How to choose the most effective supplements to support your horse
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 to do that consistently, throughout the racing or competition season. Nutrition is a vital part of that. 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, at all? If you conclude that you do, how do you sort the wheat from the chaff and pick the best one?
There are, essentially, only three reasons to feed a supplement:
To improve the balance of the daily ration,
To fill the gap between good daily nutrition and the increased requirements of horses under stress, and
To address specific health concerns.
Daily Ration Balance
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 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 are having to correct deficiencies of energy or protein in your daily feed, consider picking a better-balanced concentrate feed for your particular horses.
In some parts of the world, 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, don’t. With a few exceptions, it’s money wasted. Adding individual nutrients can produce no results or disrupt the balance of a good feed and actually have negative results.
Exceptions to the Rule
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 amount that is toxic), 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, need 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 requirements during times of added stress. If they 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 would need more, absorb it, and use it. That’s money well spent.
At the same time as horses are under extra stress and need more nutrients, they will often go off feed and drink less than usual. Supplements will certainly be helpful, at those times, 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:
Does it have the right stuff? Is it complete?
Is the balance right?
Are the forms of nutrients and the doses going to meet the requirements of your horses?
To help answer these questions, consider the following:
Completeness
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.
Balance
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
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, this is also about the form each nutrient is provided in. 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) is 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 have differences in their bioavailability.
In general, inorganic forms of nutrients are less well used than organic forms, though 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.
Doses and Nutrient Requirements
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's 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.
Addressing Specific Conditions or Concerns
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.
What scientific evidence is there that these products are likely to be effective?
Are the doses provided the same as the doses that produced good results in studies?
If nutritional elements are to be fed, do the amounts meet NRC requirements and are the cofactors needed for their absorption and effect also provided?
What quality, safety, and security assurance does the manufacturer provide?
Quality, Safety, and Security
How do you know if the product you are looking at contains what is 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 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 program, probably represents a company that doesn’t have one.
Feeding supplements can be necessary for adequately supporting horses, particularly during times of 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.
Steps to take in order to prevent respiratory disease after a poor harvest
Article by Alan Creighton (Head of environment and nutrition at the Irish Equine Centre)
I don’t want to sound alarmist because I am generally a very positive person, but I have no doubt that there will be an increase in racehorse respiratory issues this winter and next spring due to a combination of poor hay and straw harvests in conjunction with a very damp autumn.
Through our everyday testing at the Irish Equine Centre we have already seen higher than average fungal contaminated hay, haylage and straw submitted for testing this autumn. Our routine monitoring of racing yard environments in Ireland, the UK and France are also showing increases in fungal contamination in air samples and surface swabs taken throughout the yards. The damp weather conditions from the second week of June right through the summer in western Europe resulted in fields of grass and cereal crops which were showing major signs of fungal contamination while still standing in the field.
It didn’t get much better when the dry spells came in early September. Land was already saturated which meant the crops once mowed were extremely difficult to dry which has resulted in discoloured, dusty, high moisture straw, many hay stacks which heated and oats with high moisture content. Even haylage, which is the normal go to method of preserving forage when conditions are poor has shown much higher levels of contamination thus far. Damp weather in this period also meant that stables themselves were often damp which encouraged fungal growth on the internal surfaces.
Racehorses are athletes that need a fully functioning respiratory system to maximise performance. IAD, COPD, RAO (all forms of equine asthma) and EIPH (bleeding) are respiratory conditions which are major causes of poor performance in racehorses. Fungi and mycotoxins are now recognised as a major cause of these conditions and in particular the pathogenic fungus Aspergillus being the main culprit.
Fungi that penetrate the airways can cause unwanted inflammation and can be infective, toxic, allergenic or all 3 combined. The further the distance a racehorse is asked to race, the more detrimental this inflammation will be to performance. The main sources of this fungus are in hay, haylage, straw and oats.
This fungus is a storage fungus and so it propagates in stored foodstuffs overtime where the moisture level is above 14%. When the fungus contaminates a foodstuff or bedding the horse has no choice but to breathe in the harmful spores in their stable environment. The fungus also causes a level of immunosuppression which can often be the precursor to secondary bacterial and viral disease.
The cost of bedding for racehorses has been steadily rising over the last number of years. Wood shavings have become very expensive to buy but are now also very expensive to dispose of. Straw is still more cost effective to buy and much more cost effective to dispose of.
I will often get asked the question “what is the best bedding for horses?” - my answer is consistently “good straw”. When I get asked the question “what is the worst bedding for horses?” my answer is consistently “bad straw”. The cost saving in purchasing and disposing of straw has made it attractive to trainers in a time when all other costs are rising. Finding good straw this year will be very difficult.
In many countries in Europe, we have a government policy called SIM, the Straw Incorporation Measure which is a payment for chopping straw and incorporating it into the soil. SIM has been designed to encourage tillage farmers to increase soil organic carbon levels by chopping and incorporating straw from cereal crops and oilseed rape.
Unfortunately, an unintended consequence of that policy is the reduction in availability of straw for bedding purposes. This is particularly problematic this year because now we have a shortage of straw and the straw which is available for bedding has much higher levels of harmful moulds due to the poor harvest conditions.
When feeding haylage, the spoilage process can begin quickly if the bale is exposed to air, this may be due to damage of the wrapping or not using the bale quick enough once opened. Fungal spores will develop and this should be carefully assessed before feeding. This is a major problem we encounter on a regular basis. Often trainers are feeding big bales of haylage to a small number of horses which means the bales are exposed to air for a prolonged period of time.
