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| Staff Writer |
Good horse people want to do the right thing for the horses in their care. They want to help them perform to the best of their ability, and they want to help them do that consistently throughout the racing or competition season. Nutrition is a vital part of performance. Every season, stables are presented with a long list of supplements, and every rep says theirs is the best. How do you know if you need to spend money on supplements? If you conclude that you do, how do you sort the wheat from the chaff and pick the best ones?
There are, essentially, only three reasons to feed a supplement:
1. To improve the balance of the daily ration,
2. To fill the gap between good daily nutrition and the increased requirements of horses under stress, and
3. To address specific health concerns.
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First, remember that horses’ guts have adapted to digest roughage, and they need it. Hay (or grass, if you are lucky enough to have it) is the basis of a good daily ration.
You only need to feed a concentrated feed (the stuff you buy in a bag, like a racehorse or a stud farm mix) to meet the additional protein, energy, vitamin, and mineral requirements that horses in work, growing, or breeding have. If the concentrate feed you choose has been prepared by a major feed company, it will generally be balanced for those things already, and they will essentially meet the daily needs of horses, when fed with forage. If you have to correct deficiencies of energy or protein in your daily feed, consider picking a better-balanced concentrate feed for your particular horses.
In the Middle East, grass isn’t plentiful, so forage is generally fed in the form of hay or green feed. Depending on the type of hay you choose, calcium and phosphorus balance might have to be adjusted with a daily supplement. You should ask your nutritionist or veterinarian to help you to get that right. In general, though, grains are high in phosphorus and low in calcium. Lucerne (Alfalfa) is high in calcium, while grass hays are generally lower in it. Feeding a mixture of grass, hay and Lucerne as the main part of your daily ration will likely mean that calcium and phosphorus will be close to right in your total ration, including the right concentrated feed. As an added bonus, Lucerne is a very good source of cost-effective and bioavailable protein for horses.
If you don’t need to add other stuff to your daily ration, then don’t. With a few exceptions, it’s money wasted. Adding individual nutrients can produce no results, disrupt the balance of a good feed, and actually have negative results.
If the daily ration has selenium provided in an inorganic form, such as sodium selenite or selenate, have your veterinarian check blood selenium. Some horses will absorb and use those forms of selenium well, and others might not. Selenium has a very narrow therapeutic range (the amount they need is only a little bit less than the toxic amount), so it’s dangerous to over-supplement. If some horses need more, pick a supplement that provides selenium in an organic form, like selenomethionine or selenocysteine. Yeast-based selenium is mostly a mixture of the two.
In a hot climate, some additional table salt or a salt block will be needed. Every horse, even spelling ponies, needs access to a salt block.
Stabled horses and those in the Middle East don’t always get much grass. If horses aren’t getting fresh, growing grass, vitamin C might be low. Although it is often included in prepared feeds, it can be unstable, especially in hot climates, and levels can quickly drop. You might consider supplementing with vitamin C when horses are under extra stress. Vitamin C and the B group vitamins are water-soluble, and they are not stored in the body. As a result, it makes more sense to provide those in supplements, given only when horses are under extra stress and requirements are increased.
When horses are under the added stress of hard work, transport, racing, competition, high heat and humidity, or ill health, requirements for many nutrients are increased. Feeding a daily ration designed for horses in hard work will generally provide energy, protein, fat-soluble vitamins, and mineral levels to meet their overall needs, but some nutrient requirements will be increased beyond that, just at the time horses are under stress. B vitamins, for instance, will be needed in doses between 20 and 200 times the requirements during times of added stress. If horses were fed doses at this level on a daily basis, much of the dose would pass out in the urine. That is money wasted. On days they are travelling, racing, or sick, they will need more, and they will absorb and use it. That is money well spent.
When horses are under extra stress and need more nutrients, they often go off feed and drink less than usual. At these times, supplements will certainly be helpful to fill the gap between good daily nutrition and the amount of nutrients they are eating and drinking voluntarily.
