Equine Nutrition

With any horse or human, for that matter, nutrition is an essential consideration when it comes to health management. It can be difficult for owners of horses to navigate the wide variety of opinions and advice on offer and this could potentially lead to horses receiving the wrong diet for their unique constitution.

Here my aim is to inform on the general principles of nutrition and investigate the current evidence. As with all advice and information found within articles, it is important to remember this is only generalised information and owners should always seek veterinary advice before making dietary changes for their animal. 

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What is Nutrition? 

Nutrition as a science is deep and practitioners study to degree level to practice and will further specialise in various areas of the science. In as plain a description as possible, nutrition is the combination of food, water, and supplementation to provide the living being with the essential reserves needed for healthy functioning. 

Nutritionists will assess the unique case of each horse and address the various potential deficiencies with tailored plans and supplements. Nutrition is not just about the actual type and content of food being provided but also the timing and amount. 

Domesticated horses will have a different diet to those in the wild. Wild equines will graze and browse on a variety of plant material and succulent forages containing proteins, water, lipids, and carbohydrates but much less starches than our domesticated horses (Frape, 2010). 

While many will try to create as natural an intake of food as possible, the reality is that without hundreds of acres of land that is biodiverse and flourishing, this is not possible. The science of nutrition allows for the creation of foodstuffs that best provide the horse with the fuel, vitamins, and minerals that they have evolved to consume but with the convenience and availability that domestication necessitates. 

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The Essentials of Equine Nutrition

So what do horses actually need in their diet? Horses are known as trickle feeders in that they eat at frequent intervals throughout the day. We do tend to provide horses with bulk meals at various times too but these will depend highly on the individual needs such as their activity, age, and health status. 

The most important principle in equine nutrition is that they must have access to water and some kind of forage the majority of the time. Of course, at times the horse may, by participating actively in exercise and sports, would not be eating. There will also be occasions where food should be removed for the horse’s health and safety such as when recovering from anesthesia or sedation due to the risk of choking. 

Secondly, the horse must receive the correct balance of macronutrients for their unique constitution. This means that there should be an adequate intake of proteins, carbohydrates, lipids, and fibre. The amounts will vary depending on the individual's demands (Geor, Harris and Coenen, 2012). 

Timing of the feeding is also important. When offering forage such as hay, haylage, and grass, eating is generally continuous in most cases and horses will self-regulate their intake when the forage is available. 

However, when feeding hard feeds such as mixes, pellets, and soaked feed, they need to be spaced appropriately throughout the day. We must also consider that horses will naturally eat less during the night due to the fact they are diurnal (Melyni Worth, 2010). The horse’s digestive system can get overloaded with the high concentrate feeds and this can lead to problems such as colic. 

The quality of food and supplements is vital. Due to the type of feeds we provide domesticated horses, it is not uncommon to find problems with storage or pests that have caused feed quality to be compromised. 

Hay and other forage if not stored well can become wet leading to mold growth. Hard feeds should be stored where pests such as mice and rats cannot access them. Water should be clean and free of potential parasitic organisms. 

We should also consider the quality of grazing. This can be through good grassland management and seasonal rotation, clearing droppings from fields to avoid increased parasite burdens, and removing toxic plants from fields such as ragwort or acorns. Finding a good feed supplier will often negate problems with quality. 

Individuality is fundamental to nutrition study. Each animal will have their own intrinsic and extrinsic factors that affect the behaviour around eating, physical ability to digest and absorb, and of course different physical activity demands. 

Horses in older age will often develop dental issues as a result of the natural eruption of their teeth and eventual loss of them. This will inhibit their ability to masticate (chew) longer forage such as hay and will necessitate forage replacement meals high in fibre. 

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Equine Macronutrients & Micronutrients 

To understand the way in which feeds affect our horses, we need to understand the components that makeup food. Macronutrients are the components that bodies need in larger quantities in order to create and store energy and repair. 

These are the fats, proteins, carbohydrates, fibre, and water we provide in a variety of foods and forage. These compounds are made up of smaller components and are broken down into those components in digestion to be used or stored. 

Micronutrients are the vitamins and minerals that we need in smaller quantities but are essential for healthy functioning. These include B vitamins, Fat-soluble vitamins A, D, E, and K, minerals such as zinc, iron, and magnesium, and many others. 

Micronutrients are essential in processes such as facilitating the production of DNA, producing enzymes and hormones, and allowing nerve function. The body can synthesise some of these but some are known as “essential” meaning that the body needs to gain them through nutrition and supplementation. 

