Nutrient Requirements: Essential for your Horses

Last Updated on November 10, 2020 by Allison Price

What Nutrients Does a Horse Need? – The Horse

How do you feed your horses?

With many available resources, sometimes you might confuse what could be the best feed supplement for your horses. Horses can use forages and other available roughages as a source of nutrients. For years, horse owners believed that a good roughage should consist of 50 percent of the total equine ratio per weight. However, in this generation, horses should have at least 1.5-2 percent of forage relative to their body weight. The maximum daily intake of dry matter of horses should be 2.5 – 3 percent, therefore the ratio of equine should consist of forage or its substitutes. 

Nutrients should be given to horses with careful observation to meet the nutritional requirements. Appropriate supplying of nutrient to your horses requires knowledge of feeds, nutritional management and requirements.

Most of the horse owners fed their horses with commercial feeds or those mixed feed comes from nutritionists. With this, it is necessary to know the basic nutrient requirement of your horse’s feed supplement.

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Nutrients Need for Horses 

Supplying nutrients into your horses should be safe and meets the required level. The nutrients have four basic classes – water, minerals, vitamins, protein, and energy. 


Horse owners neglect the importance of water, thinking that it is not a nutrient. Horses that have a lack water intake may lead to illnesses and worse to death. The requirement may vary. Horses in a hot environment or those who sweat a lot need to have plenty of water intake. The water intake of horses should be observed. Also, supply your horses with clean and freshwater for them to avoid any contamination. A 500-kg horse should drink 21-29 liters of water per day when you fed them with mixed grain or hay ration or even pasture. If you will feed them only with dry hay, the water intake would be doubled. Also, when your horses exercise in hot weather, they will need to drink 72-92 liter of water. It will replace the excessive loss of water in the body. Moreover, lactating mares should have an intake of water for at least 12- 14 liters per 100 kilograms of their body weight in sustaining good production of milk and health.


It is an organic compound that horses need for their body to function properly. There are various types of vitamins – water soluble and fat soluble. Water soluble is being absorbed with water and fat soluble is being absorbed with fat. The vitamin K, D, A, and E are the fat-soluble vitamins.; while vitamins B and C are water soluble vitamins. Commercially formulated horse feeds frequently supplement fat soluble vitamins with water soluble vitamins at levels beyond the proposed specifications, so there is no need for on-site supplementation. Excess consumption of fat-soluble vitamins D and A is harmful as the body badly excretes fats and the substances soluble in horses. Excessive consumption of water-soluble vitamins is seldom harmful, since the body readily excretes water-soluble substances.


Minerals serve as an inorganic compound that facilitates the different body processes. It is also needed by the body tissue of horses to function effectively. The two minerals that horses needed the most are the phosphorus and calcium. It is necessary for tissues that are growing to have these minerals (calcium and phosphorus). Also, it is relative to horses to have enough amount of calcium and phosphorus when bones are growing. The total diet of horses should contain lesser phosphorus than calcium since excessive amount of phosphorus may hinder the absorption of calcium. Diets for horses should have 1.5 to 2.5 times calcium than phosphorus.

Aside from phosphorus and calcium, there are other minerals that your horses need. These minerals are the copper, zinc, sodium, potassium, and magnesium. About 0.5 percent of salt or sodium chloride can be found in feeds. Moreover, horses need less copper and zinc than calcium and phosphorus. These minerals play a vital part in growing horses.

Magnesium – the maintaining magnesium requirement for horses requires to have at least 0.015 gram/kilogram of body weight based on studies. Working horses should have an estimated requirement of 0.019 to 0.03 gram/kilogram of body weight. The required estimation for the growth of horses is 0.07 percent of the total ration based on limited studies. Furthermore, most feeds for horses contains 0.1 to 0.3 percent of magnesium. There are some report cases that hypomagnesemia tetany hits the stressed horses and lactating mares. The limit intake of magnesium beyond its normal range is 0.3% in the dry matter based on the data of other species. However, there are several horses fed with higher magnesium content but do not show any signs of illness. The intake of magnesium for horses can calm them but an excessive amounts might be toxic.

Potassium – The maintenance intake of adult horses for potassium is 0.05 gram per kilogram of their body weight. Most forages contain less than one percent of potassium that is sufficient enough for horses. The lactating mares, horses receiving diuretics and working horse need to have higher intake of potassium. Moreover, the most common used for ration is the potassium chloride. Maximum level of intake for potassium has not been yet established so excessive amount of it might lead to serious health problem. Also, forced oral potassium supplement should be avoided for hard working horses.


Amino acids can be found in protein, and horses are required to have more amino acids. These acids produce and maintain the muscle of horses, hormones and enzymes, and also have other roles in various body parts. In small intestines, the broken down of protein into amino acids take place and absorbed by the wall of it. Otherwise, the microbes of large intestine and cecum will breakdown the proteins beyond the level of amino acid.

Some amino acids should be included in the diet of horses since horses cannot produce them. Feed supplements that contain essential amino acids are most likely a high-quality source of protein. Feeds also vary on how amino acids of protein distributed and the amount of protein it contains. Soybean meal as an example, it has more lysine compared to cottonseed meal. For you to ensure the balance of amino acids, the lysine minimum level must be at or beyond 4 percent of the total intake of crude protein.

