Revised:  09/14/2012

Ask the Expert -- Nutrition














Grain and Feed Mixes



Can beet pulp cause colic?

I have a bit of a dilemma about beet pulp. My vet says that there is some new research about it causing stomach stones and colic if fed on a daily basis. He recommends feeding beet pulp every other day or so. I have been feeding soaked beet pulp to my older horse for over a year now with no problems, but I am concerned that it might become an issue. Could you tell me if you have read or done any research on beet pulp, and what the findings are?


I am not aware of any reports of beet pulp causing stomach stones or colic if fed regularly. I usually hear about the benefits of feeding beet pulp regularly!


Beet pulp is very high in fiber. If fed without added molasses it will not greatly increase the caloric density of the diet. Most horses that can’t consume enough hay in their diets do well from eating beet pulp to help replace the missing fiber. Obese horses or ponies that do not need grain yet need supplements in their diets can have a small amount of moistened beet pulp to serve as a carrier. Overall I particularly like beet pulp because it is a universal feed. Keep in mind that there is also a myth about moistening beet pulp. There have been studies done on beet pulp based feeds (up to 50 %) and no problems have been found with feeding it dry. The benefits of feeding it moistened include the ability to make it sticky to prevent sorting out of supplements, etc. Moistened beet pulp also increases water intake in horses that are prone to dehydration, especially in strange environments, etc.


So overall I would not be concerned at all about feeding beet pulp; I actually frequently recommend it.


Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.



Is a warm bran mash safe for arthritic horses?

Is it safe to feed a warm wheat bran mash on the weekends to a 7-year-old horse with arthritis? I hear mixed things about how good it is for them and that it can disrupt a horse’s calcium/phosphorus levels. My mare does not have any digestive problems- the bran is just given as a treat in colder weather.



That is exactly what bran mash is for them…a treat. It is really neither good nor bad if given on occasion. It is more of a “comfort food?for both them and us. It will not throw off their nutrition if only given on weekends or before hauling or on cold days. It usually just makes us feel better to give our horses something warm to eat, much in the same way a bowl of hot oatmeal feels good to us on a cold morning.


Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.



Can corn cause laminitis?


A friend told me that the worst thing to feed horses is corn. She claims it is the leading cause of laminitis. Is there any truth to this statement?



This statement is not completely true, but it is also not completely false. Corn is not the leading cause of laminitis, and when fed correctly it does serve a purpose in feeding horses. However, if not fed correctly it can cause problems.


Corn contains a lot of starch, which is rapidly broken down into glucose and used for energy. This type of energy is used up very rapidly and gives many people the impression that their horse is acting “hot.?This is why corn is often thought of as a “hot feed.?Picture, for example, a kid who has just eaten a lot of candy, and has a lot of energy (aka a “sugar high?. What happens next? They get very tired very quickly, or “crash.?The same thing happens to horses that have consumed a lot of starch. They have a lot of energy all at once and then they crash. If a lot of starch is fed to a horse that is overweight or at high risk for metabolic problems, it could cause colic or laminitis.


Many sweet feeds containing corn have only about 20-30% corn. For most horses whose diet consists of mostly pasture or hay, adding a few pounds of sweet feed to their total diet should not cause problems. Keep in mind that overweight horses should not have any sweet feed in their diet, let alone much corn. But most horses on a good quality hay (or other forage) diet should not have a problem with a limited amount of sweet feed or other grain supplement.


Answer provided by Carey Williams, Ph.D., Equine Extension Specialist, Rutgers Cooperative Extension.



Is it okay to feed corn and wheat to horses?

How do you feel about feeding 50% sweet feed and 50% whole corn kernels off the cob? Where I live shelled corn is abundant and inexpensive; therefore I would like to add it to the sweet feed. I normally feed 5-6 pounds per horse in the cooler months and pasture the horse when the season allows. I don't want to colic the horses on the corn. Also, can I feed wheat since that is also readily available?