It can help to understand the uses if you think of the macronutrients as the body's raw materials and the micronutrients as the many tools and helpers that allow us to utilise them. The ratios of different macronutrients and micronutrients are important to consider when feeding and even in an otherwise healthy animal, a continuous lack of a certain nutrient can lead to deficiency and symptoms will become apparent. 

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Variations in Horse Nutrition Requirements 

A horse’s requirements for certain nutrients will vary depending on their age, health status, activity/sports, pregnancy, and even behaviour. In early life, the horse will be dedicating a lot of vital resources to growth and development, this will necessitate a higher proportion of protein in their diet than their adult counterparts. 

For similar reasons, a lactating or pregnant mare will also need higher protein feed. Excessive sweating can seriously deplete electrolytes such as sodium and potassium (micronutrients) which play essential roles in fluid transfer and nerve conduction and so these may need to be increased in horses with heavier workloads or at certain times of the year. 

Many horse owners will increase the intake of fats in their horse’s feed during the winter months. This can be very useful to ensure they have the reserves to self-regulate their temperature in the cold. However, it can be tricky if the horse gains too much weight and owners need to be aware of any conditions such as equine metabolic syndrome (similar to diabetes in humans) or laminitis and how these affect or are affected by weight gain. 

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Types of Hores Feeds

It can be overwhelming at first when looking at all the available feeds and forage types as a horse owner. The key is to get some clear and educated information from a nutritionist and the feed producers. 

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Forages

These are the high-fibre feeds that are lower in starches and provide the horse with the bulk of their diet. Horses have evolved to feed little and often so this type of food is essential. 

Hay and haylage provide them with plenty of chewing. Horses can chew up to 18 hours of the day and if they do not have sufficient forage to chew on, this can cause stress by stopping them from performing natural chewing behaviour. 

The slower breakdown of fibre in the hindgut also helps horses to regulate their temperature as this breakdown creates heat. Regular adequate access to forage also protects the horse from gastric ulceration by the continual flow of food and saliva into the digestive system. 

Horses are continuously producing stomach acid and saliva acts as a pH buffer to reduce the risk of ulceration. This should be the largest component of the horse's diet. Soaked feeds such as sugar beet also provide extra fibre at times of the year when sufficient grass may not be available. Feed companies also create high fibre hard feeds in pellet and mix form. 

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Concentrates

These are what some people refer to as “hard feed” or “grain”. These are cereal based foods derived from oats, barley, and maize. Concentrates are much more energy-dense than forage and are very useful for providing the additional macronutrients a horse may need if they are in work, aging, developing, or needing to gain weight and condition. 

Not all horses need concentrates and many horses, even in light to medium work, can do fine on only forage and perhaps some additional supplements. Feed companies often fortify these mixes and pellets with additional protein for horses needing it for muscle development, healing, or other reasons. 

There are tailor made mixes and pellets available for broodmares, young horses, older horses, and high-level working horses that provide the extra elements that these individual populations need. 

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Balancer and Supplements

Some horses may need additional vitamins and minerals or oils and joint support that are not available in enough quantities in the concentrates. These can often be fed alongside some small forage like chaff if the horse does not require larger meals of concentrates. 

Balancers and supplements are fed in small amounts, a bit like a human taking a vitamin pill. If taken in too high quantities they will just be wasted by excretion. It is important to consult a vet or nutritionist before using supplemental additions as the horse must have the right balance to gain the benefit and sometimes overuse can lead to dysfunction. 

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Hydration

Water is essential for life and horses require it for both physiological functions and moving food safely through the gut. Dehydration can lead to impaction within the gut and cause colic. 

A healthy horse can drink around 5 to 15 gallons (20 to 55 liters) of water every day and even more in hot weather or in heavy work. Always provide horses with access to clean water and in cold weather ensure that ice has not formed stopping them from drinking. 

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Bibliography: 

www.bhs.org.uk. (n.d.). Feeding Horses: Horse Diet & Feed | The British Horse Society. [online] Available at: https://www.bhs.org.uk/horse-care-and-welfare/health-care-management/horse-health/feeding-horses/.

Geor, R.J., Harris, P.A. and Coenen, M. (2013). Equine applied and clinical nutrition : health, welfare and performance. Oxford: Saunders.

Frape, D. (2010). Equine nutrition and feeding. Uk: Wiley-Blackwell.

Melyni Worth (2010). The horse nutrition handbook : [feeding for maximum health, longevity, and performance; evaluating weight and well-beeing; designing a year-round feeding program; understanding proper supplement use and resolving nutritional disorders; managing pastureland for optimal health, safety, and feed value]. North Adams, Ma: Storey Publ.

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