Supplementing the equine diet
By Kate Hore RNutr(Animal), senior nutritionist with NAF
Any bucket feeds should also be based on short chop fibre and split between multiple feed times to mimic grazing.
Horses and ponies evolved as trickle grazers which means, as most of us know, they love to eat all the time!
Around 16 to 18 hours grazing per day is normal for horses allowed free access to pasture. This habit of eating for hours isn’t greediness, but a natural adaptation which allows horses to effectively digest tough, fibrous plants, and extract their required energy, fibre and nutrients from that.
As horse owners, and advisors, this means that if we want to keep our horses and ponies happy and healthy we should be basing their diet predominantly on forage, ie. grazing, hay or haylage.
Natural diets, high in fibre and low in starch, have been shown to improve behaviour and reduce the risk of a number of common health issues such as Equine Gastric Ulcer Syndrome (EGUS) and laminitis. Ideally, any bucket feeds should also be based on short chop fibre and split between multiple feed times to mimic grazing.
Balancing the diet
The only real issue with this natural diet is that it can be lacking in nutrients required for health and vitality, particularly the micronutrients – vitamins, minerals and trace elements. It’s a fair question to ask - why, if it’s so natural, is the forage diet not meeting our horses’ dietary requirements?
There are a number of reasons as to why this might be. Firstly, grazing for the modern horse lacks the variety of the shrubs, herbs, legumes and trees available to natural horses. Studies have shown wild horses graze a huge number of species, and will even select different herbs and grazing dependent on the time of year.
Conversely, modern grazing usually only contains one or two species of grass and, perhaps, a legume. So it’s important to put back some of the variety in the diet. Secondly, areas of soil deficiency for certain nutrients are common in the UK. This deficiency will be passed to the grazing and also to the forage harvested in that area. Therefore, again, it’s important to balance up those deficiencies. This is where supplements are advised.
Broad spectrum supplements contain the required vitamins, minerals and trace elements, and are available as powders, liquids or pellets; the choice of which is usually personal preference.
A good quality product will be designed to balance what is naturally provided in a high fibre diet, rather than, for example, providing 100% of RDI (Recommended Daily Intake) for all nutrients - which rather implies the horse shouldn’t eat anything else at all!
Remember, over-supplying just means the horse works harder to excrete excesses, or runs the risk of stores building within the system. So look for a balancing product to suit that horse, their age, work load and body condition score.
For working equines, and where maintaining condition is important, supplements will usually include gut support. The harder the horse works, the harder the gut works – and keeping the gut happy and healthy is the secret to keeping the horse happy and healthy.
That gut support may be live probiotic yeast, such as Saccharomyces cerevisiae for the hind-gut microflora; prebiotic sugars, which support the role of the probiotics; natural antacids, such as calcium carbonate, or herbal gut support from plants including mint, ginger and psyllium.
Brewer’s Yeast is also commonly included and is an inactive form of Saccharomyces cerevisiae, meaning the yeast is killed off so doesn’t have a probiotic action, but it’s a useful source of B vitamins, and is considered to support gut health as a prebiotic.
Both probiotic yeast and brewer’s yeast commonly appear together in products, and can cause confusion when reading the label, so it’s worth understanding the difference.
The live probiotic will be listed as Saccharomyces cerevisiae in the Additives section of the label, and will have a ‘cfu’ (colony forming unit) figure telling you the inclusion rate of the yeast. Brewer’s yeast may be listed as ‘Saccharomyces cerevisiae (inactive)’ and will be under Composition, as it’s classed as a feed material rather than additive. This explains how ‘Saccharomyces cerevisiae’ may appear twice on a label from very different ingredients.
The final combination of gut support used in a product will depend both on the manufacturer, and the type of horse the product is designed for.
Feed balancers, which are concentrated, nutrient rich feeds typically fed at between 100g – 500g per day, are really just an extension of this. Balancers usually include gut support alongside vitamins and minerals for health and vitality, so are a form of broad spectrum supplement, generally fed as pellets.
Once the diet is balanced, supplements can then be considered which go beyond simply diet balancing to target various areas of health specifically. The term ‘nutraceutical’ is a fairly new one, but simply means using nutrition as a therapy tool.
This is nothing new, herbal veterinary formulae can be found recorded in the pyramids of ancient Egypt. And increasingly, ‘old wives tales’ are being validated through scientific research.
We all know the power of plants, whether we think we do or not. For example, would you casually chew on some deadly nightshade, or let your horse graze ragwort? So if we know certain plants can be powerfully harmful, it’s not a big leap to understand that others can be powerfully beneficial.
The science of supplements is putting the right combination of those plants and natural ingredients together to support health. Nutraceutical supplements can cover all areas from a simple biotin and zinc blend for hooves, through technical combinations of glycosaminoglycans (GAGs) for joint health, to innovative herbal antioxidant complexes to flush out oxidative stress.
All supplements are legally classed as complementary feed and, as such, come under EU feed law, which prevents any medical claims being made.
