Protein for Equine Health and Performance

Protein For Your Horse’s Health and Performance

Protein is probably one of the most misunderstood nutrients in the horse’s diet. Often thought of as an energy source, protein mainly provides structure along with other key functions within the horse’s body.  Protein is vital for correct body function and muscle integrity, so it is important to know how much your horse needs for optimal health and performance. In this blog we explain the basics of protein and how you can ensure your horse is getting enough, whatever their lifestyle:

What is Protein?

All tissues in the body are made of protein, along with enzymes, hormones, and antibodies. Protein is a major body constituent and is present in hooves, skin, hair, and muscle, making up around 15% of the horse’s body mass. A major function of protein is repairing and building muscles, tendons, and ligaments, so it is vital for optimum performance, no matter what level and type of work your horse does.

Protein is made up of chains of amino acids – the ‘Building Blocks’ of protein, so the horses’ individual requirement is, essentially, for amino acids. There are 21 amino acids that are a part of protein in mammals like horses, and 10 of these are known as ‘essential’, with lysine considered to be the most critical. These ‘essential’ amino acids need to be provided in the diet as the horse either cannot synthesise them at all or in large enough quantities to meet demand.

When your horse consumes protein, it is broken down in the small intestine by enzymes called proteases. The proteases break down the long chain of amino acids into individual amino acids which are then released and absorbed into the bloodstream. The amino acids are then re-synthesised into protein as needed for maintenance, growth, and repair, for example to repair muscle mass damaged during harder work performance. However, this is not an efficient process, resulting in protein losses and a continual need for dietary protein to replace them.

Not All Proteins Are Created Equal

Many different proteins can be synthesised according to different combinations of amino acids in the chain, but all the required amino acids need to be present at the same time to make a specific protein. Certain amino acids, however, always need to be present to build protein or synthesis is limited and these are known as ‘limiting’ amino acids, namely, Lysine, Threonine and Methionine. Lysine is the first limiting amino acid as its supply normally runs out first, so it is important that dietary protein contains good levels of lysine but also adequate levels of threonine and methionine for correct protein synthesis.

Quality is Key

Dietary protein quality is defined by how well it is digested in the small intestine and by how closely the individual proportions of amino acids contained within match the proportions required by your horse’s tissues. Overall protein quality is greatly improved by good levels of lysine.

The protein content of feeds is expressed as Crude Protein (CP) because there is no Digestible Protein (DP) clarification for horses, making it difficult to know how much protein is well digested. As a general guide, the actual DP of a feed is currently estimated to be about 2-5% less than the CP stated, but the higher the quality of the protein the better its digestibility will be.

Protein Sources

Good sources of dietary protein for your horse or pony, include:

• Fresh Grass, chop, or pellets
• Good-quality hay and haylage
• High specification Balancers
• Copra Meal
• Linseed meal
• Peas
• Chia seeds

 How Much Protein Does Your Horse need?

Protein requirements, in line with the protein content of feeds, are also expressed as CP. In general, to fulfil protein requirements, horses need around 8-12% protein according to type and workload, but this can be higher, for example, for foals and lactating mares. The table below gives a guide of the percentage of daily protein required by different classes of horses:

Table 1. Daily % Protein recommendations for different types of horses

Classification	Protein Level %
Nursing foal, 2-4 months (needs above milk)	16
Weanling at 4 months	14.5
Weanling at 6 months	14.5
Yearling (12 months)	12.5
2 year old (24 months)	11
Mature horse maintenance (idle)	8
Mature horse in light work (e.g. pleasure riding)	10
Mature horse in moderate work (e.g. jumping)	10.5
Mature horse in intense work (e.g. racing, polo, endurance)	11.5
Elderly horse	12
Stallion in breeding season	10
Pregnant mare – first nine months	8
Pregnant mare – 9th and 10th months	10
Pregnant mare – 11th month	11
Lactating mare – first 3 months	13
Lactating mare – from 3rd month on	11

These figures consider the protein needed within the whole diet, not just from certain feed. Therefore, protein levels in an individual feed should be considered within the wider context of the overall diet, to help provide the right levels of protein needed according to lifestyle.  It’s easy to get consumed by protein levels in individual feed but it’s the forage that will be providing the highest levels of protein due to the amount consumed daily.

It is also important to understand that whilst feeds like Copra meal may have a higher crude protein content, this means they contain higher quality protein, which is well digested, and therefore, would not be a problem for a healthy horse.

Too Much Protein?

Too much protein in the diet is often blamed for a multitude of problems but this is a myth. Concerns around protein have arisen where protein content was listed on a bag of feed and starch and sugar were not. Historically, feeds higher in protein would be higher in starch and sugar too (even though there are now many exceptions to that rule like Copra meal which is typically low in starch and sugar), but because only the protein was listed, this was then blamed as the cause of any problems.

Some of the diseases and problems that protein is wrongly blamed for include:

• Laminitis – most laminitis cases result due to an underlying problem like EMS or PPID. Horses prone to laminitis need to have the amount of sugar and starch in the ration restricted, not the amount of protein.
• Muscle problems – research has shown that it is high-starch diets, not excessive protein intake which is a contributing factor to muscle-related problems.
• Over-excitable behaviour – this is one of the biggest and most incorrect feeding myths around. Protein can be used as an energy source, but this is normally only when the horse is not receiving enough energy from the diet. Thus, excitable, or ‘fizzy’ behaviour is more likely to be caused by an increase in energy intake, which an owner might not be aware of. The levels of energy in grass and hay or haylage can vary throughout the year so, even if the horse eats the same amount of forage, the energy intake might still increase through ‘hidden’ energy.

Protein fed in excess of requirement results in 2 waste products: Urea and Ammonia, which then have to be excreted via the kidneys. Ammonia produces a strong smell after exiting the body in urine and can often be smelt in the stable if your horse is receiving too much protein. Ammonia in the stable can also cause irritation to the respiratory tract, which could compromise your horse’s performance.

The process of excreting urea and ammonia results in an increase in urine output which can put a strain on the kidneys, and consequently your horse will have an increased need for water. Therefore, it’s best to avoid feeding too much protein because of the potential to cause certain health problems. Instead, look for feeds like Copra meal that provide good quality protein that is well digested.

Top Tips For Supplying Protein:

• Feed the best quality protein you can by providing a nutritious diet, which includes good sources of protein.
• Look for feeds containing good levels of Lysine and ideally, Methionine and Threonine, like CoolStance Copra which indicates good protein quality.
• Feeds like CoolStance Copra that also provide an excellent profile of key essential amino acids from Lysine and Methionine, through to Leucine and arginine can further boost protein supply.
• Consider your horse’s work levels to deliver the right amount of protein for peak health and performance.

If you have any questions about creating the best diet for your horse or pony and keeping your horse healthy through the right nutrition, please contact 01488 73322 or info@boomerangnutrition.co.uk.