Horse Feeding Myths and Misconceptions
Dr. Martin Adams, PAS – Equine Nutritionist for Southern States
Compared to most classes of livestock, there seems to be more myths and misconceptions when it comes to feeding horses. Many of these feeding myths appear to be long-held traditions that have been passed down from horse owner to horse owner. These myths or misconceptions are likely due to the fear of harming the horse, a lack of understanding of the feedstuff or the feeding practice, or thinking that the horse's digestive system or nutrient requirements are similar to that of the human horseman. The old adage that "It's always been done this way!" can be a powerful argument in keeping a tradition alive, in spite of scientific fact. We now have some scientific evidence that some of these "horse tales" are not true and may be harmful to the horse, so let's review some of the most common horse feeding myths and misconceptions.
"Bran Mashes are Beneficial for Horses"
Providing a bran mash or feeding wheat bran was likely thought to be good for horses as it will function as a bulk laxative in humans, and also in swine; both are species who normally consume a low fiber diet, and even the small amount of fiber present in wheat bran will have a laxative effect in people and pigs. Since horses consume a high fiber diet, it doesn't affect them as far as being a source of beneficial fiber. Research has shown that adding wheat bran to the horse's diet doesn't have a laxative effect. The moisture content of horse's manure was similar whether the horse received wheat bran in their diet or not. In fact, wheat bran is fairly high in starch and the horse is pretty sensitive to dietary changes. So substituting a bran mash for the horse's regular feed could cause a digestive upset and loose manure will result. This is not a good way of "cleaning out his system" and is actually a way to cause colic in your horse. Wheat bran is also much higher in phosphorus than calcium, so long-term feeding of wheat bran without balancing the diet can result in mineral deficiencies. So provide clean, fresh water, good hay and a well fortified horse feed and you will be providing the best nutrition program for your horse.
"High Protein Diets Cause Development Problems in Growing Horses"
Nutrition, exercise and genetics all have roles the development of healthy bone development in the growing horse, and these same factors are linked to the occurrence of developmental orthopedic disease (DOD). The 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 of DOD in the 1970's but later studies have shown that not to be true. Feeding more protein than the growing horse needs does not increase the growth rate above the growth rate achieved when the diet just meets protein requirements. And restricting protein will not result in improved bone growth, and can actually be harmful by decreasing feed intake, growth rate and skeletal development. However, overfeeding energy will result in DOD problems, especially if protein and mineral intake are not increased at the same time. For growing horses, protein and mineral intake must be in proportion to the energy level of the diet.
Corn, Barley and Oats are "Heating" Feeds and Good to Feed in Winter"
Heat increment refers to the amount of heat produced due to the digestion, absorption and metabolism of feedstuffs in the horse's body. Heat increment is greater for fibrous feedstuffs like hay that must be fermented in the large intestine of the horse compared to feedstuffs high in starch like corn, barley and oats. So feeding more hay during winter weather would be more advantageous to the horse. A diet with more hay would generate more heat and assist with maintaining the horse's body temperature, because during cold weather heat is lost from the horse's body at a greater rate. The horse's metabolic rate and calorie loss is greater during cold weather as it tries to maintain normal body temperature.
"High Protein Feeds Make My Horse Hot"
There is no research to show a connection between feeding excess protein and "hot" behavior or excitability in the horse. There have been studies showing that a diet high in soluble carbohydrates (starch and simple sugars) that are responsible for a high glycemic response (rise in blood glucose and insulin) is related to more excitable behavior. There is also research to suggest that overfeeding grain will also increase excitable behavior, whether that is due to an increased glycemic response or simple energy excess is now known. It may be that horse owners with a performance horse tend to select a feed with a higher soluble carbohydrate content or feed an excessive amount of grain when they select a higher protein feed. Also, switching a horse to alfalfa hay, which contains more protein compared to grass hay, can also contain a significantly higher caloric density, so an excess amount of calories could be fed if a high quality alfalfa hay was fed compared to a lower quality grass hay. Feeding more protein than the horse requires results in the protein above the required amount being used for energy production and results in more heat and ammonia produced in the horse's body. Whether this can result in excitable behavior in the horse has not been proven in a clinical study.
"Beet Pulp Must Be Soaked Before Feeding or Your Horse Will Explode"
There have been persistent myths that if beet pulp is not soaked before feeding, it will swell and block the esophagus or rupture the horse's stomach,. Because beet pulp seems to "grow" or expand its volume greatly after water is added, the idea is that beet pulp could soak up enough saliva or gastric fluid so quickly that it could expand enough to occlude the esophagus or rupture the stomach. Beet pulp may soak up water like a sponge, but it can't soak up saliva quickly enough to cause a choke. Choke associated with beet pulp is usually associated with a rapid eating rate (bolting) and inadequate chewing, inadequate access to water, a raised feeder (not at ground level) with inadequate chewing, and particle size (pelleted and finely shredded beet pulp are the worst for causing a choke).
