Equine nutritional glossary

It can get technical at times when talking about equine nutrition. So, to help you better understand your horse’s diet and diet-related health, we have prepared this useful glossary of common (and not so common) nutritional terms.

You can use the alphabetical navigation aid to jump to the term you are looking for.


Ad lib feeding– Offering the horse as much food as they want to eat, particularly important with forage to ensure that the horse has constant access and can eat as much as it wants. Care must be taken with overweight horses.

Amino acids- Known as building blocks, they form chains to make up proteins. They can be split into essential and non-essential amino acids. Essential amino acids cannot be produced by the horse and must be provided by the diet, for example lysine.

Antioxidant- Natural chemicals that bind to free radicals and prevent them from causing damage to cells. Free radicals are a naturally produced by-product when cells use oxygen, however high levels within the body can be dangerous. Things such as intense exercise or ageing can cause excessive levels of these free radicals. Examples of antioxidants include Vitamin E and Vitamin C.


Balancer- Concentrate feed providing vitamins, minerals and amino acids. They help to ensure that the horse has a balanced diet. They are often low in calories and energy. Our Pure Balance provides optimum levels of vitamins, minerals and essential amino acids as well as biotin and a pre and probiotic.

Bioavailable– The rate and degree of which a substance can be absorbed and used in the horse’s body once it has been consumed.

Biotin– A water soluble B vitamin. It can help to strengthen the horn of the horse’s hoof.

Brewers yeast– A type of yeast and a good source of vitamin B.


Calorie– A unit of energy.

Carbohydrate– The collective name given to sugars, starches and dietary fibres found in horse feeds which are digested to provide a source of energy. Carbohydrates are the main energy source in the horse’s diet. They are processed by the horse’s digestive system at different rates. Sugar and starches are broken down quickly, providing a lot of fast release energy. Whereas fibre is digested much more slowly providing a more controlled source of slow release energy.

Chelated– A mineral that is bound to a small protein or amino acid to allow the horse’s body to more easily absorb the mineral.

Choke– When the oesophagus becomes blocked choke can occur. The oesophagus is a strong muscular tube that transports food to the stomach.

Complete feed– A feed designed to supply all the nutrients in the diet, including vitamins, minerals and adequate fibre levels to help maintain digestive health. With the exception of our Pure Linseed, all of our feeds are designed to be complete feeds.

Condition scoring– A means of assessing the horse’s body fat coverage. It can be a way of monitoring the horse’s condition to prevent them losing or gaining too much weight; you can alter the diet accordingly based on their condition score.

Cushing’s- Also known as Pituitary Pars Intermedia Dysfunction or PPID. A disease of the endocrine system of the horse; in particular a dysfunction of the pituitary gland. Horses that suffer from Cushing’s will benefit from a diet that is low in sugar and starch.


DE- Digestible energy– The estimated energy content of the feed. It is measured in MJ/kg and provides a useful measure of the energy that the animal may be able to use from the feed, taking into account digestibility. However, there are no allowances for energy lost through urine and heat for example.

Digestible– A nutrient which can be absorbed in the intestines of the horse.


Electrolytes– Minerals that help maintain water balance and metabolism within the body. They are lost through sweat and urine, along with water. Sodium chloride (salt) is the most common; others include magnesium, potassium and calcium.

EMS- Equine Metabolic Syndrome- A condition in horses characterised by laminitis, insulin resistance and obesity.


Fast release energy– Energy from sources including cereals which are digested quickly by the horse, increasing blood sugar levels and providing energy quickly. All horses need this energy to some degree, but it is particularly beneficial for horses in fast work such as polo ponies.

Fatty acids– Molecules that make up fats and oils. When fats are broken down in the digestive system fatty acids are released, providing a source of energy.

Fibre– A structural carbohydrate which must be broken down slowly by bacteria in the hind gut of the horse in a process known as microbial fermentation. Fibre is the most important part of the horse’s diet!

Fizzy– An excited or high-spirited horse.

Forage– A term used to describe roughages or fibrous plant materials such as hay or haylage.

Free radical- A natural, reactive chemical produced when cells use oxygen. They can be harmful in large quantities.


Glucosamine- A natural compound found in bone and cartilage. Supplementing the horse’s diet with glucosamine can help support the joints.

Glycogen– The body stores carbohydrates in the form of glycogen. When the horse requires energy the glycogen is broken down into glucose.

Good doer– A horse that maintains weight and condition easily. They may have a tendency to put on weight.


