January 2008
AG/Equine/2008-01pr
Meeting the Energy Needs of the Horse
Dr. Patricia A. Evans, Extension Equine Specialist, Utah State University
Yvette Connely, Equine Nutrition Specialist, Land O’Lakes Purina Feed
Introduction
When it comes to feeding, many horse owners
struggle with knowing what and how much to feed.
Confusing words such as energy can also add to the
struggle. When the word energy is mentioned, many
think of it in terms of a horse as being excitable,
uncontrollable or the opposite of not having enough
momentum. The term energy can be used in many
different ways when talking about the horse and
nutrition. In this paper we will answer the question,
“what is energy” and explain how it affects the
horse from a nutritional aspect. For more
information on the horse’s digestive tract see
AG/Equine/2006-01 and AG/Equine /2006-02.
What is Energy?
To put it simply, energy is the fuel used by the
horse for all functions, including maintenance of
body tissues, growth, lactation, performance, etc.
Animals use the energy to produce heat and
adenosine triphosphate, or ATP, which cells then
use to function. Energy itself cannot be measured,
but it can be converted to heat, which can be
measured. We measure the energy stored in feed as
megacalories (Mcal) or kilocalories (kcal).
Kilocalories are also referred to as Calories (with a
capital “C”). So, when we talk about energy, we are
usually really talking about Calories.
Energy Sources for Horses
Horses like any other living being must have an
energy source to continue functioning. Feed
provides this energy. Not all of the feed eaten is
available for energy as it is lost through the feces,
urine or gases and is called indigestible energy. The
portion lost consists of indigestible food stuffs as
the digestive tract is not 100% efficient. The portion
remaining is used for maintenance, growth or
fattening, milk production in the case of a brood
mare