Whole corn is an acceptable feed for horses as long as it is not moldy and is introduced slowly. If a horse has dental problems they may not be able to chew it effectively. It is very energy dense. One pound of corn contains about 25% more calories than the average sweet feed, which also usually contains corn in addition to many other less energy dense ingredients. The amounts you are feeding should not be a problem if divided into two separate feedings. If you are group feeding the horses I would worry about individuals getting more than they should. They should also have hay if pasture is not available and free access to salt and water should always be provided.


Wheat is much less digestible and not very palatable to horses. It should be processed (flaked and/or steamed) to increase digestibility. I'd prefer corn to wheat. That being said, the concern regarding mold in corn is very serious - the type of mold that commonly affects corn can kill a horse. Make sure you get corn that is guaranteed not to be moldy. If the seller can not test it you should contact your local county Extension agent to see if they can help you get it tested.


Answer provided by Sarah Ralston, VMD, Ph.D., dACVN, Rutgers Cooperative Extension.



Is it safe to feed cottonseed to horses?

I was wondering why cottonseed shouldn't be fed to horses? Does it cause blindness? I have fed a mixture in the past that contains 10% cottonseed without any adverse reactions over about a 4-month time period in the winter.



There have been many questions regarding the adverse effects of feeding cottonseed to horses. Cottonseed meal is the most popular form of cottonseed fed to horses. Raw cottonseed and cottonseed meal contain a substance called gossypol that interferes with digestion. Therefore cottonseed is particularly undesirable for feeding foals. Adult horses can tolerate the gossypol if fed cottonseed in moderation. Monogastrics (e.g. horses, pigs and poultry) seem to be more affected by gossypol than other species. Research in other species has shown cottonseed meal to decrease sperm production in males and slow growth in young if fed in high levels.


It was at one time thought that blindness in cattle was caused by gossypol. I have never seen proof of cottonseed as a factor in night blindness. However, cottonseed meal and hulls are low in vitamin A, which plays a significant role in vision. It is a major vitamin requirement for horses, and if a horse is experiencing a vitamin A deficiency one of the most common problems experienced is night blindness.


The nutrient composition of some feeds can be altered by different processing methods. Feeds like corn, for example, can be fed whole, ground into a meal, or even made into silage. There is a difference in the digestibility of cottonseed if it is fed raw or if it is made into a meal but this does not seem to affect its vitamin content. Moreover, cottonseed oil and its gossypol can be removed from cottonseeds by extraction with ethyl ether. It has been shown that using cottonseed with 0.2% or less gossypol has had no toxicity effects.

Cottonseed meal, at about 40 % protein, is ranked second to soybean meal in high protein supplemental feeds for horses. It also has half the lysine of soybean meal. About 25% of the protein source in a ration can be made up of cottonseed meal before you run into problems. Therefore, it is recommended that high quality cottonseed is combined with other forms of protein and lysine supplements.


If you choose to feed cottonseed, follow these guidelines:

  1. Make sure the cottonseed doesn’t comprise more than 25% of your protein source

  2. Supplement with either a source of protein that is high in lysine (such as soybean meal), or with a pure lysine source.

This answer was prepared with the help of Nicole Fiorellino, Animal Science Research Student at the School of Environmental and Biological Sciences, Rutgers University.



Are distillers grains a good feed for horses?


Can you tell me if there is any recent information on feeding distillers grains to horses? Are they a good, safe feed for horses?



Distillers grains (the solids remaining after fermentation in brewing and distilling processes) are a good protein supplement to the horse’s diet, but not recommended in large amounts. They are typically high in protein (25-30%) and their respective amino acids, and they also have a moderately high level of fat (5-10%) and B-vitamins.


The problem is that many of these grains don’t have adequate, balanced levels of minerals for horses. For example, horses require a 2:1 calcium/phosphorus ratio (two parts calcium to one part phosphorus). Most distillers grains contain more phosphorus than calcium (1:5 or higher). Feeding distillers grains in large amounts could throw off the mineral balance of the diet. Typically, a daily ration containing 10 to 15% distillers grains (about 2-4 lbs per day maximum for an average 1000-lb horse) will adequately provide supplemental protein without affecting the mineral balance.


I have found two recent publications on the use of distillers grains in horses at Studies along these lines are ongoing; more research should be published within the next year.


Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.