Pathogenic fungi will develop very quickly and often lead to both respiratory and gastric problems. For that reason, the IEC will recommend to use haylage once opened inside of 4 days in the winter and 3 days in the summer. This recommendation will often determine the choice between hay and haylage as you would therefore need to be feeding a larger number of horses to feed large bale haylage.
Hay production requires 7-10 days of continuous good weather unless you are barn drying. In Ireland and the UK we got a two week spell of suitable weather in the last week of May until the end of the first week of June. Many meadows were not ready, and the ones that needed patience from the farmer not to bale too early as hay at that time of the year is very difficult to dry properly due to the lushness of the grass.
Having said all that, the best hay of this season was made in that period. That was the only spell until a two week spell in September. Historically, the best hay in western Europe is made from the middle of June to the end of July. That was not possible this season. The hay made in that early spell is very good in terms of quality but very poor in terms of volume. The hay made in the second spell in September was very high in volume but very poor in terms of quality. The nutrition levels of this September hay is also poor and the fungal levels are very high.
At the Irish Equine centre we analyse thousands of samples of hay, haylage, chaffs, straw and oats every year for both hygiene (mould and bacteria levels) and nutritional content. The reality is that in a normal year with good spells of weather we still get both hay and haylage with extremely good nutritional and hygiene values and we get hay and haylage with very poor nutritional and hygiene values.
This year the percentage of poor is outweighing the percentage of good. Normally we would advise that trainers should produce or purchase enough of the same batch of quality forage for the whole season. That may not be possible this year. It is our experience from testing forage that getting haylage with consistent nutritional values can be very difficult even in a good year. This is mainly due to the variants in moisture content which will certainly be the case this season. Hay which is well made and stored well does tend to be much more consistent and therefore better for overall horse health.
Both hay and haylage are prone to fungal contamination in different ways. With haylage the fungal contamination occurs as a result of inadequate fermentation or when air pockets or punctures occur in the plastic.
Fungal problems in hay occur because of high moisture levels during the baling process and because of inadequate storage during winter months. We have shown in the past that those fungal problems are compounded and elevated since farmers have moved away from the traditional small bale and moved to large round and rectangular bales. Farmers who traditionally barn dry small square bales, who ensure that hay is dried below 14% moisture and then covered (a layer of clean bales of straw) in storage remains the most hygienic hay for racehorses.
During storage the moisture level on the outside of uncovered bales significantly increases over damp winter months, leading to a significant increase in fungal growth. Round bales suffer the worst during storage. Hay in large bales needs to have a very low moisture level when baling, which just wasn’t possible in most cases this year when field drying.
When this type of bale has a high moisture level in the centre of the bale it results in significant increases of pathogenic fungi contamination during storage. We have shown through studies that keeping the moisture level of hay below 14% moisture will significantly reduce Aspergillus contamination. It was very difficult to achieve this moisture reduction this summer and often farmers had no choice but to treat the hay with buffered propionic acid which is an effective preservation method which reduces fungal growth during the early stages of storage but its effect diminishes over time.
Good quality tested hay is still the most beneficial to horses when all factors are taken into account. Once purchased hay should be stored properly by the supplier to ensure that it remains consistent. The hay supplier should ideally guarantee the trainer a supply of hay which is consistent for the whole season rather than swapping and changing batches constantly.
All hay should be covered from the end of September once the moisture content has stabilised to protect it from damp air during winter months. Trainers with inadequate storage may have no choice than to feed haylage. If this is the case, buy the right size of bales for the amount of horses you are feeding.
Steaming of hay in the correct manner can be a very useful process to reduce the fungal load in contaminated hay. Some producers of hay harvested very early this year to take advantage of that good weather spell. First crop hay when harvested early can be difficult to save and can have a very high protein content. That high protein is good if you test it to quantify the actual protein content and you then balance your feeds accordingly.
If high protein hay or haylage is used and feeds are not adjusted accordingly it can overload the digestive system with nitrogen. Excess of protein will also lead to an over production of urea, leading to an excess of ammonia emissions in the stable which can also cause respiratory irritation.
So, what is the advice from the IEC? Trainers will need to test their hay and haylage at multiple stages during their season as the dangerous fungi will develop over time. The volume of suitable forage and bedding will be low, so trainers should act quickly to secure the best that’s available.
The nutrition department at the IEC provides full nutritional and hygiene testing for hay, haylage, straw and oats. It is vital that you test forage pre-purchase when trying to buy a season's supply. Hay, haylage or bedding contaminated with pathogenic fungi will cause respiratory disease which will affect racehorse performance.
For that reason, the cost of testing forage is a small price to pay rather than losing significant portions of the season due to poor performance as a result of respiratory disease. How you store and feed hay, haylage, and oats will have a huge impact on the level of exposure your animals will have to harmful moulds. Stable hygiene and ventilation will be even more critically important when the risk of contaminated inputs is so high.
To conclude, trainers should always acquire the best possible forage and bedding available and test it prior to purchase. You can and should inspect and test any batch of hay or bedding properly prior to delivery. You can take a representative sample for the testing lab which can then be the deciding factor for your purchase. When taking a sample, take a fistful from 6-8 different bales in the stack to ensure you get a representative sample.
We monitor the stable environments of over 200 racing yards in Ireland, the UK, France and in the Middle East. That monitoring includes hygiene sampling of feed, forage, bedding, water, stable surfaces, walker surfaces and air quality in barns. The benefits of that monitoring for the trainer is that you highlight issues which can cause respiratory disease, proactively prevent disease problems and finally have a mechanism which quantifies the effectiveness of stable disinfection routines.
The most consistent trainers in terms of performance have good hygiene practices. If anybody would like to discuss the above issues or need help with assessing the quality of forage and bedding in use, please contact myself or any of my team at nutrition@irishequinecentre.ie and we would be glad to help.