Pea protein isolate is a relatively new product in South Africa, but as owners begin to see the impact of this powerful supplement, its popularity is increasing. Traditionally, horses have derived protein from sources like alfalfa, soy, and flax, but pea protein isolate (PPI) is emerging as a viable and perhaps better alternative. This article explores the benefits, limitations, and potential use cases for pea protein isolate in horse diets.
What is pea protein isolate?
Pea protein is derived from yellow split peas (Pisum sativum) through a process that removes starch and fibre, leaving a concentrated protein source. Pea protein isolate is the most refined form, containing up to 85-90% protein. It is rich in essential amino acids, particularly lysine, which is crucial for muscle development in horses.
Note
Not all pea protein supplements are created equal. Many of those on the South African market are made from pea protein flour, which is much lower in protein levels than true pea protein isolate. As with all supplements, read the ingredients and make sure you know what you are buying.
Nutritional benefits
Rich in essential amino acids
Protein quality in equine diets is determined by its amino acid profile. Pea protein isolate contains high levels of lysine, an essential amino acid often lacking in common feedstuffs like maise and oat hay. Lysine is critical for muscle repair, growth, and immune function.
What is an essential amino acid?
An essential amino acid is an amino acid that an organism cannot synthesise on its own in sufficient quantities and must obtain through its diet. In horses, essential amino acids include lysine, methionine, threonine, valine, leucine, isoleucine, histidine, phenylalanine, and tryptophan. These amino acids are crucial for muscle development, tissue repair, enzyme production, and overall metabolic function.
Lysine is often considered the most limiting essential amino acid in equine diets, meaning if it’s deficient, it can restrict protein synthesis even if other amino acids are available.
Hypoallergenic and easily digestible
Soy is a traditional high-protein feed ingredient, but some horses develop sensitivities to soy proteins. Pea protein isolate is naturally hypoallergenic, making it a suitable alternative for horses with dietary sensitivities or inflammatory conditions.
Environmentally sustainable
South Africa, like many regions, faces increasing pressure to adopt environmentally sustainable agricultural practices. Pea protein isolate production requires less water and generates lower carbon emissions than soy or animal-derived proteins, aligning with global sustainability goals.
Scientific research on pea protein isolate in horses
While extensive research on pea protein isolate in horses is limited, studies on other species suggest its efficacy. In a study published in the Journal of Animal Science (2021), researchers found that pea protein isolate provided similar muscle recovery benefits to whey protein in athletic animals. Another study in the British Journal of Nutrition (2020) reported that pea protein isolate effectively supported muscle maintenance in ageing mammals, suggesting potential benefits for senior horses.
How can pea protein isolate be used in equine diets?
As a supplement for performance horses
Adequate protein intake is important for muscle growth, energy, hoof health, skin and coat quality and more. Performance horses have increased protein requirements due to muscle exertion. Feeding pea protein isolate can provide this protein and improve recovery from exercise, topline development and recovery from injury or illness.
As a protein source in balancer feeds
Feed manufacturers can incorporate pea protein isolate into formulated feeds for horses requiring a non-soy protein option. Given its high lysine content, it can help balance diets based on cereal grains.
For senior horses and those with metabolic issues
Older horses and those with metabolic conditions, such as insulin resistance, benefit from high-quality protein sources that do not contribute to excessive sugar intake. Pea protein isolate provides essential amino acids without unnecessary carbohydrates.
For horses with higher protein requirements
Protein requirements are higher for pregnant and lactating mares, as well as growing horses; pea protein isolate can assist in providing the higher protein levels required.
Note
Only add supplements in consultation with an equine nutritionist or your vet. The above list includes general use cases, but each horse and situation must be assessed by a professional before changing the diet.
Potential limitations and considerations
Methionine deficiency
Although pea protein isolate is rich in lysine, it is relatively low in methionine, another essential amino acid important for hoof health and coat condition. Supplementing with methionine or combining pea protein isolate with other protein sources, such as flax or alfalfa, can help balance amino acid intake.
Palatability
Some horses may take time to adjust to the taste of pea protein isolate. Mixing it with molasses-free chaff or a preferred feed can improve acceptance.
Suitability
For horses with liver and kidney disease high levels of protein can be harmful so for horses suffering from either of these conditions, pea protein isolate is not an appropriate supplement.
Conclusion
Pea protein isolate presents an exciting alternative for equine nutrition, particularly for South African horse owners seeking sustainable, high-quality protein sources. While further equine-specific research is needed, existing studies in other species indicate promising benefits. Whether used as a supplement for performance horses, a component in balancer feeds, or a protein source for senior horses, pea protein isolate has the potential to contribute positively to equine health and nutrition. As the industry continues to evolve, embracing plant-based protein sources like pea protein isolate may be a step toward more sustainable and effective horse-feeding practices.