Equine Nutrition: Fact and Fiction

By Kimball Lewis

During the past 20 years as an equine abuse and neglect specialist, I have attended to, assisted with and directly investigated many hundreds, even thousands, of neglect and abuse cases relating to horses. The very word 'neglect' is a vague and often uncertain term. What constitutes neglect to one person may not be so clear to the next. Likewise, many enforcement agencies typically charged with the investigation of these matters have equally uncertain or differing views on what does or does not rise to the level of neglect. What is certain however is that nutrition is at the core of 90 percent of these cases. The other ten percent are equally shared by lack of proper veterinary care and inadequate shelter.

What is proper nutrition, and how do we, as horse owners, simplify what seems so open to interpretation? We will, in the very limited space of this article, attempt to make clear the formula to successful feeding. In fact, it may be an injustice to attempt to oversimplify something so complex, however, when broken down in easy-to-grasp segments,, we will discover that fundamental feed management is easily achieved.


No Brainer, you would think? Not! Too many horses are deprived of water for too many reasons, none of them good ones. Limiting water so a horse doesn't urinate in his stall is abuse. Many horses have died as a result of renal failure and other complications. There was a famous horse trainer, who is still featured in many magazines each month, who killed a horse through water deprivation. He was teaching this as a tool in the training process and one of the horses died as a result of complications arising from this absurd method.

The practice of depriving an animal of water for any purpose, whether it be for training or simply because someone is not industrious enough to clean the stalls, is legally defined as neglect.

In all states and jurisdictions, it is a criminal offense to deprive an animal of necessary substance and water is included in this. There are no exclusions or exceptions to this law. Religious groups and professional trainers are not excluded from the law and are equally subject to prosecution. During the past couple of decades I have seen three glaring forms of abuse that should not be tolerated. The first is when a person owns a horse and is too lazy to clean the stall so s/he intentionally limits water intake so the horse will not urinate as often in the stall. The second is water deprivation as a training tool. The third is the limitation of water intake in pregnant mares for the purpose of concentrating estrogen in the urine. All three of these practices are clearly defined by law as criminal offenses. There is no latitude for individual interpretation.

Water is the cornerstone of diet. One can go for days without food, but a lack of water will lead to death, or at least secondary complications, much faster. So here it is. Know this and stick by it: Provide clean water at a rate of at least 1 gallon per 100 pounds of body weight per day. Period. You can go to web sites and read all manner of complicating formulas about .08 gallons at work and .03 gallons at rest, but that is nonsense. One gallon per one hundred pounds of body weight is what you must make available to your horse each day. They'll drink when they want and won't drink when they aren't thirsty. We don't need some herd management expert from Purina to give us a seminar on the matter.

Sticking one five-gallon bucket in a stall once a day will not get the job done; FREE CHOICE water is absolutely critical to your horse's good health and digestive process. So take care of his water needs before you even think about feed management, because water is the foundation. This is not so difficult - 50 to 100 gallon tanks are nice; better yet is a stream running through your property. We are fortunate in this regard as we have a stream that is fresh and flowing year round.

If you are like 80% of horse owners who live in areas where there are dramatic temperature variations, you already know that ponds can freeze over in the winter and become stagnant in the summer. Again, the water tank is your best option, and during warmer months you'll need to take a scrub brush and clean it out weekly, and during the winter you'll need a tank heater to keep it from freezing over.

Forage Management


This is obviously the ideal situation. If you are in a situation where you have several horses and horse property with pasture, then pasture management is an important issue. Key to your horse's health is the obvious need for adequate forage. For thousands of years, free roaming horses have grazed on their own in a free-choice feeding environment arranged by nature. All of the mineral and protein needs were adequately acquired through their own feeding habits. Because we have placed the horse in a captive environment, it falls to us to replace what nature provided on her own.

In the pasture setting, two things need to happen. First, ensure adequate forage through rotation. Second, follow a horse-to-acreage ratio.

Rutgers University studied 40 horse properties throughout New Jersey. For you readers not familiar with New Jersey or who only think of the turnpike and Newark, guess again. This state has the most horses per acre of any state in the US! I was amazed during several visits to the USET in Far Hills to see the amount of open land and riding area. In any event, of these 40 properties studied, 90% were overstocked and subsequently overgrazed.

Granted, there will be regional considerations related to the climate and altitude where you live, but as a rule of thumb consider this formula: 1 horse per one acre. If you have extreme conditions in terms of climate or altitude, email us and we'll tell you what the formula is in your zone. But for the sake of this article, let's assume that one horse per acre is recommended in terms of grazing practices.

