumen and decrease their ability to digest feeds. By comparison, oil is digested and absorbed in the small intestine of the horse, so little to no oil reaches the microorganisms in the large intestine. As a result, horses can digest and utilize much higher levels of added oil in their diets (20% of the total diet) compared to cattle (up to 6%).

Adding vegetable oil (canola or otherwise) is a great way to add energy (calories) to your horse's diet. Oils are the most energy-dense feed available. And the calories are provided as fatty acids, not starch, so there is less risk of colic and laminitis associated with feeding large amounts of grain. One cup of oil can replace about 1.5 lbs of oats. Like all dietary adjustments, oil should be added gradually to your horse's ration. Start by feeding your horse ¼-cup per day, then build up to 1-cup over 2 to 3 weeks. For most light breeds of horses, 2-cups is probably the maximum level before digestion may be compromised. The addition of oil also has other benefits. Adding as little as 2 tablespoons of oil may act as a coat conditioner. And oil has been shown to increase the absorption of the fat-soluble vitamins, A, D and E.


Myth: "Blue Salt Is for Cattle Only."

Most horse owners know the various salt products by colour: white, red, brown and blue. In general, "white" salt is plain sodium chloride. "Red" salt is sodium chloride with added iodine (also known as iodized salt, which is similar to our own table salt). "Brown" salt usually contains trace minerals, such as copper, zinc, manganese, iodine and cobalt, and may or may not contain sodium chloride. "Blue" salt contains sodium chloride, iodine and cobalt. While the colours help us identify these products, variations in colour and content do exist—best to read the label.

When buying a salt block, the motto seems to be "red is for horses, blue is for cows." Is blue salt harmful to horses? NO. In fact, the only nutritional difference between red salt and blue salt is the added cobalt in the blue salt. Both contain sodium chloride and both contain iodine. The blue cobalt-added salt was designed for cattle and other ruminants. The bacteria in the rumen use cobalt to synthesize vitamin B12. Similarly, the bacteria in the hindgut of the horse also use cobalt to synthesize vitamin B12. However, horses do not appear to require lots of extra cobalt in their diet to benefit from adequate B12 synthesis.

Although the level of cobalt in blue salt is higher than what they need, it is not harmful to horses. In fact, there has never been a reported case of cobalt toxicity in horses, nor have researchers been able to produce toxicity by deliberately feeding high levels of cobalt. Furthermore, there is no direct link between blue salt consumed by pregnant mares and the subsequent birth of hairless, deformed or stillborn foals. When nutrition is implicated as a cause of these defects, it usually stems from inadequate or imbalanced mineral consumption by the mare during pregnancy. This is especially true of pregnant mares that do not receive adequate iodine or selenium. Blue salt is not the culprit of these neonatal defects.

The other concern with blue salt is the small amount of paint dye used to make the product blue in colour. True, we do not know if this dye has any long-term effects on horses. However, the red and brown salts also contain colouring agents—iron oxide (rust) is used to make red salt red. These colouring agents have been used for years without being harmful to animals.

All horses should be provided with free-choice access to a salt product. Because feeds are also low in iodine, I recommend selecting an iodized salt product—either red or blue salt. However, avoid using "high boot" cattle blocks with horses, as the high iodine content has the potential to cause goitre, especially in foals.


Myth: "Always Feed Hay Before You Feed Grain."

The goal of feeding hay before grain was to slow the horse down so they wouldn't bolt their grain. Secondarily, it was believed that feeding hay first would somehow prevent the grain from overloading the hindgut with too much starch, thereby reducing the risk of colic and laminitis. Unfortunately, for most horses, neither objective was met with this management practice. Most horses are smart enough to figure out that grain is coming, so they turn their noses up at the hay while they wait (impatiently) on their grain. As a result, they still bolt their grain, probably eating more rapidly than they would have if they weren't required to wait.

Furthermore, research has shown that supplying hay to the horse before offering grain does not slow the grain's passage through the digestive tract. In fact, whenever hay is eaten within a couple of hours of the grain meal (either before or after the grain is fed), the grain is flushed through the digestive tract faster. Horses drink more water when fed hay compared to grain. And there is also a large amount of fluid that shifts into the digestive tract to aide in digestion of the hay. All this fluid associated with hay intake is responsible for flushing the grain through the digestive tract. This will occur whether they hay is fed before, with, or after the grain meal. So, offering your horse hay before you give them grain has no advantage over feeding both hay and grain at the same time, or offering grain first and then hay.

The problem with flushing grain through the digestive tract faster is that less starch is digested from the grains in the small intestine, where it should be, and more starch is allowed to pass into the large intestine, where it can cause problems. The only way to avoid too much starch from passing into the large intestine is to separate hay and grain feedings by several hours. Specifically, research has shown that starch digestion can be optimized in the small intestine (where it should be digested) if the horse is left without hay at least one hour before feeding grain. Then, after the grain is fed, you should wait 3 hours before offering hay.

