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Nutrition for the performance horse

So how does all this relate to the performance horse? The main things to consider about your performance horse are: age and workload.

With all the performance feed choices out there, how does one choose which one to use? This all depends on what your horse is being used for, how hard they are worked and how often they are worked. What are your horse’s energy needs?

Protein and the performance horse

Horse’s growth plates do not close until around 4 years of age and, therefore, should be considered to fall into the ‘still growing’ category until this age. For the still growing 4-year-old, I do believe they need a higher protein, 12-14%, simply because they are still developing. Most performance feeds have a 14% protein. However, the protein level is something to take a closer look at according to what your sport of choice is. As stated above, the horse produces energy through metabolism of protein, carbohydrates and fat. However, this metabolism produces a lot of heat that the horse must then dissipate. Protein metabolism produces far greater heat than carbohydrates and fat; therefore, protein is an inefficient source for energy. The horse dissipates this heat in two ways, sweating and respiration. Increased respiration means increased heart rate. Increased sweating, means loss of electrolytes. Loss of electrolytes, if not replaced, means less blood volume and decreased ability to dissipate heat. I will go into electrolytes in further detail below under ‘Electrolytes.’

Fat and the Performance Horse

Fat is a very important component to your performance feed. A lot of research and knowledge has been gained on fat in the performance horse’s diet.

Fat provides energy for aerobic activity but not anaerobic work, meaning that the horse will pull all their energy requirements from fat during aerobic activity, saving their stored muscle glycogen for anaerobic activity. This is important because muscle glycogen produces lactic acid during anaerobic activity and lactic acid is not produced through the breakdown of fat during aerobic activity; thus, extending your horse’s endurance and helps delay muscle fatigue.

If your feed of choice does not have a sufficient amount of fat to keep up with your horse’s demands, you can supplement with a fat supplement. It is wise to increase your fat content before increasing the daily ration of grain. Besides just a healthy shine, fat is a good source of Omega 3 and 6 essential fatty acids (EFTs), which provide many great benefits, including cell health and better absorption of fat-soluble vitamins (E, A and D). It is important to know your fat source not only in your feed but also when choosing your fat supplement as not all fat sources are equal in their Omega content.

It is also important to know there is a Omega 3:6 ratio that is as important as the calcium:phosphorus ratio and should be kept in balance. The ratio should be 1:5 (Omega 3 to 6). There are two basic EFT families, Omega 3 and Omega 6. Omega 3 is made from alpha linolenic acid and Omega 6 is made from linoleic acid; the horse’s body uses both of these to produce other EFTs. The correct balance/ratio of the EFTs is essential to maximizing immune, antioxidant and anti-inflammatory responses (reducing muscle damage and fatigue, improving cellular repair and recovery, and maintaining cell function for efficient oxygen and electrolyte and lactic acid secretion and excretion).

Omega 9 is not an essential fatty acid as this is naturally produced by the horse. Stearic acid and oleic acid are examples of Omega 9 fatty acids.

Rice bran is very high in phosphorus, something any owner should avoid unless supplementing with extra calcium to make up for this so as not to upset the calcium/phosphorus ratio. Most commercially prepared feeds that use rice bran as a fat source will compensate with extra calcium somewhere; just be aware of this fact and check your labels. Or, for the owner that feeds straight rice bran, this high phosphorus content can be offset by feeding alfalfa, which is high in calcium. Alfalfa is also a great natural GI “buffer.” As stated above, too much phosphorus in comparison to calcium inhibits calcium absorption and causes bone demineralization.

Beet pulp is a great roughage source to add to your horse’s daily ration. Because it is so high in fiber, it is considered a very safe feed to use. It is also a good feed to use on that hard-keeper as it helps them maintain weight better and is a better choice than increasing grain intake. I like to use the shredded beet pulp as it requires less soaking than the pelleted form, which can require 12 hours of soaking prior to feeding.

If I have a hard keeper, I add a fat supplement and/or beet pulp before increasing the amount of grain. The amount in pounds I feed depends on the horse’s body condition, metabolism, and workload. Every horse is different and must be evaluated based on their personal needs.