Hind gut– The large intestine of the horse.


Insulin resistance– The horse’s sensitivity to insulin is reduced. This means that when insulin is released it fails to exert its usual effect; resulting in more insulin being required to trigger the normal response. As a consequence, the horse can have high levels of blood glucose and blood insulin.


Jejunum– The middle part of the small intestine. The small intestine can be split into three sections, the duodenum which links the stomach, the middle section called the jejunum and the final section the ileum which links the small intestine to the caecum.


Keratin– A fibrous protein that forms the main structural components of hair, feathers and hooves.


Laminitis– In basic terms this is the inflammation of the laminae; the soft tissue structure that attaches the pedal bone to the hoof wall. This results in pain and lameness. Horse and ponies that are overweight or are fed a high sugar and starch diet have an increased risk of laminitis. Horses that suffer from laminitis will benefit from a diet that is low in sugar and starch.

Lysine- An essential amino acid. The horse cannot produce it itself so it must be provided in the diet. Our balancer provides a source of lysine. It is particularly important for muscle development.


Macro-nutrients– Minerals which are required in larger quantities in the horse’s diet. Examples include magnesium, calcium and sodium.

Metabolism- Chemical processes within the body, examples include producing energy.

Methionine- An essential amino acid. The horse cannot produce it itself so it must be provided in the diet. Our balancer provides a source of methionine. Methionine is used for helping to maintain healthy skin and hooves.

Micronutrients– Minerals and elements which are required in small quantities in the diet examples include zinc, copper and selenium.

MSM- methylsulfonylmethane- An organic compound that can help support healthy joints.


NOPS- Naturally occurring prohibited substances. This refers to things that occur naturally in the environment, for example wild plants, but are prohibited in sports horses. The Pure Feed Company is a member of the BETA NOPS scheme and helps to reduce the risk of prohibited substances contaminating the feed.

Nutritionally improved straw- Straw that has been altered either chemically or through cooking. We do not use nutritionally improved straw in our feeds.


Oatfeed- The outer fibrous husk of the oat. It is what is left over after the inner, starchy part of the cereal has been removed. It is a source of fibre.

Omega 3 fatty acids- Essential fatty acids that are important for metabolism and health.


Poor doer– A horse that struggles to maintain weight or condition and can be prone to losing weight.

Prebiotic– Fermentable carbohydrates. They help to feed the good bacteria in the large intestine of the horse. Our balancer provides a prebiotic.

Probiotic– Live microorganism which can live in the hind gut of the horse and add to the good bacteria that are already there. Our balancer provides a probiotic.

Profeed– A type of prebiotic used in our balancer.

Protein– Essential building blocks for the body; it is used for growth and repair. Proteins are made up of amino acids.


Quidding- Dropping food or balls of feed from the mouth when chewing. This can indicate dental problems.


Recurrent Exertional Rhabdomyolysis/ tying up- A disturbance in muscle function causing stiffness and muscle pain. The horse may seem reluctant to move or may only move in small stiff steps. The muscles over the hind quarters often appear hot and hard. It is important not to feed a diet that is high in cereals and starch as this can be a contributing factor.


Slow release energy- Energy that is provided from oil or fibre. It is a more controlled source of energy providing small amounts over a longer period of time.

Soya hull- A high quality source of protein for the horse.

Starch– A non-structural carbohydrate. It is broken down in the small intestine and delivers fast release energy. Cereals are high in starch.


Topline– A combination of correct exercise and high quality protein in the diet helps to build good muscle tone and thus topline. Topline refers to the muscles along the neck, withers, back and croup of the horse.


Urticaria– More commonly known as hives, it describes an allergic reaction characterised by raised, itchy bumps on the skin.


Volatile Fatty Acids (VFA’s) – These are produced by microbes in the caecum and large colon as a result of fermentation of fibre. The VFA’s are then absorbed through the gut wall and used as an energy source by the horse.


Wheat feed- The outer fibrous husk of wheat.

Wholegrain – The whole cereal grain, including the outer fibrous coating and the inner starchy grain. For example, whole oats which are included in our Pure Performance feed.


Yeast– A single celled fungi. Live yeasts can be extremely beneficial for horses as they provide healthy bacteria for the hind gut. Inactive yeasts provide the horse with a source of B vitamins.


Zinc– A trace element that is important for bone, hoof, immune system and skin health. It is also used in many enzymes within the body. Trace elements are also referred to as micro-minerals.