Unfortunately, this practice of separating hay and grain into distinct meals may not be very practical for most people. So, how important is the timing of hay and grain? That depends on how much grain your horse is receiving. For most horses, they aren't being fed enough grain for it to make much difference whether they are fed hay before, with or after their grain. However, if half your horse's diet is composed of grain (>8 lbs/day), you should consider separating grain meals by several hours from hay meals. This will help you to optimize starch digestion in the small intestine, and reduce the risk of colic and founder caused by too much starch escaping to the large intestine. It might also be wise to provide distinct hay and grain meals if you have a horse that has previously colicked or foundered on grain.


Myth: "Horses Must Be Cooled Down After Exercise Before Allowing Them to Drink."

For generations horsemen have been warned against allowing their "hot" horses to drink because of a perceived risk of colic and cold-water founder. However, with the possible exception of very hard galloping, it is safe for horses to drink right after exercise. In fact, recent research has shown that withholding water after exercise may be more of a disservice because it prolongs dehydration. Horses are more likely to drink and replenish fluid lost in sweat soon after exercise when their thirst drive is high, compared to waiting until they are "cool" and have lost interest in drinking.

The caution about hot horses and cold water probably originated from complications experienced by field hunters. At midhunt checkpoints, horses were allowed to drink deeply from frozen streams after hours of galloping and jumping. Although complications were linked to horses drinking while being hot, they likely resulted from winter-frigid water temperatures on top of extreme exertion. Understandably, great gulps of ice-cold water could shock a hot horse's system, but most horses aren't ridden this hard, nor are they given such cold water.

Dehydration can be quite harmful to your horse, so offer water as soon as is practical after your ride. Unless you have been running your horse hard, give him access to tap water right from the start of the cooling out-period. It may take a few minutes for his thirst mechanism to kick in, so allow him to drink his fill and then keep coming back to the bucket as long as he wants a refill. If you ride over long distances, or for prolonged periods of time, stop periodically and allow your horse to drink during your ride.


Conclusions

The list of myths and misconceptions surrounding the feeding of horses can go on and on. These are but a few of the more common ones. Hopefully, by examining these wives' tales from an accurate and nutritionally sound perspective, you have a better understanding of the real truth. I encourage you to continue listening to the advice of other horsemen and rely on their experience. However, be willing to accept that long-held feeding traditions may be wrong, especially as we gain more knowledge from scientific study on feeding horses.


Take-home message

     * There are numerous myths and misconceptions surrounding the feeding of horses.

     * While it's fine to listen to the advice and rely on the experience of other horsemen, do your
        own research! Be willing to accept that traditional feeding practices may be incorrect,
        especially as we gain more knowledge from scientific studies on feeding horses.

     * Straight alfalfa is safe if fed correctly; wheat bran is not a laxative; beet pulp is a nutritious
        feed that doesn't have to be soaked; blue salt is okay for horses; protein does not cause a
        horse to be high-spirited; there is little advantage to rolled oats over whole oats; and more!


Suggested Reading

1. Evans, J.W., A. Borton, H. Hintz and L.D. VanVleck (1990) The Horse. W.H. Freeman Co., New York.

2. Geor, R.J. (July 2001) Chilling Out After Exercise. The Horse. pp 89-94

3. Harris, D.M. and A.V. Rodiek. (1993) Dry matter digestibility of diets containing beet pulp fed to horses. In: Proc. 13th Equine Nutrition and Physiology Symposium. pp 100-101.

4. Lewis, L.D. (1995) Equine Clinical Nutrition. Williams & Wilkins, Baltimore.

5. Lewis, L.D. (1996) Feeding and Care of the Horse (2nd edition). Williams & Wilkins, Baltimore.

6. Meyer, H., S. Radicke, E. Kienzle, S. Wilke and D. Kleffken. (1993) Investigations on preileal digestion of oats, corn, and barley starch in relation to grain processing. In: Proc. 13th Equine Nutrition and Physiology Symposium. pp 92-97.


About the Author

Author Lori K. Warren, Ph.D., P.A.S., joined Alberta Agriculture, Food & Rural Development as Provincial Horse Specialist in May 2000. She received her M.S. and Ph.D. in Equine Nutrition and Exercise Physiology from the University of Kentucky. Her research focuses on the nutrition of performance horses and forage utilization by young growing horses.

This information was presented at, and appears in the Proceedings of, the 2002 Alberta Horse Breeders and Owners Conference.

^{This information is maintained by of the Horse Industry Section of Alberta Agriculture in conjunction with Sylvia Schneider at Pondside Web Productions.}