Protein is required in the horse’s daily diet to facilitate good overall health and to maintain and build muscle. Many horse owners mistakenly believe that the more protein they feed their equine athletes the better the horse will perform as the process of muscle development (hypertrophy) will be enhanced. This is not the case and feeding more protein can be a negative component in the development of the horse’s physique and wellbeing. Muscle mass can only be built through eating adequate amounts of quality protein and through exercise.
Protein is composed of chains of amino acids, and these amino acids are the building blocks for bone, muscle, cartilage, skin and immune cells. However, feeding more protein isn’t necessarily the answer for overall horse health.
The body does not store protein the way it does fat and glucose. When a horse is fed excess protein, the horse’s liver and kidneys must breakdown the excess protein and then remove it from the system. Thus constant overfeeding of protein will stress these organs. It is imperative that excess protein is removed from blood and tissues, as otherwise its presence can cause other health issues such as insulin resistance and affect bone metabolism.
As the horse’s body must work hard to eliminate the excess protein and this can create more heat and sweating in the horse in addition to stressing organs causing them to function less effectively. The use of energy to break down excess protein could be much better utilized elsewhere to improve overall performance and health of the horse.
When it comes to horse feeds it is important to note that not all protein is created equal and the specific amino acid profile of each ingredient varies. Each profile provides different amino acids to the horse, some are essential and others are non-essential.
Therefore, it is not the amount of protein in the diet that is most important, but rather the quality of the protein that is given. Better quality proteins with a variety of optimal amino acid profiles offer more availability for the horse to utilise which translates into the horse’s body not being taxed to eliminate excessive protein in its diet. Additionally, increased excretion of urea (the end product of protein breakdown), can form ammonia in the horse’s environment and cause issues with pollution in the soil and waters in the surrounding habitat as well as respiratory issues for the horse if kept in a poorly ventilated stall.