Proteins should be given to horses in ration. Like any other nutrients, horses should digest protein for it to be useful. In addition, horses can digest protein in grain byproducts and grain compared to the protein of forges. For your horses to maintain their body weight, they need enough protein intake. Like with energy, as the horses grow and if they have a lot of work, the protein requirements increase.

You can increase the protein of your horses without changing the level of protein concentration in their diet. There are situations that will require high protein density to meet the high demand of nutrients. Also, the diet for lactating and growing horses can be change according to their needs compared to other horses formulated diet. The high demand of protein intake of your horses could be met by increasing the other energy requirements. 

Horses that are growing need to have protein from 14-16 percent of total ration while mature horses should have 8-10 percent of protein of their total ration. Those aged horses may need to have same amount of protein intake as for young horses. However, when you increase the protein intake of your horses, renal and hepatic function should be assessed. The fetal growth upon their last third pregnancy needs to have 10-11 percent of protein based on their total ration. 


The body of horses utilized the energy as a fuel for various body processes. The unit of energy is Calorie. It represents the standard level of heat produced when the organic compound is broken down. 1 million calories or 1000 calories is the energy requirement for horses every day. 

Feeds have fats, and carbohydrates and protein are sources of energy. Carbohydrates supply more energy in horses. There two type of carbohydrates: the non-fibrous and the fibrous. Carbohydrates that are fibrous provide plan structure. Horses do not have the capability of digesting fibrous carbohydrates. Thus, bacteria and protozoa are responsible in breaking down fibrous carbohydrates. Some portions of the microbial digestion products are being absorbed by horses and used it for energy. These microbial bacterial can be found in the large intestines and cecum.

Fibrous carbohydrates main types are cellulose and hemicellulose. The efficiency of digesting the fiber will decrease as the number of cellulose increases. Hemicellulose on the other hand has a little amount of affecting the fibrous digestibility. Moreover, lignin the indigestible compound that can be found in plants is very important. This lignin cannot be digested by horses’ microbes or enzymes inside their digestive tract. As the amount of lignin increase the digestibility of cellulose gradually decreases. Also, when the plant become mature, the amount of lignin and cellulose increases and made the plant hard to digest.

The amount of fibrous carbohydrates may differ between part of the plants and plant types. Horses could have hard time in digesting plants with few leaves and large stems. Hay and pasture plants are fibrous carbohydrates than those harvested grains. Grains content large number of nonfibrous carbohydrates compared to harvested forages or most gazed.

Non-fibrous carbohydrates are sugars and starch. The analyses between nonfibrous and nonstructural carbohydrates depends on the same type of carbohydrates. When plants become mature and growing, there is a significant increase in the level of nonstructural carbohydrates. Various plants and grains differ on how much carbohydrates they contain. Wheat and corn as an example of having more sugars and starches than oats.

Horses can digest faster the nonfibrous carbohydrates compared to fibrous carbohydrates. Nonfibrous carbohydrates can partially be broken down by enzymes of horses and absorbed by the wall of the small intestines. Furthermore, undigested nonfibrous carbohydrates at the small intestines are broken down by microbes in cecum and large intestine. The portion of energy produce of the fermentation will use by horses as energy. 

If you will feed your horses with large amount of nonfibrous carbohydrates, there will be a chance that also large amount of it will go to cecum and large intestines. The microbes will now digest the digest the nonfibrous carbohydrates. Building up of large amount of substance above the normal state will lead to colic and laminitis. With this, the amount of nonfibrous carbohydrates that will be given to horses should be regulated.

Moreover, fats are chemical compound that composed of oils, fats, and waxes that have fatty acids. Horses need fatty acids because they can’t produce it on their own. Also, they can have twice of energy when fats are breakdown. Feeds have lesser amount of fats compared to proteins and carbohydrates. When the carbohydrates removed from grains, the amount of fat percentage will increase. Adding a certain oil byproduct or putting vegetable oil to feed will increase the amount of fat content of it. The body of horses breaks down the protein for them to use it as energy. Also, adding carbohydrates and oils for energy production are more efficient.

Horses that are mature and have large weight need to have more energy intake. Also, those horses that are working should have enough supply of energy source compared to nonworking horses. Furthermore, growing horses, mares that produce foals, and lactating mares should have enough fuel of energy. Also, when the weather is cold, there is a high amount of energy needed by horses.


Sometimes, horse owners used electrolytes to boost health of their horses. There are several studies that shown the effectiveness of supplying electrolytes to horses especially to those who are hard-working. These can also be beneficial to horse that is for racing or endurance event and if your horses have excessive sweating.

The electrolytes have different formulas such as potassium, magnesium, sodium, calcium, chloride and other minerals. You should avoid commercial electrolytes that includes sugar and dyes in their formula. For you see the effective of electrolytes, add it into the feed of your horses than to the water. With this, you can make sure that your horses can take enough electrolytes. Furthermore, it will help your horses when you supply them with electrolytes ahead of time before the event and continuing it for few days after the event. In other cases, low number of electrolytes might be recommended in on going practice.

You should make sure to follow the prescribed number of electrolytes that should be given to your horses. You can consider the to only have electrolyte supplement that contains salt since other minerals can be found in feeds.

For you to broaden your knowledge about the nutrient requirements of horses, watch this video:

Allison Price
Allison Price

I’m Allison, born and raised in San Diego California, the earliest memory I have with horses was at my grandfather’s farm. I used to sit at the stable as a kid and hang out with my Papa while he was training the horses. When I was invited to watch a horse riding competition, I got so fascinated with riding!