When you need a supplement for times of increased stress, it’s really important to read labels carefully. Ask yourself these questions:
1. Does it have the right stuff? Is it complete?
2. Is the balance right?
3. Are the forms of nutrients and the doses going to meet the requirements of your horses?
To help answer these questions, consider the following:
Metabolism is complex, requiring a broad range of essential nutrients. You can’t just feed two or three of them and hope to support performance, recovery, health, and metabolism. A lot of one nutrient doesn’t make up for deficiencies in another. If you ran out of food in your house and tried to just live on a big bag of salt, you wouldn’t last long. It is, therefore, important to consider if the supplement you are evaluating is complete enough to meet the complex requirements of equine physiology.
The balance between nutrients is equally important. Some nutrients are required for the uptake and function of other nutrients. (These supportive and cooperative nutrients are called co-factors.) Too much or too little of one nutrient may result in deficiencies or toxicities of other nutrients. Imbalances, therefore, can have a negative impact on health, performance, and recovery. At a minimum, imbalances in a feed or supplement can cost you money and have no effect at all.
For example, vitamin C is required for the absorption of iron from the gut. Without it, iron passes straight through the gut and out in the manure. Vitamin E binds with iron and reduces its absorption, causing much of it to be wasted. So, for horses to use dietary iron effectively, it has to be given with vitamin C and without vitamin E.
Bioavailability refers to how well nutrients are absorbed and used. While this is partly related to the composition and balance of nutrients in a product, it is also about the form in which each nutrient is provided. Some forms are more easily absorbed and used by the body than others.
The trace element chromium, for example, exists in several different forms. The form of chromium found in a chrome bumper on a car is, as you can imagine, not very digestible at all. The more organic forms like chromium picolinate (for people) or those incorporated into yeasts (a form often found in daily feed supplements for horses) are very easily absorbed and then used by cells. Minerals, including calcium, magnesium, iron, cobalt, copper, zinc, selenium, and manganese, can all be provided in a variety of forms, each of which has differences in their bioavailability.
Generally, inorganic nutrients are less well used than organic forms. However, that is not always a reliable rule. Zinc oxide is one of the more bioavailable forms of zinc, whereas zinc chelate forms a big molecule that can be too big to be well-absorbed. In most cases, though, minerals provided as gluconates, lactates, and amino acid or protein complexes are well used.
When reading labels, you should note whether the amount of the ingredient or the amount of the active nutrient is listed. For instance, Iron Bioplex, in which iron is bound to amino acids, contains only about 10% iron. If a label says a product contains 400mg of iron per dose, that means that a dose contains about 4000mg of Iron Bioplex, yielding 400mg of very well-absorbed and used iron. If the label says a product contains 400mg of Iron Bioplex per dose, then it really only has 40mg of actual iron. Make sure that you check those details carefully when reading labels and comparing products.
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Do the doses of nutrients meet science-backed nutrient requirements? Caution! This might require math before you can measure a supplement against published nutrient requirements.
Labels will include the quantity of each nutrient, but those might be listed per kilogram or per dose. They might be in milligrams (mg), grams (g), or kilograms (kg), pounds (lb), ounces (oz), parts per million (ppm), percentages, or, in some cases, a combination of units. All of these must be converted to the same units as the published nutrient requirements, and all have to be calculated per dose. It sounds seriously confusing, and it can be, but it’s also vitally important. If math isn’t your thing, ask a nutritionist for help. You can look up “NRC requirements” yourself or ask your nutritionist or veterinarian for help with this, too. Many feed companies have in-house nutritionists, and this can be a good way to get help for a minimal charge or even for free if you don’t have your own nutritionist.
Here is a tip to help make things easier:
If labels are easy to understand, and you can tell, at a glance, what you are feeding your horse in a single dose, then the manufacturer probably believes their formulation will stand up to scrutiny. If you have to perform too many calculations to figure out what you are giving, there’s a fair chance that the formulation isn’t great.
In any case, take the time to do the math and make sure you are comparing apples to apples before picking a supplement to spend your money on.
