Understanding Digestible Energy for Horses

Shane Wolcott

One of the most basic aspects of equine nutrition is understanding how to use it to achieve the optimal balance for athletic performance. The digestible energy contained in the foods horses consume will affect both their performance and their overall health.

What Is Digestible Energy?

Digestible energy (DE) is the amount of energy in a horse’s feed minus the amount they lose via the feces. It is the amount of energy absorbed by the horse that is used for performance, growth, and other important functions.

Why Is It Important to Understand Digestible Energy?

Understanding digestible energy for horses is important for several reasons.

To Provide the Right Balance of Nutrients

Understand DE provides information regarding whether or not a horse is receiving a mix of nutrients that will meet their energy requirements, production status, and use class.

To Ensure Efficient Rate of Digestion

DE is also important to understand because it helps owners to know which compounds in a particular type of feed are being digested most efficiently by their horse.

To Avoid Excess Stored Energy

Understanding DE helps owners to avoid overloading the digestive capacity, which increases the amount of stored energy or fat in the horse’s body that can lead to metabolic disorders, laminitis, and other diseases.

To Avoid Energy Deficiency

Insufficient dietary energy will result in decreased energy for performance and stamina. It can also cause a loss of muscle mass and increased acidity of blood metabolism via the breaking down and conversion of muscle tissue to energy. Understanding DE will help your horse obtain the required energy from what they consume.

How Is Digestible Energy Calculated?

The DE of any feed is measured in terms of megacalories per kilogram of feed, or Mcal/kg. The amount of DE that any given horse requires will differ according to several factors.

Determining Class

For the purposes of accuracy, the following define light, moderate, heavy, and very heavy work, as defined as follows:

Light work – 1-3 hours of work per week, consisting of 40% walking, 50% trotting, and 10% cantering, at an average heart rate of 80 bpm

Moderate work – 3-5 hours of work per week, consisting of 30% walking, 55% trotting, 10% cantering, and 5% low jumping, cutting, or other skill work, at an average heart rate of 90 bpm

Heavy work – 4-5 hours of work per week, consisting of 20% walking, 50% trotting, 15% cantering, and 15% galloping, jumping, or other skill work, at an average heart rate of 110 bpm

Very heavy work – 1 hour of speed work to 6-12 hours of slow work weekly, at an average heart rate of 110-115 bpm1

Daily DE Requirements According to Class

Because no standard DE calculation method exists, there are multiple ways to calculate it. Therefore, the following daily DE requirement amounts, as well as any listed DE formulas should be considered as estimates only. Always consult a veterinarian for specific information regarding DE requirements for the class and capacity of your horse.

A maintenance or no work horse will require the following:
400kg/880 lbs – 13.3 DE
500kg/1100 lbs – 16.7 DE
600kg/1320 lbs – 20.0 DE

DE formula: 33.3 kcal/kg x BW (body weight in kg)

A light work horse will require:
400kg/880 lbs – 16.0 DE
500kg/1100 lbs – 20.0 DE
600kg/1320 lbs – 24.0 DE

DE formula: 1.2x (0.0333 x BW) (body weight in kg)

A moderate work horse will require:
400kg/880 lbs – 18.7 DE
500kg/1100 lbs – 23.3 DE
600kg/1320 lbs – 28.0 DE

DE formula: 1.4x (0.0333 x BW) (body weight in kg)

A heavy work horse will require:
400kg/880 lbs – 21.3 DE
500kg/1100 lbs – 26.6 DE
600kg/1320 lbs – 32.0 DE

DE formula: 1.9x (0.0333 x BW) (body weight in kg)2

An early lactating mare will require:
400kg/880 lbs – 25.4 DE
500kg/1100 lbs – 31.7 DE
600kg/1320 lbs – 38.1 DE3

DE formula for lactating mares between 200 and 299 kg:

DE formula for lactating mares between 300 and 900 kg:

A late gestation mare will require:
400kg/880 lbs – 18.6 DE
500kg/1100 lbs – 21.4 DE
600kg/1320 lbs – 30.0 DE

A weanling of 6 months will require:
400kg/880 lbs – 12.4 DE
500kg/1100 lbs – 15.5 DE
600kg/1320 lbs – 18.6 DE

How Does Understanding DE Help You Formulate a Dietary Plan?

Understanding DE can help you be more informed when feeding your horse. The ability to calculate your horse’s digestible energy needs will allow you to formulate a plan that delivers all of the dietary energy sources, including protein minerals and vitamins, in optimal combinations.

DE reveals another aspect of nutrition quality, and it can help you to avoid feeding too-large amounts. Understanding DE also allows you to obtain a more accurate digestible energy content in the feed you use instead of relying on manufacturer-listed amounts alone.

There is no doubt that digestible energy is an important factor when it comes to the overall health and performance of your horse at every age.

Top-Quality Equine Products, Created with Passion

Equi-Herbs sources only the best natural ingredients for our products because horses are our lifelong passion. Our metabolic series, aid series, and performance series all help owners to optimize horse health and keep them fit.

Our individual products assist you with addressing inflammation, eliminating infection, easing digestion, and so much more. When you offer these all-natural products to your horse, they can enjoy higher quality of life with more energy, better performance, and less disease.

When you’re ready to explore our product lines and individual supplements, we invite you to shop at our website. You can also speak with our team by calling 1-800-786-0708.


  1. https://thehorse.com/156680/work-level-and-feeding-horses/
  2. https://www1.agric.gov.ab.ca/$Department/deptdocs.nsf/all/agdex12189/$FILE/460_51-1.pdf (DE formulas only, and for light, medium, and heavy work horses only)
  3. https://equinenutritionnerd.com/2014/06/12/digestible-energy-in-the-equine-diet/
  4. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/digestible-energy