Is feeding rice bran and barley safe for a foundered horse?

Is it okay to feed soaked barley and rice pollard to a horse that has foundered in the past? I have recently started feeding these feeds. My horse is looking great and putting on weight, but I just began to wonder if this diet was safe for him. I am working at feeding split in two feedings 2 kg (before soaked) barley, 2 kg of rice pollard with mixed chaff and Equilibrium and cup of soy powder plus hay. Your help would be very much appreciated.


Rice pollard (known as “rice bran?in the USA) is a high fat (19 % or higher) and fiber supplement. Barley, especially if soaked, has the lowest starch/sugar index of the grains. If your horse has not foundered on this regimen I doubt if he will in the future! However, 2 kg of rice bran a day is a bit much. It is also very high in phosphorus. Unless your hay is Lucerne (alfalfa) or another legume mix, or your rice bran is a “stabilized?product (which will have additional calcium added to it), you run the risk of feeding more phosphorus than calcium. The Equilibrium Mineral mix does provide some extra calcium, but I'd suggest strongly backing down to 0.5 kg rice pollard per feeding. Hopefully you are feeding Equilibrium in the recommended amount of only 1 scoop per day - it is very high in a lot of minerals and certain vitamins that can be toxic if fed in excess. Also, don't let your horse get obese. If he starts getting too fat you should decrease the barley and rice bran accordingly. Obesity does predispose to laminitis/founder.


Answer provided by Sarah Ralston, VMD, Ph.D., dACVN, Rutgers Cooperative Extension.



Are hydroponic (germinated) barley and other grains good for horses?

I have been reading up on using hydroponic fodder systems to grow feed for horses. Most of the information has been on sprouted barley and I am wondering what the nutrient composition of this feed might be and if it would be good for horses? Are there other types of grains which could be grown this way that would be better suited for horses? Are you aware of any research that has been conducted in this area?


Sprouted barley grains can be fed as loose feed or just feeding the greens as forage. The picture to the right shows sprouted barley that is fed to horses in Europe.


Research on feeding sprouted grains to horses is sparse. Click here for a link to an Australian Review of Hydroponic Fodder Production for Beef Cattle.  This summarizes much of the research up to 2003. Many trials show no advantage to feeding sprouted barley over grain barley; in fact, the cost of growing sprouted barley hydroponically created an economic disadvantage. There are also research trials that have been conducted with pigs and poultry, summarized here. There was no research available on using this technology in horses. This Extension Fact Sheet reviews various sources of research (excluding horses) on feeding sprouted barley to livestock.


A concern is that moist materials run a greater risk of becoming moldy. This is a common problem in hydroponic fodder systems. Ruminants such as cows are not as affected by mold as horses, which can easily become very ill or even die from eating small amounts of mold.


Even in the cattle feeding trial, sprouts were used as a supplement to pasture. It has also been found that the grains lose nutrients during the sprouting process. The younger the sprout, the higher the nutrient value (i.e. energy, protein, and digestibility); therefore, feeding them earlier is preferable.


Germinated barley is being fed to horses in Europe (see EDHYA Form) and can be made at home by horse owners. If you do try producing this, then the utmost care must be taken to avoid mold and toxins. There is still no research that has been conducted on this feed product for horses; this answer is just stating the facts. The Equine Science Center is unable to provide feeding recommendations without scientific evidence that it is safe and effective.


*Photo by Carey Williams



How do you feed millet to horses?


I know that millet is good for the bones because it is rich in silica. How do you feed it? Does it have to be cooked or can horses eat it raw?



Millet isn't typically fed to horses in the United States. Even though it has high levels of silica, due to its hard outer shell it needs to be finely crushed in order for the horse to process the grain. The horse will not benefit from eating it whole.


There is another concern with feeding millet to horses, however. It contains a glucoside (a plant-derived chemical derived from sugars) called setarian, which causes considerable kidney irritation and excessive urination in horses. This can be especially problematic in horses with existing kidney problems.


Feeding an adequate level of calcium in the correct ratio with phosphorus (2:1) will provide adequate nutrition for young horses establishing proper bone growth. Older horses that have finished growing don’t need to establish bone, just maintain it. This can be done with a balanced diet and no less than a 1:1 ratio of calcium to phosphorus.


Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.



Are oats good to feed to horses?


I have considered switching my horses from a typical sweet feed to straight oats. Is this okay to do? What would I have to worry about, if anything?



Oats are the most common cereal grain fed to horses. They are higher in fiber than most grains and not too high in sugars and starches (this is the reason why grains and sweet feeds have gotten such a bad name recently). If fed with good quality grass hay they should meet all the requirements for a mature horse up to light work. However, if you have a horse that is intensely working you may need a vitamin/mineral supplement and possibly an added energy source (like corn oil or rice bran) if they start losing weight while in training. If you have a pregnant or growing horse they will need an additional vitamin/mineral supplement to balance everything out - especially the calcium and phosphorus. Also, they would need additional protein in this ration. A good way to add the protein is to add alfalfa of some sort (hay, cubes, pellets, etc.) to the diet. This will provide protein along with the extra calcium needed. Another good protein source is soybean meal.


Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.



Are oats high in sugar?


My new barn manager had a question the other day about oats. A nutritionist on RFDtv stated that oats are really high in sugar and should not be fed before competition. I've never had a horse get hot on oats.



In regard to oats, the pure kernel without the hull has about the same amount of starch as an equivalent weight of corn, and oat starch is more digestible than corn starch. Therefore blood glucose will rise more quickly after a pound of oat starch compared to a pound of corn starch. That being said, if one feeds crimped or whole oats, the starch content per pound is diluted out by the indigestible hull and, if feeding by volume, not weight, a one pound "scoop" of oats weighs only 1/2 to 3/4 as much as a similar volume of cracked or flaked corn or rolled barley.

As far as feeding before a competition, Europeans consider oats a "hot" feed (Ergo the phrase "feeling his oats"!) perhaps because they tend to feed the super clean "race horse" oats that have a portion of the hulls removed. This might be desirable for race horses but not for an equitation or pleasure show horse. The behavioral effect, if any, will probably not persist for more than an hour or two after feeding, so one might miss this effect if the breakfast meal is fed three to four hours before riding.

For foundered or insulin resistant horses, the main concern is by-pass starch getting into the cecum and causing problems. That would be more likely with less digestible starch such as corn or barley, than with the highly digestible oat starch.



This answer was written by Sarah Ralston, VMD, Ph.D., dACVN, Rutgers University, Equine Science Center



What is the best way to feed soybeans to horses?


I understand soybean meal is a good source of protein for the older horse. I have soybeans direct from the farmer; can I grind my own meal and feed it? If so, how do I determine the quantity?



Raw soybeans contain a trypsin inhibitor that negates their good protein value somewhat. You need to roast or boil them to inactivate it. They should also be soaked in water overnight before cooking them.


Whole soybeans also contain a fairly high amount of fat, which is an excellent source of calories too. Commercial soybean meal is what is left after soybean oil (aka vegetable oil) is extracted. Feeding ?cup of the whole or ground beans twice a day for an average sized horse (about 1000 lbs) will put a really nice "bloom" on your horses.


This answer was written with the help of Sarah Ralston, VMD, Ph.D., dACVN, Rutgers University, Equine Science Center.



Is a grain mix with corn, oats and soybeans okay for my young horses?


I am currently feeding a grain mix that is equal parts corn and oats with roasted soybean added to make a 16% protein mix with a small amount of molasses to keep the dust down. I feed grass hay and a complete supplement. I have a breeding farm with 48 horses and want to keep feeding costs down. I was told that corn has too much Omega 6's and that more oats and flaxseed for more Omega 3's should be added. Would this formula be appropriate for foals: Oats 700 lbs, corn 300 lbs, roasted soy 100 lbs plus supplement. Should I top dress a cup of flaxseeds or meal?



Corn is a perfectly acceptable, high energy grain to feed to horses. Concern about the Omega 6 content is regarding corn oil. However, the actual research on which the concern is based used significantly high amounts of the pure oil. It is also not necessary to add flaxseed.

