Shaping the future of animal health

Feeding Endurance Horses

feeding endurance horsesMany advances in the scientific and practical feeding of endurance horses have been made over the last decade. At international competitions racing speeds are increasing, increasing work rates and subsequently energy demands. This in turn increases electrolyte requirements due to the substantial loss of body water and salts. Failure to compensate for this increased workload may result in poor performance and may also increase the risk for metabolic problems including heat stress and “tying up” (Harris, 2009). Appropriate nutritional management can help to alleviate these issues and reduce the incidence of problems that result in race disqualification or the need for veterinary intervention.

There are many factors which influence the method of feeding such as where the horse is housed (paddock or stable), access to pasture, workload and feed preference of the owner. Many horse owners mix their own feeds, some rely on commercially prepared mixes. There is no single correct method of feeding, however there are some basic nutritional requirements which should be met to promote optimal health and performance.

Basic Nutritional Requirements

The majority of endurance horses are small framed, hardy horses often based on part or pure Arabian bloodlines. Even though robust and strong, these horses naturally have a reduced capacity for bulky feeds, with a risk of reduced appetite imposed by the stress of extended exercise in preparation for competition. In many cases, the diet has to be manipulated to ensure each individual horse can consume an adequate volume to meet requirements.


A horse with a BCS of 4 - 5

Although endurance horses utilise their muscle energy stores very efficiently through aerobic (oxygen) metabolic pathways, the extended duration of exercise results in depletion of over 50% of their muscle glycogen energy stores during a standard 80-100km ride. Although energy is not diverted for growth, as all competitive endurance horses are mature, adequate energy must be provided for exercise, tissue repair and to maintain body condition during extended training.

The horses body condition score (BCS) and body fat content may influence performance during endurance rides. It has been suggested that in more difficult rides, thin horses (BCS <3 on a 9 point scale) may be disadvantaged because of lower energy stores and muscle mass while horses with a BCS of >6 may have problems due to the extra weight and impairment to heat dissipation. It is recommended that feeding programs result in a BCS of 4 to 4.5 on the 9 point scale (Harris, 2009).

All horses are individuals and the actual energy requirements for each horse will vary according to that horse’s body weight, workload (duration and intensity), environmental conditions, terrain, weight of rider and tack, ability of rider and fitness of the horse.

The four main sources of energy are fibre, carbohydrates, and oil (fat).

Roughage - Fibre

Roughage should be the foundation of the diet for all horses and is important for the maintenance of hindgut function and health and for a reduction in the risk of gastric ulceration and abnormal behaviours. In a recent paper, prevalence of gastric ulceration was found to be high (67%) in horses competing in a 50 or 80km endurance ride (Nieto et al., 2004). Fibre provides “slow release” energy and continues long after it has been ingested. Fibre also helps to maintain hydration during exercise. However high fibre diets may increase hindgut weight which may create a disadvantage for the high performing endurance horse. It is recommended that horses receive at least 1kg of forage (hay or chaff) per 100kg body weight. Very mature forages should be avoided and hay should be of a low-to-moderate protein content (such as grassy/meadow hay or a grass/Lucerne mix where lucerne is no more than 30% of the mix)  (Harris, 2009).

Cereal Grains - Carbohydrates

Many successful endurance horses are maintained on relatively small amounts (2 - 4kg) of grain each day, particularly those that have access to pasture, as they are more settled and tend to do better. Endurance horses also seem to be more sensitive to over-supply of energy in grains, with increased risk of tying up and unsettled behaviour. 

Starch, a carbohydrate is the principal component of cereal grains (approx. 44% of oats, 55% of barley and 70% of corn (Equi-Analytical, 2013)). Large cereal based meals may overwhelm the small intestine and as such it is recommended to feed no more than 300g of starch per 100kg bodyweight per meal for a 450 kg horse (Harris, 2009).

Soyahull pellets

Alternatives to grain

Grain-free alternatives such as soyahulls and sugar beet pulp are becoming increasingly popular.  These feeds are high in fibre, however the fibre is more digestible and has a higher energy yield. 


There is an increasing trend for rations to now include more fat to reduce the bulk of the ration a horse has to consume to meet its energy needs for long distance exercise. Studies suggest this may help to improve exercise endurance (Eaton et al., 1995). Fat, as polyunsaturated vegetable oil, is a low bulk, low “fizz”, low heat waste energy booster ideally suited to increasing the energy density of the ration.  Fat can be metabolised for energy during aerobic trotting and cantering speeds, and helps conserve muscle glycogen (high energy sugars) during prolonged exercise.

A practical level of oil inclusion in the diet would be up to about 2 cups per day, replacing 1 ½ kg or 3 litres of oats to reduce bulk in hard working, small framed horses. Oils should be introduced to horses gradually to avoid digestive upset.

With the exception of some vitamin E, vegetable oils do not provide other nutrients. A balanced vitamin and mineral supplement such as Feramo Every Horse may be required to maintain dietary balance. Studies also suggest that the requirement for vitamin E increases with increasing polyunsaturated fatty acid content. This may be achieved by supplementation with White-E.


