Feeding Endurance Horses Day to Day

Endurance horses are arguably the most complicated equine athletes to feed correctly. Although research on feeding for long-distance, low-intensity work is still ongoing, equine nutritionists have devised a general nutritional strategy based on current knowledge to give you and your horse the best chance of success, whether you want to be first over the line, or you just want to complete the ride with a happy, healthy horse.

At the Kentucky Equine Research (KER) facility in the United States, five Arabian horses were used specifically for endurance research. The results of feed trials with these horses, along with international consultation to a huge number of clients, led to a better understanding of how nutrition affects performance, and how critical correct nutrition is for the endurance horse. The following recommendations for day to day training are based on KER’s research and experience with endurance horses.

Feed diets high in good-quality forage such as pasture, grass hay, or mixed grass/legume hay. These forage sources can be fed free choice to endurance horses. Horses have evolved to survive on forage, so it is the best possible feed for gut health. Forage provides slow-release energy that is by far the most important energy source for endurance horses. Pasture is best when it is good quality, containing high levels of protein and most of the essential vitamins and minerals.

Lucerne (alfalfa) hay is beneficial as it is high in energy, but its use should be limited, as high daily protein and calcium levels can be detrimental to race-day performance. High levels of calcium in the daily diet can interfere with calcium mobilization from bone for use during work. High-protein diets increase body heat, urine production, and water needs—all bad news for endurance horses. It is a good idea to feed lucerne as chaff mixed with hard feed rather than as the major forage source. Apart from supplying essential dietary energy, hay and forage stimulate water consumption. For every kilo (2.2 lb) of dry hay intake, horses consume up to four litres (one gallon) of water. This can be very beneficial when trying to get horses to drink during and after a hard training ride.

Feed a high-fat diet. During exercise, it is desirable that endurance horses utilise fat rather than muscle and liver glycogen as their major energy source. Feeding fat on a daily basis during training gets the horses’ metabolism used to utilising fat during exercise. Research has shown that endurance horses fed fat for a period of eight to ten weeks mobilise and utilise fat to a greater extent during exercise than horses not fed fat or given fat only in the short lead-up to the race. High-fat feeds, oils, and rice bran products are all excellent sources of fat for endurance horses. Diets high in fat have the added advantage of being more energy-dense, meaning that you can feed less than conventional grain diets and still get the same amount of energy, which is great for horses with poor appetites.

Supplement electrolytes. During daily training, a good-quality electrolyte supplement can be invaluable. If conditions are hot and humid, electrolyte requirements are elevated. As horses sweat during training, they lose salt as well as water. Sweating increases thirst as body salt concentrations increase with the loss of water. Providing electrolyte supplements after training rides replenishes body salt concentrations and stimulates thirst. Feeding 50 g of loose salt per day in feeds is a good way to maintain sodium and chloride levels during early training stages and can be continued right through to competition as insurance against sodium imbalances. A commercial electrolyte containing all four essential electrolytes should be used on hard training rides.

Feed sufficient energy for work. There is no reason for endurance horses to look overly lean and skinny, though many horses are seen with obvious ribs and pronounced hip bones at endurance events and are accepted as the norm. Although excessive weight is undesirable, good body condition is vital for health and performance. Endurance horses have extremely high daily energy requirements. As well as forage and fat, starch in the form of grains is an important source of dietary energy. As with all horses, small meals should be given at least two or three times daily, with no more than 2 kg (4.4 lb) of grain in any one meal. Processed grains (i.e., steam-flaked/rolled, pelleted, extruded, micronised) are excellent for endurance horses. They are more digestible than unprocessed grains and reduce the risk of starch overflow to the large intestine. Highly digestible sources of fibre are an excellent slow-release form of energy for endurance horses. In the United States and Europe, endurance riders feed sugar beet pulp and soy hulls as a major part of the diet for their high-fibre, low-starch contents. These are great sources of energy that reduce the requirement for grain and thus lower the chances of grain overload or tying-up during exercise. In Australia, soy hulls are sometimes available, as are lupins, which have similar benefits. Lupins are also high in protein so their inclusion in the diet should be limited to 1.5 kg (3.3 lb) or less per day.

Maintain balanced levels of vitamins and minerals. It is important to maintain balanced nutrition in all horses, but it becomes more important to provide horses with the substrates necessary to build, repair, and maintain correct function of body systems when we place high exercise demands on them. Endurance horses in training require higher levels of many of these vitamins and minerals than horses at rest. A broad-range bioavailable vitamin and mineral supplement should be fed if horses are not receiving a commercial mixed feed already fortified with vitamins and minerals. Vitamin E and selenium are especially important for endurance horses. These are antioxidants that help muscles to cope with and recover after work and increase immunity to disease. Supplemental natural vitamin E can be particularly useful during hard workouts and competitions in maintaining adequate antioxidant levels in the muscle tissue.

Ensure a constant supply of fresh, clean water. A constant concern with endurance horses is ensuring correct hydration levels. This is just as important during training as it is during competition. Encouraging horses to drink at every opportunity starts long before the endurance ride competition. A combination of feed management (i.e., feeding hay and electrolytes to stimulate thirst, wetting feed, and acclimatising horses to eating wet slurry-type feeds during work) and hygiene (cleaning water troughs, buckets, and feed troughs regularly) goes a long way to keeping the horse in tip-top condition before competition and will assist you in the quest for good hydration during the race. Feeding succulents such as carrots and apples can also help provide water to the horse and add interest to the diet.