Getting your horses energy intake and output in balance is a bit of a gamble – You dont want him bouncing before a competition, yet you dont want him flagging near the finish. So how do you get the balance right? Below is a guide. All about energy, feed, input and output!
But, What is Energy?
Energy is a word that is used so lightly, and everyone uses it, but what is energy?
That is not an easy question to answer. Energy can be perceived as many things, but in this case, energy is the food’s potential to fuel bodily functions. Everything your horse eats gives calories (energy) and everything he does uses it. Fat offers the richest kilocalorie density per gram (kcal/g), twice that of protein, and four times more than carbohydrate.
The fuel is absorbed from the digestive tract as glucose, an energy rich simple sugar. It is used for respiration, a process which occurs inside the body cells, in organelles known as the mitochondria. But it can’t float around the blood all day, it has to be stored somewhere! It is converted into a structural carbohydrate called glycogen in the liver, and to a lesser extent, in the muscles. But there is a limit to how much the liver can hold, (only about 100g) and the rest has to somewhere. So it is turned into triglycerides (fat) and stored on the muscles, and in the ”podgy bits”, areas of adipose tissue.
Muscles are fueled by adenosine tri-phosphate (ATP), an energy unit which cannot be stored. It consists of an adenine molecule, and two permanent phosphate bonds. The third is an energy rich bond which gives instant oomph. ATP is made in two ways. With, or without oxygen. When your horse is doing low intensity work such as walking or trotting, glucose and oxygen are subjected to powerful and complex reactions which create an energy bond to bind the third phosphate to adenosine di-phosphate, or ADP, to create ATP. With plenty of oxygen, up to 36 ATPs can be produced from a single glucose molecule.
When a horse is fleeing from an extremely dangerous plastic bag (!), the oxygen demand cannot be met, so anaerobic glycolysis is used instead. This is a short term, quick fix, that only yields 3 ATPs!
Fact! Did you know… To maintain his weight, a 450 kg horse needs to consume 15,000 calories per day! This is a huge number, and (for a human) would mean eating 115 weetabix per day!!
Tip! Get your horse fit. Believe it, or not, it improves his feed utilization!
Tip! Don’t over estimate your horses workload! Most horses are only in light, perhaps medium work…
The energy Sources
Protein, fat, carbohydrates and fibre are all energy souces. Fat provides high energy, however it is slow release, and soes not break down fast enough for ‘instant’ explosive energy. Starch and sugar givves a quick burst of energy that can be difficult to manage, while protein is an inefficient source, and too much used for energy causes tissue repair negligence. Fibre provides slow release energy, and is an essential part in all horse’s diets.
How much energy Does a horse need?
A 500kg horse in hard work – ridden 6 days a week and competing most weekends needs 33,000 calories just to maintain his weight! This is equivalent to eating 60kgs of grass per day!
A horse on rest needs about 15,000 calories just to maintain his weight!
A horse in hard work has a high metabolic rate, and therefore produces more free radicals. These are damaging waste products that can cause DNA mutation that can lead to cancer. Feeding a vitamin E or C supplement will help neutralize these.
Fat contains 10 times the amount of energy over protein carbohydrate and fibre, however, it is very slow-release. If your horse is an eventer or racer, highly digestible energy in carbohydrate form is usually best, while endurance horses work aerobically most of the time, and benefit from a higher fat ration in the diet.