Adequate good quality protein intake is essential to maintain muscle mass, especially under hard training as many horses drop away over the rump and croup, particularly after a hard, long distance competitive ride. Excess protein is undesirable as it not only adds unnecessary cost but it may also negatively affect heat production, acid-base balance and possibly respiratory health. Protein quality (as opposed to quantity) is of upmost importance. Some high quality protein sources include full fat extruded soyabean meal and lupins.

Minerals, Electrolytes and Vitamins

Individual horses have changing needs relative to their age, exercise level and appetite. Although a ration may meet major nutrient demands for energy and protein, it may be low or imbalanced in calcium, phosphorus, other minerals, electrolytes and essential vitamins to meet daily needs of a long distance horse. Supplementation with additional calcium to maintain bone strength and replace sweat losses, Vitamin E for muscle function and aerobic metabolism, and Vitamin A to maintain tendon strength are widely used to ensure an animal can perform and remain fit and sound over extended training periods and longer competitive seasons. 

Optimum Vitamins and Trace Elements

A well formulated and balanced vitamin and trace mineral supplement, such as Feramo Every Horse, will help correct low and imbalanced levels of essential nutrients in low bulk, higher grain feeds.  Nutrients provided by each dose of Feramo Every Horse include:

  • Feramo Every Horse

    Cobalt, which is integral in synthesis of the Vitamin B12 and is involved in the formation of the oxygen carrying component of red blood cells.  A deficiency can result in anaemia;
  • Copper, which is required for the development of bone, joint cartilage, elastic connective tissue, uptake and utilization of iron and copper containing metabolic and tissue anti-inflammatory enzymes;
  • Iodine, which is incorporated into the hormone thyroxin in the thyroid gland and regulates the metabolic rate;
  • Manganese, which contributes to carbohydrate and fat metabolism and formation of chondroitin sulphate in cartilage of joints;
  • Selenium and iron, to help improve performance and immunity;
  • Zinc, which is essential in bone, cartilage and hoof formation;
  • Vitamin A to help maintain tendon strength in hard working horses;
  • Vitamin D which is critically concerned with the absorption, regulation, metabolism and excretion of calcium and phosphorus;
  • B Group vitamins which play a role in the release of energy, and are needed for numerous essential body functions. 
  • Biotin, for improving the hardness, growth rate and quality of the hooves and laminae strength.
  • Amino acids, to help replace tissue degradation and losses in sweat in working horses.

Cal-Plus with Biotin


Endurance horses require adequate calcium to maintain muscle function, bone and joint strength during extended training. Calcium stores in bone are depleted by bone demineralisation due to concussion and loading stresses, and heavy sweat loss. On fat boosted diets, extra calcium must be provided to offset the reduction in overall calcium intake relative to demand.

Additional calcium and bone minerals are provided by 60g Cal-Plus with Biotin daily, with up to 90g daily in heavy sweating, long distance horses. The biotin in this supplement will also help horses with shelly, soft and crumbly hooves.

Vitamin E


Vitamin E is an important antioxidant in muscle and tissue cells, and is essential to help ensure efficient aerobic energy use and the protection of fats metabolised in the muscle cells during exercise. A daily intake of at least 1000 IU of Vitamin E protects cell membranes against oxidation and risk of harmful compounds interfering with muscle activity.

Most competitive horses benefit from 1000-1500 IU of Vitamin E daily. Natural Vitamin E, as in White-E powder, is a fat soluble stored form of Vitamin E that maintains higher levels in muscle, blood and tissue. 


Fluid and electrolyte replacement is essential to combat sweat loss and maintain vitality and performance.  Heavy sweating horses have higher replacement needs for a range of electrolytes lost in sweat. Sweat losses of 40-60 litres per day deplete fluid and electrolyte reserves.  Large amounts of potassium relative to blood reserves are lost in sweat (each litre of sweat depletes 20 litres of blood potassium reserve), as well as chloride, sodium, magnesium and calcium. Humidimix

Losses of potassium and chloride can result in alkalosis of the blood, with symptoms of spookiness, blowing hard when exercising and during recovery and risk of tying-up in fatigued horses. A daily supplement of 2 scoops of Humidimix will help to maintain optimum blood and muscle electrolyte levels in heavily sweating horses during training and competition.


Where horses are travelled over long distances, a dose of 80mL of Recharge Rehydration Concentrate over the tongue, with cool water to drink, before and after travelling, will help to rapidly restore electrolyte and fluid levels. Carrying 60mL of Recharge in a syringe on a ride and giving it over the tongue prior to allowing a horse to drink at a creek, dam or trough, and at the start of a check point recovery period will help to rapidly counteract dehydration and maintain vitality and stamina.



  • Eaton, M.D., Hodgson, D.R., Evans, D.L., Bryden, W.L. and Rose, R.J. (1995).  Effect of a diet containing supplementary fay on the capacity for high intensity exercise.  Equine Vet. J. 18; 353-356.
  • Equi-Analytical Laboratories (2013) 
  • Harris, P. (2009).  Feeding management of elite endurance horses.  Vet. Clin. Equine 25; 137 – 153.
  • Nieto, J.E., Snyder, J.R., Beldomenico, P., Aleman, M., Kerr, J.W., Spier, S.J. (2004).  Prevalence of gastric ulcers in endurance horses – a preliminary report.  Vet J. 1; 33 – 37.


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