When planning your pasture management you must also take into careful consideration what you are planting as it relates to your region. Your county extension agent is the one to call. He or she already knows which grasses will thrive in your specific region. Overgrazing will mitigate your pasture's tolerance to drought and also allow less desirable forage to develop. Therefore, sectioning off your pasture and rotating your horses to prevent overgrazing is critical to the future balance and productivity of that acreage. Soil moisture levels are also key to determining what will grow in your area. Soil moisture drainage is yet another factor.

So remember these 3 key considerations: horse to acreage formula; planting the appropriate seed for your region; soil moisture content. Again, you have a county extension agent in your community and he or she already has this precise information ready and available to you at no cost.

Confined Feeding Practices


Most horse owners tend to be middle to upper class, educated and informed people. Yet we know little about what goes into our horses' feed. Recently, with the advent of Mad Cow Disease in the United States, the topic of what goes into animal feeds has come closer to the surface. Everyone knows what a rendering plant is. What many people did not know is that some of these animal 'byproducts' were ending up, and still are ending up, in certain domestic animal feeds. From a personal standpoint, I do not want my dogs or horses eating animal byproducts. For herbivores such as cows and horses, this is absurd, and has proven to be quite deadly in a very sinister way. Subsequently, I choose to become more informed about what is in the prepared horse feeds I buy, or I mix my own.

It would be appropriate to suggest a natural diet for the natural horse owner, but what exactly does this mean? A holistic approach to horse maintenance is entirely appropriate and easily achieved. Feeding natural, unprocessed, whole feedstuffs that contain the necessary minerals without unnecessary toxins is the best approach.

A bag of oats or other grains or seeds, for instance, lists the basic mineral content on its label. All the better if it is organic - increased nutrient content, better balanced nutrients, and no toxins.

Hay, roughage - the staple in any confinement diet - comes in many varieties and from many sources. Variety is important to assure a balance of minerals, as is the way the hay was grown. Hay mineral content can easily be analyzed by sending in a sample to your local lab, and the grower can be questioned about how the hay was grown to avoid feeding your horse something potentially toxic (chemical fertilizers, insecticides, and herbicides).

Also, the soil - and grass, for that matter - from your pasture can be analyzed for mineral balance and deficiencies through a lab or your county extension agent.

Basic Minerals:

Calcium is a critical mineral for several of your horse's functions. Heart rate, blood clotting and muscle function are all directly related to calcium intake. Additionally, calcium makes up about 30-35% of your horse's bone structure. Therefore it is critical that there is no deficiency of calcium, especially in the growing years.

Calcium is most prevalent in alfalfa. Alfalfa contains about 1.25% of calcium compared with timothy hay at .43 and oats at only .08% A 1000 pound horse needs approximately 22 grams of calcium per day. This breaks down to 12 pounds of timothy hay or 4 pounds of alfalfa. This is why we choose to feed by weight, not volume. How many of you still measure your horse's feed by flake and by coffee can? I did for many years until that practice was discouraged by Dr. Sara Ralston of Rutgers University Department of Equine Science, whom I consider to be the authority on equine nutrition. Weigh your feed now and then to get an idea of how much you really should be feeding. A younger horse will need as much as 40 grams of calcium and a lactating mare will need as much as 100 grams. This will require some supplementation, as it would not be practical to induce 100 grams of calcium into a lactating mare simply through forage introduction.

Iron is another important mineral to your horse. Fortunately, iron is usually ingested adequately through staple feedstuffs such as hay and grazing, and therefore requires no supplementation. The exception to this rule might be the endurance horse. Typically, iron deficiencies only occur in horses who have had a prolonged exposure to internal parasitic infestation or, in rare cases, significant blood loss. Otherwise, iron is a self-maintaining mineral. In the event of an iron deficiency a veterinarian can introduce iron , which will elevate iron levels to an adequate point within 48 hours.

Phosphorus - Horses require this mineral for the metabolism of carbohydrates, fats and sugars. Phosphorus is also critical to kidney function as well as cell repair. Once again, we look to the 'Natural Horse' method in acquiring this mineral. Phosphorus exists in sufficient amounts in hay and cereal grains. Grasses in their young or early stages of growth contain the most phosphorus. Soil samples can reveal if your pasture or hay sources contain an adequate amount of phosphorus and iron. As a rule of thumb, the average 1000-pound horse will require 14 grams of phosphorus on a daily basis. This amount can be acquired through 9 pounds of oats or 15 pounds of timothy hay. A combination of the two is the obvious approach. One interesting yet little known fact is that horses on pasture can store phosphorus, abundant in the spring and early fall, to make up for later deficiencies in the summer and winter.