Understanding electrolytes, why and when we give them, is absolutely key to any performance horse’s program. To better understand this, we must understand fluid balance in the horse, metabolism, sweating, and the added offense of environmental factors (particularly heat and humidity).

First, I am going to reiterate the fact that high protein feeds and high grain diets produce excessive heat during digestion/metabolism (discussed above in ‘Nutrition for the Performance Horse’). Protein metabolism, in particular, produces far more heat than the metabolism of carbohydrates or fat and, therefore, is an inefficient energy source in the horse’s diet. However, this may be helpful in very cold weather where maintaining heat may be difficult.

How do horse’s dissipate their heat production?

The horse has two primary means to dissipate heat production:

  1. Sweating
  2. Respiration/heart rate

The evaporation of sweat is the primary method the horse uses to dissipate heat. The horse becomes heat-exhausted when he loses the ability to keep up dissipating the amount of heat produced (such as in high humidity). Of interest is that when the vapor pressure of the skin surface is close to the vapor pressure in the air, such as in humid conditions, sweat no longer evaporates. When the sweat no longer evaporates, the horse is no longer dissipating heat through sweat evaporation. Sweat requires evaporation for heat dissipation. Sweat dripping off the skin is not evaporation. Also of interest is the fact that horse sweat has a high amount of latherin, which is a protein. It is this protein in horse’s sweat that is the cause of lather and also promotes the spread of sweat over the skin to increase evaporation. This is why lather is one of the first visible signs of heat stress in a horse, meaning he is producing a large amount of heat and is having a hard time dissipating this heat. This is all important knowledge particularly for the endurance horse.

The horse will also dissipate some body heat by increased blood flow and panting. Increased blood flow means increased heart rate. A well-conditioned horse that is panting may still recover his heart rate within a reasonable amount of time, but he is panting to achieve this and, therefore, this is a sign of excessive work.

How do we replace all the fluid loss caused by heat dissipation?

Particularly in the endurance horse or any horse working for many hours out of the day, we probably don’t. But, with any performance horse, we need to understand what is needed, when and why, what signs to recognize and what they mean. The key is to keep the horse hydrated and not let him become dehydrated. Once he is dehydrated, it is a chasing game. It is important to give electrolyte supplementation prior to the horse becoming dehydrated.

The volume of sweat our horses lose obviously results in a great loss of body fluid. And, in this loss of body fluid, is a great loss in electrolytes. Horses cannot store electrolytes so it really is not beneficial to load your horse with electrolytes days in advance. It is important, however, to keep electrolyte balance at all times as much as possible. The large intestine can store a large amount of water, so one way to try to keep excess water and electrolytes in your horse is by feeding adequate hay/roughage. Beet pulp is a great source of roughage and a great water “container.”

When a horse sweats, this fluid has to come from somewhere, right? The blood plasma carries a lot of electrolytes throughout the body. The mineral electrolytes lost in the horse’s blood plasma through sweat are chloride, potassium, calcium and magnesium.

When we lose electrolytes in the blood plasma, the blood volume decreases. When the blood volume decreases, blood flow to the skin decreases. When blood flow to the skin decreases, sweat production decreases. When sweat production decreases, the horse loses his ability to cool down. You’ve heard of the term, anhidrosis – this is the inability to sweat.

While dehydration is causing the loss of electrolytes and the blood pressure to drop, the muscles are beginning to use their store of glycogen, which increases heat production and increases the heart rate (also more heat), and then lactic acid production due to the glycogen utilization… now we have a dehydrated horse and a muscle-fatigued horse. If kept up, this horse will soon suffer from tying up or colic (this is discussed in greater detail under ‘Colic and the GI System’ and ‘Tying up and Muscle Fatigue’).

If these processes discussed above continue, both the GI tract and the nervous system are affected and the horse can lose his ability to voluntarily drink and, in severe cases, the horse loses his thirst reflex and refuses to drink under any circumstances. Obviously, this horse needs immediate veterinary attention.

Signs of dehydration to look for:

  • Slow capillary refill time (2-3 seconds) – this is an indicator of dehydration by decreased blood flow to the skin
  • Increased skin tent – when pinched, the skin remains pinched or is slow to “bounce back”
  • Dry or pasty mucous membranes
  • Dry feces – small, tight stools
  • Increased heart rate

The signs listed above are common in a moderately dehydrated horse. It is important to understand, it does not take a whole lot more stress for the horse to continue to decline and require immediate veterinary attention.