While this is a good thing in preventing unsubstantiated claims, it does mean manufacturers are restricted in how they market their supplements, particularly for the targeted nutraceuticals. So if you’re unclear as to whether a supplement is appropriate for a particular horse or not, discuss it with the manufacturer who should be happy to advise.
In conclusion, supplements can basically be split into two groups – those designed to balance the diet, whether covering deficiencies or replacing what has been lost through work, and those designed to be used in a targeted way for specific health support.
What do horses eat?
Nutrition plays a significant role in equine health and welfare, so it’s difficult not to discuss feeding within any healthcare conversation. For SQPs, therefore, a working knowledge of nutrition means a better service to clients, says Ruth Bishop.
The dietary options on offer in any store are many and varied. No wonder the choice of product can sometimes be quite overwhelming for consumers.
The spectrum of feedstuffs is very wide, with intake ranging from many kilos per day to a few grammes. The major categories are as follows -
Of course there’s some blurring of the edges between categories as some products sit between two, for instance mixes containing high proportions of fibre.
Horses mainly eat forage, in the form of grass, hay or haylage; forages are what horses are designed to eat, and are essential for a healthy horse. Forage is capable of supplying the energy, fibre and protein needs of a horse, especially one at maintenance or light work – although essential micronutrients will in many cases need topping up.
At least 50% of the daily diet should be forage, but in most horses it is significantly greater than this – typically over 80% of the daily diet in many horses kept for leisure purposes.
Good pasture contains an even cover of palatable grasses, free from weeds, and provides a rich source of nutrients from energy and protein to vitamins, minerals and plant phytochemicals.
Horses thrive at grass - physically and mentally – but some do too well, gaining excess weight. A recent survey of predominately outdoor living horses found that over 30% were overweight.
The amount of nutrition that grass provides varies according to the time of year, the grazing management, the number of horses (or other animals) grazing the land and how long the horse is turned out for.
Good grass is generally equivalent to a medium or high energy, high protein feed. It’s at its very richest in spring (and often again in the autumn), when the protein content can be above 20% and the energy content equivalent to that of a racing feed. Actively growing grass can be rich in sugar – as much as 3% of every mouthful, and this together with fructans, a storage form of plant sugar, has been implicated in the incidence of pasture-associated laminitis.
Poor grazing isn’t as rich, but a horse turned out for several hours a day can still easily receive more from its pasture than it will from most low energy feeds.
Hay is dried mature grass, normally in the form of either:
• Seed hay - usually perennial ryegrass varieties, timothy or specialist blends of them, grown and sown specially for hay. Seed hay tends to be quite coarse in nature with a relatively low energy and protein content; or
• Meadow hay - from pasture permanently kept as grass, usually comprised of a more varied mixture of grass species, and tends to be softer and finer with a higher nutritive value than seed hay.
As a general rule of thumb, small bales weigh about 20kg, with large bales weighing 250-350kg depending on size. A slice or section from a small bale typically weighs about 2kg / 4lbs.
The main concern with hay is its hygienic quality: moulds, spores and other dust particles that develop during harvest or storage can cause respiratory irritation and lead to the development of Recurrent Airway Obstruction (RAO) in horses.
Soaking and steaming Hay
Unless it’s been expertly dried in controlled conditions (there are suppliers who do this), UK hay is likely to contain some mould and dust. Soaking or steaming hay are popular ways of removing any dust, by either removing the particles, or effectively ‘sticking’ them to the grass stalks so that they are consumed rather than inhaled.
Research has shown that 30 minutes’ soaking is effective. Soaking hay also causes some loss of nutritional value as some soluble sugars and proteins are leached out into the water; more soaking equals less nutritional worth. Owners of laminitis-risk horses can take advantage of this to reduce unwanted sugar contents.
Haylage is grass that is baled moist (typically 35-40% moisture) and then bagged or wrapped to keep the air out and moulds from forming. It’s popular with growers because it’s easier to make than hay, and with horse owners because of its low dust and spore content. Plastic packaging means it can be stored outside.
Disadvantages are that quality can be variable between different suppliers. Also portioning can be a challenge, since the bales don’t often break into easy slices. Moisture content can be variable between suppliers, ranging from 20-50%.
Small haylage bales weigh about 25kg, whereas large wrapped bales can be 180-250kg or greater.
Haylage tips for SQPs
• Up to 50% of haylage can be water, compared with 15% in hay, so it cannot be fed on a weight-for-weight basis with hay; advise feeding about 1½ times the weight of haylage as hay.
• The quality of the airtight seal is essential. Air ingress will allow mould growth in the bales. Small bales may split at the seal, large bales can be punctured by haylage stalks or from bird, rodent or mole damage.
• Quality is all important, so choose a supplier with a good reputation and ask for an analysis of their product.
• A good rule of thumb is to use a bale within four days of opening (less in summer) as moulds start to grow again immediately the bale is opened.
• Avoid feeding visibly mouldy haylage and “gritty” or soil contaminated material, as there could be a risk of listeriosis.