Selenium works along with vitamin E to rid your horse of destructive free radicals and aid in muscle development. Selenium is naturally ingested through forage. However, there are certain regional concerns with selenium; some areas have deficiencies, others have excesses. Too much of this mineral can be fatal or cause things such as deformed hooves, increased heart rate, and colic-like symptoms. Not enough selenium can cause immune disorders, reproductive problems, and more. Once again, this is where your County Extension Agent can assist you. Soil testing is quite helpful. In Colorado, I recall selenium toxicity being a real concern, whereas a few states in the west such as California and Oregon, and Pennsylvania in the east, experience a deficiency of selenium in the soil.

Sodium chloride: In other words, salt. This mineral is critical in the regulation of body fluids and the conduction of electrical impulses in the nerves and muscles. This is perhaps one of the few areas where our removal of horses from their natural environment means that we will need to provide this mineral through supplementation. Providing free-choice salt, rocks or loose, is the answer and a horse will ingest the necessary amount of salt through licking it at will. A lack of adequate sodium can also result in a horse's inability to sweat, which is a vital cooling mechanism and elimination function. A horse who is salt-deficient might also experience appetite loss, weakness, and dehydration.

Method of Feeding:

I've seen it all. I managed a large ranch in Colorado many years ago with some 120+ horses on site. My routine consisted of going out at 7:00 AM during the winter and placing 16 bales of hay in the bed of the ranch truck. Then, I would take a piece of baling twine, for which we have all found a thousand uses, and tie the steering wheel to the side view mirror. Placing the truck in first gear I would hop out, jump in the back and throw off flakes. After a half hour I would have a well-spaced line of 120+ horses, about a mile and a half long, eating their hay. This same process was repeated in the evening. What's this you say? I fed on the ground? Yes, it was winter, plenty of snow and no concern for fecal contamination resulting in parasitic infestation. Now in the summer it was an entirely different story. Those same horses were fed in elevated mangers and the removal of fecal matter was paramount to the mitigation of flies as well as parasite issues.

As a rule of thumb, most people own two or three horses. These horses should be fed with several considerations in mind. First, the pecking order. You shouldn't feed two horses next to another who fight. I recall a case of neglect where one horse was remarkably thin and yet the others were all very fit. What was the story here? Simple: All of the horses were fed in one central manger and this particular horse was being run off of the feed by the other horses. Subsequently, he was at the bottom of the pecking order and received the least amount of feed. Take these types of environmental and behavioral issues to heart when arranging your feeding patterns. Take care to make certain your hay is as dust and mold free as possible. Feed off of the ground. On our outfit, we presently place a one-ton bale into an oversized, elevated iron manger. This gives the horses 24-hour access to free choice eating. Several things are accomplished with this arrangement. For example the horse on the bottom of the pecking order can simply walk over and eat to her heart's content when the bullies are finished. Also, they naturally eat when they are hungry so there is less stress and they all winter better.

Assessing the results of feeding:

Measuring your horse's body weight - As a big fan of, and instructor of the Henneke Body Condition Scoring System, I can give some very sound and free advice here. This 1 to 9 number system is an easy to use method and will give you an ongoing idea of your horse's progress or decline. You physically place your hands on your horse in six key areas and write down a score for each area based on the amount of body fat present there. 1 is emaciated (and usually a dead horse). 9 is obese. The ideal horse scores out at a 7 going into winter and a 5.5 to 6 coming out of winter. I have used this method and system as a visual tool for court cases. I have seen a couple of horses during my career that scored overall a 1.5 or less. Those horses died and the scoring method helped the jury better understand how long it takes for a horse to get into that type of critical shape. For use on the ranch, you can measure your horse's progress or decline when using different types of feeding methods. I have a grease board on the wall in the tack room and keep a running tab on all of my horse's scores. It gives me an instant visual aid as to who is doing how well.

There is not enough space in the article to adequately explain this scoring method. I do teach it at seminars and have instructed the majority of the Federal Bureau of Land Management's Post Adoption Compliance Checkers in its use. If you have a club or group interested in learning it first hand, email me for more details.

General appearance - Is your horse shiny, comfortable, energetic, bright? If not, then your feeding and maintenance regimen, and/or your horse, needs input from your holistic veterinarian. Underlying imbalances can thwart the most carefully prepared horsekeeping arrangements, through inabilities to absorb and utilize nutrients, or inabilities to exercise appropriately. These can be holistically addressed.

The natural approach to feeding and nutrition is the best way to care for your horse. When you adopt the natural approach to health and feeding, you more closely mimic the perfect balance that nature originally had in place for horses before our arrival.

Good luck in your endeavors and until next time, enjoy your healthy horses.

About the author:

Kimball Lewis is an Idaho cowboy, lecturer and writer. You can contact him at equestrian2020@aol.com for more information. He is also available for group appearances; he travels throughout the US and Canada conducting seminars.