Once the ration is properly balanced and nutritional requirements are being met effectively, you might also wish to feed supplements designed to address specific health issues. Nutraceuticals fed for healthy joints and tendons or as digestive aids are common examples, and nutritional elements (vitamins, minerals, and amino acids) are also marketed for specific concerns. For example, vitamin K1 may support the development of strong cannon bones; biotin is fed to horses on high grain diets to support healthy hooves; chromium is fed to support muscle cells; and a variety of nutrients are fed to relax highly strung horses or to support red blood cell production in anaemic horses.
If you are looking at extra supplements like these, there are a few important questions to ask.
1. What scientific evidence is there that these products are likely to be effective?
2. Are the doses provided the same as the doses that produced good results in studies?
3. If nutritional elements are to be fed, do the amounts meet NRC requirements? Are the co-factors needed for their absorption and effect also provided?
4. What quality, safety, and security assurance does the manufacturer provide?
How do you know if the product you are looking at contains what it says it does, only a fraction of what it says it has, or way more than it is supposed to have? Even more alarmingly, how do you know it doesn’t contain contaminants that aren’t supposed to be there?
There was an interesting study presented at an American Associate of Equine Practitioners (AAEP) meeting several years ago, in which several nutraceuticals were tested, and their actual contents were compared with label claims. Those products were found to contain anywhere between 10 and 200% of the active ingredients that they were supposed to have. That is potentially a huge problem! If a product has too little of an ingredient, it may not be effective and will be a waste of money, but if it has a lot more than it is supposed to have, it may make horses sick or return a positive drug test result. We have already talked about how only a little too much selenium can be toxic, but for some nutrients like cobalt, an essential trace mineral, feeding too much will produce a positive drug test. Contamination of feed supplements with Naturally Occurring Prohibited Substances, like caffeine, can also produce a positive test.
So, how do you know if a product is manufactured safely and meets its label claims?
This information isn’t generally on the label, but it can be just as important as the label itself. To get it, you either have to know the company management personally and have confidence in their diligence and ethics; you might have to talk to the manufacturer and ask questions; you can look at their website to find a statement about quality management; or you can look for third-party certification of their quality management practices. GMP or ISO certification are good ones to watch for. If a company has either ISO or GMP certification, you can be sure that the supplements they produce will be safe, secure, and generally meet label claims.
If a manufacturer lacks certification, it doesn’t mean they aren’t doing a fabulous job of quality management. They might have a written statement about their commitment to quality management, or you might have to ask some questions to be sure. If at least some proportion of the finished product undergoes analysis for common contaminants, the concentration of active ingredients, and microbial testing, it will likely be safe. If no testing is done, and the company doesn’t talk about product quality, safety, and security, you should be concerned.
Tip: Be sure to ask every rep that visits your stable about quality management, as they will almost certainly be the most readily available source for this information. That is also a simple way to separate the wheat from the chaff. Any rep that can’t talk competently about their company’s quality management programme probably represents a company that doesn’t have one.
Feeding supplements can be necessary to adequately support horses, particularly during hard training, racing, competition, transport, illness, or stress. It is your responsibility to ensure the supplements you are feeding are necessary, complete, balanced, bioavailable, effective, and safe for health and drug testing. Get good value for money by avoiding under or over-supplementing. Hopefully I have helped you to make good choices, but remember, if in doubt – seek further advice from an equine nutritionist, veterinarian, or feed manufacturer.
Corinne Hills, DVM. Dr. Hills is a retired equine veterinarian with a general interest in equine nutrition. For 25 years in practice, she mainly focused on poor performance in racehorses, but she also worked on horses competing in endurance, equestrian sports, polo, and polocrosse. She believes that optimising nutrition, health, and soundness is the most efficient way to ensure that elite equine athletes can maintain consistent, top-level performance, and she believes that educating horse people is the best way to help them achieve that for horses under their management. Dr. Hills and her husband own Pro-Dosa International Ltd.