It is also not likely that dry beet pulp will rupture the horse's stomach. The horse's stomach hold 2 to 4 gallons, which has the capacity to hold 4.5 to 9.5 pounds of dry beet pulp, which is much more than most horse owners would feed in a single meal. And most food that travels into the stomach passes into the small intestine in 15 minutes or less, and it normally takes longer than that to thoroughly soak beet pulp for it to fully expand. The 40 to 50 gallon capacity of the horse's digestive system is more than sufficient to handle even a large meal of dry beet pulp. And the horse will voluntarily drink enough water to process any feedstuff that is low in moisture content, like hay or dry beet pulp, as well as adding water from additional salivary flow with more chewing required for fibrous feedstuffs. So you don't have to soak beet pulp prior to feeding. Research conducted at several universities fed rations with up to 50% dry beet pulp content of the diet to horses without choke or other problems. Also, many tons of shredded beet pulp are added to horse feeds and fed right out of the bag each year with few problems. If you don't soak beet pulp before feeding, make sure that you feed close to ground level to provide proper chewing action and provide the horse with as much fresh, clean water as desired.
Although soaking beet pulp before feeding is not necessary, there are some good reasons for soaking before you feed it. Soaking beet pulp makes it easier to chew, especially for older horses with missing or worn teeth. Soaked beet pulp is more palatable and provides a good medium to add supplements or medications. If your horse bolts his feed, doesn't have adequate access to water, or if your feeder is not close to ground level, soaking beet pulp before feeding will reduce the chance of choke. And any manufactured horse feed containing beet pulp or other added fiber that has been out of the bag for awhile will likely be dry as the water in any added molasses will evaporate over time, so add some water to it. This will improve its palatability and reduce the risk of choke.
"Always Feed Hay Before Grain"
The idea of feeding hay before grain was to slow the horse's eating rate down so it wouldn't bolt its grain. It was also believed that feeding hay first would prevent the grain from somehow overloading the hindgut or large intestine with too much starch. Unfortunately, neither objective is reached for most horses with this practice. Most horses figure out that the grain is coming after the hay so they don't eat their hay and wait for the grain, and get impatient in doing so. As a result they may eat their grain even more rapidly or "bolt" their grain, increasing the risk of choke and colic. Research has shown that providing hay to the horse before offering grain doesn't slow the grain's passage rate through the digestive tract. In fact, when hay is consumed within a few hours of the grain meal (either before or after the grain is fed), the grain is flushed through the digestive tract faster. This is because horses drink more water when fed hay compared to grain, more chewing results in more secretion of saliva, which is mostly water, and the horse needs to replace that water loss and drinks more. Also, there is a large fluid shift into the digestive tract to aid in the digestion of hay. So the extra water consumption and fluid shift due to hay consumption is responsible for flushing the grain through the digestive tract. This occurs whether hay is fed before, with, or shortly after the grain meal.
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, which is the practice that most horse owners follow. The problem with grain being flushed through the digestive tract is that less starch is digested from the grain in the small intestine, and more starch passes 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. 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 for at least one hour before feeding grain. Then, after grain is fed, you should wait at least two hours before offering hay. Separate feeding of hay and grain over this time period is not very practical for most horse owners.
So how important is the timing of feeding hay and grain? It depends on how much you are feeding and the starch content of your grain or horse feed. For most horses that are fed no more than 0.5% of their body weight per feeding (i.e. 5 pounds for a 1,000-pound horse or 6 pounds for a 1,200-lb horse) it won't make any difference, so don't worry about feeding hay and grain at the same time. If you are feeding larger amounts of grain (more than 5 or 6 pounds) per feeding, consider going to a controlled starch or fiber-based horse feed (maximum of 20% starch). And if you have a horse with a chronic history of gas colic or founder, switch to a lower starch feed and you may even consider providing distinct time-delayed hay and grain meals to minimize the amount of starch escaping to the large intestine.
"Feeding in Raised Feeders is Healthier for My Horse"
How we feed horses can be as important as what we feed. Horses are designed to eat off the ground which is evident in the fact that the lower jaw slides forward into proper grinding position only when its head is down. Eating from a raised feeder results in improperly chewed food, improper tooth wear, decreased saliva, increased incidence of choke, and respiratory issues from more inspired dust and mold in hay and grain.