Hay and haylage are often thought of as an inert and safe nutritional bases. However because they constitute such a large part of the diet their contribution is worth monitoring especially if the horse competes, is at risk of laminitis, has Cushings disease etc. Energy, protein and sugar contents can vary depending on the grass species, date of cutting and the weather during cutting and baling. Sugar contents can exceed 10% in some forages. Nutritional value can be quantified by a simple test, a service offered by many feed manufacturers.
Ad lib forage feeding
Many owners feed on a free access or ad libitum basis to ensure the horse always has forage available. Actual individual amounts consumed should be monitored though as offering ad lib doesn’t always mean an optimum intake especially where several horses share the forage, or if the quality is variable.
Chaffs and forage replacers
A number of chopped fibre products are marketed as forage replacers. Chops and chaffs that can be added to the hard feed to bulk it up or slow down the rate of eating. There is some evidence to show that horses take longer to eat short chop forages than they do hay or haylage.
There are also complete fibre feeds available fortified with protein, vitamins and minerals etc., designed as the full compound feed. These aim to fit more closely with the digestive physiology of the horse, and are particularly good for horses or ponies prone to laminitis and digestive issues such as gastric ulcers.
Compounds are balanced blends of ingredients formulated to meet the requirements of horses when fed in conjunction with forage. A recent survey found 87% of owners feed some form of compound, the majority of which was commercially prepared.
The market for compound feed is highly fragmented with different products and product forms for every kind of horse or pony (see table below). Balancers are concentrated, nutrient-rich versions of compounds, and the balancer category has itself recently become more fragmented along similar lines to compound feeds.
energy / High fibre
|Cubes and mixes with a high fibre content designed for horses at maintenance, in light work, or for horses that work well off low energy feeds.
||1-4 kg per day
|Cubes and mixes with additional nutrients for older horses. Some come in low-and high-energy form; some
contain joint support ingredients.
|1-4 kg per day
|Usually in fibre-mix or cube form, low energy, high fibre, low starch and sugar complete feeds.,Capable of replacing the total diet of at risk animals.
||1-10 kg per day
|Medium energy cubes and mixes with higher vitamin and mineral contents designed for the working and competing horse or pony.
||2-6 kg per day
|Higher energy and protein feeds designed to put on weight. Some are starch based, but more modern
versions are high in fibre and oil to ensure condition is achieved without increased excitability.
|1-3kg per day
and breeding feeds
|High energy, protein and mineral feeds designed for breeding stock.
||2-6 kg per day
|High energy cubes and mixes for horses in training or intense work.,Traditional products are starch based, but
modern variants use alternative energy sources such as oil and digestible fibre to support digestive health and aid performance.Some companies offer low energy lay off or rest and recuperation variants for horses on the easy list.
|5-7 kg per day
nutrient-rich pellets, supplying essential amino acids, vitamins and
minerals.,Commonly marketed to
complement high-forage diets, but also as top-ups to existing diets or when
cereals, eg. oats, form a large part of the diet.
Supplements augment the nutrition provided by the main part of the diet. They come in a variety of forms; powders, herb blends, liquids, pastes, pellets, licks - and in a variety of packaging.
Under regulations governing animal feed, supplements are considered “complementary compound feeds” as are cubes, mixes and balancers. However in the horse owner’s eyes, they fulfil a different role, tailoring individual diets to meet specific needs.
Supplements are used regularly, with estimates of their use in 80% of equine diets.
There are two main categories of supplements:
- Broad-spectrum: providing a broad spectrum of major and trace minerals together with vitamins, these are designed for topping up micronutrient levels where little or no hard feed is fed. There’s some blurring of the edges here between balancers and broad spectrum supplements in terms of the nutrients they supply. Balancers tend to be in pelleted form whereas supplements can be in the form of a powder or a lick.
- Specific: providing an ingredient or mixture of ingredients designed to perform a specific function. These range from daily addition of salt and/or oil to the diet to more targeted support, eg. for joints or hooves.
The top five specific nutritional concerns of horse owners are hoof quality, joint quality, colic, care of the senior horse and laminitis. Behaviour also ranks highly especially related to supplement purchases. Different companies takes different approaches to each functional area, and the following table gives some examples of these.
Medicinal claims for supplements and feeds are not permitted. There is an exception for laminitis, but only in relation to a product’s (low) starch and sugar content. Claims linking laminitis and hoof health are not permitted.
||Examples of typical product approaches
||- Nutrients and herbs associated with calming or modifying behaviour eg.magnesium
Probiotics – in case behaviour is caused by digestive discomfort
||- Support to the cartilage via providing building blocks for cartilage formation
e.g. glucosamine, chondroitin sulphate, MSM, collagen
- Increased antioxidant support to combat free radicals in the joint
- Substances added to support joint comfort
||- Nutrients to support hoof growth and development
- Biotin is research proven but other vitamins, amino acids and trace
elements can also be added.
|Skin and coat
||- Oils, particularly sources of omega 3 fatty acids
- Nutrients and herbs that help coat and skin quality
About the author
Ruth Bishop is a director Ruth Bishop Consulting Ltd. She has 25 years’ research and development experience in animal nutrition both in consultancy and commercial roles in major food businesses including Dalgety and Mars. She is a former technical director of Mars Horsecare and works with feed industry trade associations.