Cutting calories is essential for weight loss but this shouldn’t come at the expense of providing a balanced diet. Lysine is an essential amino acid and is one of several nutrients that may be deficient in a calorie restricted diet. After a quick glance at your feed bag, you may have come across the words ‘amino acids’ or ‘lysine’ but if you are unsure about what they really mean and why they are important for your horse you’re probably not alone.

overweight ponies grazing needing more lysine

Protein & amino acid basics

The body contains thousands of different proteins, most of which are found in muscle tissue (although protein is a key component of all body cells including skin and blood). Proteins are made up of ‘building blocks’ called amino acids.  There are 21 amino acids in total, 9 of which are called ‘essential’ because they can’t be produced by the body and must be supplied by the diet. Lysine is an essential amino acid and the amino acid most likely to be deficient in a horse’s diet.  Dietary protein is broken down into amino acids and rebuilt (protein synthesis) to form proteins that are needed by the body. For protein synthesis to occur, amino acids need to present at a specific ratio. If one amino acid is deficient, protein synthesis is limited, even if all other amino acids are over-supplied.

Lysine and calorie restricted diets

Cutting back on calories may lead to the diet falling short of essential nutrients, including lysine. The aim of dieting (for horses and humans) is to lose fat but inevitably, some of the weight lost will be muscle. However, this will be exacerbated if protein and amino acid requirements are not met as the body will begin to break down muscle tissue to try and meet protein and energy demand.

hay soaking



Balancers are the ideal way to provide good doers with essential vitamins, minerals and amino acids while adding minimal calories, starch and sugar to the diet. Contrary to popular belief, ‘lite’ balancers are not significantly lower in calories than regular balancers but they may have other benefits to offer. SPILLERS Lite & Lean Balancer is specifically formulated to balance a calorie restricted diet, including high levels of lysine and vitamin E (vitamin E is considered the most important antioxidant and may also be deficient in calorie restricted diets). It also includes added cinnamon and FOS to help support a healthy metabolism.

For more advice on feeding your good doer contact the SPILLERS Care-Line.


Popular Blogs