Roasted soybeans will add more protein and a bit more fat to the ration. But if you are trying to keep costs down, I would strongly suggest adding alfalfa pellets or meal to the grain mix for broodmares and young stock to provide extra protein and calcium, which is currently lacking in your mix. You could totally replace soybeans with alfalfa. It depends on how expensive alfalfa is in your region. If you are getting your feed custom mixed, considering the price of corn often fluctuates, if you made a mix of 250 lbs oats, 250lbs corn and 500 lbs of 17% protein alfalfa pellets or meal with 1 to 2% molasses, you would have a mix that provides 16% protein, 0.8% calcium and 0.3% phosphorus which is right at the needs of your breeding and growing animals.

Feeding it at the rate of 0.5 to 1.0 % body weight divided into two or three meals a day with free access to grass hay should meet the horses? nutritional needs. No supplements other than salt and water are needed.



This answer was written with the help of Sarah Ralston, VMD, Ph.D., dACVN, Rutgers University, Equine Science Center.


How do 'ration balancers' work?


I have a Gypsy Vanner stallion that is overweight and suffers from chronic laminitis. It was recommended that I stop feeding grain and feed a "ration balancer.?My horse is currently on 1/2 scoop of a low carb grain, ?cup of corn oil and a handful of sweet feed per feeding and a few supplements. I know my horse has to lose weight, but I am at a loss as to how to accomplish this short of starving him. Do ration balancers work and are they a good choice for my horse?



It does sound like a ration balancer is a good choice for your horse. The principle behind the ration balancer is to provide the appropriate amount of protein, vitamins and minerals for a horse without providing extra energy (calories). Most average-sized horses with a good quality grass hay diet only usually require one pound or less per day of a ration balancer to meet their needs. If more energy is needed, these can also be fed in combination with a sweet feed or other grain product in low amounts as well.


For your horse, the grain-based feed is contributing to the weight problem and can be discontinued. You should also remove the oil from the ration, which is pure energy and definitely adding unnecessary calories. Since a ration balancer is completely fortified and designed to be fed with only hay or forage, the extra supplements could disrupt the horse’s vitamin/mineral balance, depending on what type of supplements they are.


To encourage weight loss, continue feeding the hay used now, but it should be weighed out each feeding to make sure the horse gets no more than 1.5% of its body weight per day (assuming it is about 1,000 pounds, no more than 15 pounds) divided into three feedings so the horse does not go for prolonged periods without feed. Also consider the pastures: lush, high-quality pasture can provide an enormous amount of energy and could require that the horse wear a grazing muzzle when turned out. You can then provide one pound of a ration balancer per day (split into two feedings of a half pound each). In approximately 1-2 months, one should start to see a decrease in weight. If the horse can be exercised, one might see the change sooner; however, healthy weight loss is a long term process. Keeping a record of weight (using a weight tape) and body condition is a good idea, and if no progress is seen after several months, decrease the hay portions even more. Once the horse reaches the desired body condition/weight, increase hay intake to 2.0 to 2.5% of its body weight. Grazing in the spring and late fall, however, should still be limited or not allowed due to this horse’s chronic problem with laminitis.




The material provided on this site is for educational purposes only and is not intended to diagnose, prevent, or treat any illness. Any recommendations are not intended to replace the advice of your veterinarian. Any products mentioned are not intended to diagnose, treat, cure, or prevent disease. Mention or display of a trademark, proprietary product, or firm in text or figures does not constitute an endorsement by the Equine Science Center or Rutgers University and does not imply approval to the exclusion of other suitable products or firms.







 Search this site

 News and Features


Health Notices

Ask the Expert

Make a Gift

For the Love of Horses

Ryders Lane farm

Equine Science 4 Kids!


Alumni News

Horse Management Course

Equine Scholarships at SEBS

Young Horse Teaching and Research Program






If Adobe Acrobat Reader 5 or greater is not already installed in your computer you may download it for free.
Please follow the link below.

Download Acrobat?/span> reader





?2009 Rutgers, The State University of New Jersey
Items may be reprinted with permission from the
Director of the Equine Science Center:

The Equine Science Center is a unit of
Rutgers New Jersey Agricultural Experiment Station.