By Martin W. Adams, PhD, PAS – Equine Nutritionist for Southern States
Compared to most classes of livestock, there seem 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 horse owner. 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”
Feeding a bran mash has been recommended as good for horses. The reason for this thinking is wheat bran will function as a bulk laxative in humans, and also in swine. Both people and pigs 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. Since horses consume a high fiber diet, it doesn’t affect them as far as being a source of beneficial fiber.
Using bran mash as a weekly ‘cleanser’ or laxative is common practice among horse owners. It is believed to add bulk to the stool, help with hydration, assist digestion, and is a good source of fiber. Providing a weekly bran mash could dramatically alter the daily feeding program and disturb the normal population of microorganisms in the hindgut. Dumping wheat bran into the digestive system can cause a sudden die-off of some bacteria and force overgrowth of others. This shifting bacterial population in the gut could result in diarrhea, leading one to believe that wheat bran acted as a laxative. Remember, routine feeding of the same feeds every day is the best way to avoid digestive upset in horses.
Research shows that wheat bran does not have a laxative effect or soften manure in the horse. A study conducted at Cornell University in which 50% wheat bran was added to a diet of hay and grain, found that fecal moisture was no different between horses receiving wheat bran than those on a controlled, wheat bran-free diet. While wheat bran gives manure a bulkier appearance, it’s because the fiber in wheat bran is not very digestible. The horse is dumping a bigger manure pile because most of the wheat bran was not digested, not because it contains more water.
While wheat bran has more fiber than corn and about the same amount as oats, and it has less fiber than hay. Providing plenty of hay is the best way to keep the digestive tract full of fiber and the horse’s digestive system well hydrated. The amount of dry hay a horse eats is positively correlated with the amount of water it drinks,
Keep in mind that wheat bran is fairly high in starch and the horse is pretty sensitive to dietary changes in the amount of starch fed. So substituting a bran mash for the horse’s regular feed could cause a digestive upset. This is not a good way of “cleaning out the system” and is actually a way to cause diarrhea or 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.
“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 for Wintertime Feeding”
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. It has been shown that feeding a concentrate high in soluble carbohydrates (starch and simple sugars) results in more excitable behavior compared to feeding a low soluble carbohydrate concentrate. 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 not 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, also contains significantly more calories per pound, so an excess amount of calories could be fed if 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 fairly quickly, but unless it contains a large amount of fine material, it can’t soak up saliva quickly enough to cause a choke. Choke associated with feeding 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 not likely that dry beet pulp will rupture the horse’s stomach. The horse’s stomach holds 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. If your feed container is a bucket suspended from the rail in the stall, or any container elevated off the ground, wet or soak beet pulp before feeding to prevent choke, which is more likely with any dry ingredient that is fed in a position where the horse can’t properly chew.
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 or a few weeks to months beyond its manufacture date will likely be dry as the water content in the feed will evaporate over time, so add some water to the feed if it appears a little dry or dusty. 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 two hours before feeding grain. Then, after grain is fed, you should wait at least two hours before offering hay. Unfortunately, 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 low 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 hay from a raised feeder and grain from a bucket on the rail can result 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.
Again, management and time constraints can prevent the best practices from being implemented, but keep this in mind when you have a problem with a particular horse and you may be able to fix it with a simple feeding management change that would be a healthier option.