Above, we discussed the main electrolytes lost in blood plasma, which decreases the blood flow to the skin. The main electrolytes lost in sweat are sodium, chloride and potassium. Excessive loss of these results in muscle fatigue and decreased thirst reflex to dehydration.

How much electrolytes do I supplement for my horse?

This depends on how much sweat is lost. How much sweat is lost depends on environmental factors (heat/humidity), duration of exercise, and intensity of exercise. It is hard to give a median here without doing some blood chemistry. There has been some research done at endurance events, taking blood samples throughout a 50 or 100-miles course. In most studies, potassium frequently came up low. Potassium loss causes decreased muscle strength and tone. Again, it is important to give electrolytes prior to dehydration; the goal is to keep the horse from becoming dehydrated.

Remember, without proper water and electrolyte balance, the horse loses his ability to cool himself, and a horse can only efficiently sweat (and, thus, cool himself) if he is not dehydrated. And, of course, a horse cannot stay well hydrated without proper water intake and electrolyte balance (in addition to your B group vitamins). Electrolytes are lost in sweat, urine and feces and include sodium, potassium, magnesium, calcium, chlorides, sulphates, posphates, and bicarbonates.

  • Sodium and chloride are the main electrolytes lost in sweat. Sodium helps keep water levels balanced and blood pressure maintained. Chloride helps with acid/base balance.
  • Potassium balances cell fluid levels and is vital for muscle, heart and kidney function.
  • Calcium assists heart, nerve, muscle, and blood clotting functions.

Deficient levels of potassium and sodium causes a decrease in appetite as well as thirst.

>Deficient levels of calcium causes many heart and muscle disorders including muscle fatigue and “heaves.”

B Vitamins

B vitamins play an important role as well in your performance horse’s diet, so I am going to discuss these in a little greater detail.

B vitamins are a group of vitamins that are water soluble and are not stored in the body and, therefore, must be taken on a daily basis. The B Group vitamins are needed for many body functions and do play a role in the release of energy. B vitamins are lost in sweat as along with electrolytes. If these vitamins are deficient, poor performance will follow. I will list the B vitamins and their functions below:

Vitamin B1: involved in energy production through carb metabolism. Increased conditioning and sweating increases the need for vitamin B1.

Vitamin B2 or riboflavin: important for energy production from carbs, growth, and utilization of feed.

Vitamin B6 or pyridoxine: works with niacin in energy production and blood cell formation.

Vitamin B12 or cyanocobalamin: involved in metabolism of protein, carbs and fat, and works with folic acid in the maintenance of red bleed cells. B12 contains the mineral cobalt. Cobalt plays a role in carrying oxygen in red blood cells and cobalt deficiency causes anemia.

Other B vitamins:

Niacin – involved in fat, carb and amino acid metabolism.
Pantothenic acid – involved in converting carbs, proteins and fat to energy.
Folic acid – works with vitamin B12 in red blood cell formation.
Choline – Involved in fat metabolism for energy, liver function, nerve impulses, and cellular function.

Trace Minerals

I would like to mention some important trace minerals and their functions as I believe there are some important facts every rider should be aware of.

Selenium is an antioxidant and works with vitamin E. While extra selenium can cause a toxicity, a deficiency can predispose a horse to tying up.

Copper plays an important role in bone development, joint cartilage and connective tissue. Cooper also plays a role in the utilization of iron.

Zinc is essential in the development of the hoof, bone and cartilage.
Key points to remember:

  • Electrolytes are not stored by the body.
  • Keep your horse hydrated – don’t wait until your horse is dehydrated before supplementing with electrolytes.
  • Remember how your horse needs to dissipate heat and keep in mind your environmental factors in this equation.
  • Know your electrolytes and what their functions are; be sure to give adequate amounts of sodium (often combined with chloride), potassium, calcium, magnesium, and phosphorus.
  • And, don’t forget your B Group vitamins – they are equally essential in the performance horse.

If you would like a customized program for you and your horse, please contact me to discuss your next step in success! See my Personalized Training Program if you would like me to set up a program for you.