This article has not yet been professionally approved. The information is based on the sources listed below.
Soya bean meal for horses: supplementing protein in a targeted way
Extracted soya bean meal is a classic protein source with plenty of lysine. When protein supplementation is necessary at all, why the amount comes from the calculation and what to look out for regarding quality and competitions.
The short answer
Extracted soya bean meal is a protein feed with plenty of essential amino acids; when heat-treated, it is highly digestible and palatable 1. It only makes sense if the ration supplies too little digestible protein or lysine, for example with late-cut hay. There is no fixed amount: the Gruber Table (a German feed value table) bases the amount on performance requirements.
What soya bean meal supplies
Extracted soya bean meal is produced during oil extraction. Soya feeds are protein feeds and rich in essential amino acids. When heat-treated, i.e. toasted, flaked or as extracted meal, they are highly digestible and palatable 1.
Among the amino acids, lysine in particular is quantitatively well documented in horses; in the trials from which this evidence comes, lysine was often supplemented via soya bean meal 2.
Does your horse need more protein at all?
Grass hay usually covers the maintenance protein requirement of adult horses. Supply becomes tight mainly with late, stalky hay, with hard work, during growth and in lactation 34. Excess protein is not stored but broken down and excreted 3.
- Have the hay analysed, or at least know the cutting date and growth stage
- Derive the protein requirement from weight, work and life stage
- Balance digestible protein and lysine in the ration
- Only supplement the gap
Soya bean meal compared
| Feed | Classification | Note |
|---|---|---|
| Soya bean meal | Protein feed, rich in essential amino acids | Only heat-treated |
| Lucerne | Protein, lysine, a lot of calcium | Watch the Ca:P of the ration |
| Rapeseed meal | Protein feed, rich in essential amino acids | Only new, low-glucosinolate varieties |
| Dried brewer's yeast | Very high in protein | Relevant to doping rules from 150 g per day |
Qualitative classification according to the Gruber Table; contents vary by product 1.
Quality, changing over and competitions
Look for heat-treated products and impeccable feed hygiene 1. You should introduce new feeds gradually 5.
For competition horses: check every complementary feed against the current ADMR database (the German Equestrian Federation's anti-doping and medication database) before use 6.
Key takeaways
Frequently asked questions
How much soya bean meal does a horse need?
That depends on how large the protein gap is. The Gruber Table does not give a fixed amount but bases it on performance requirements 1. Calculate the ration first and then only add the missing amount of digestible protein.
Is soya bean meal good for building muscle?
Muscles develop through training with sufficient energy and protein supply. Soya bean meal can close a gap in protein and lysine; if the requirement is already covered, it does not lead to any additional muscle building 24.
Are there alternatives to soya?
Yes, for example lucerne, extracted rapeseed or sunflower meal and dried brewer's yeast. In terms of energy and protein, 1 kg of dried yeast corresponds to about 1 kg of extracted soya bean meal 1. For competition horses, dried brewer's yeast is relevant to doping rules from 150 g per day.
Sources & studies
The content is based on the references listed below. It does not replace individual veterinary or feeding advice.
Show list of sources (6)
- Bayerische Landesanstalt für Landwirtschaft (LfL): Gruber Tabelle zur PferdefütterungPractical reference table with requirement and feed values based on the GfE recommendations; the basis of many ration calculations in German-speaking countries. Chapter 9.3, Table 39: most common poisonous plants for horses with habitat, toxicity and risk level (after Kamphues et al. 2014)
- Mok CH, Urschel KL (2020): Amino acid requirements in horses (Invited Review). Asian-Australasian Journal of Animal Sciences 33(5):679–695Review of amino acid requirements: in horses essentially only lysine is quantitatively established; there are no robust requirement figures for methionine/threonine
- Coenen M, Vervuert I (2020): Pferdefütterung. Begründet von H. Meyer. 6., aktualisierte Aufl., Georg Thieme Verlag, Stuttgart. ISBN 978-3-13-241778-6Standard reference work on equine nutrition in German-speaking countries; Table 4.17 mineral recommendations (recommended supply and minimum requirement), Table 4.18 derived sweat volumes per work level and weight class, Table 4.19 electrolyte performance requirement per sweat volume (in addition to maintenance requirement)
- GfE (2014) – Empfehlungen zur Energie- und Nährstoffversorgung von PferdenSpecialist reference in German-speaking countries (GfE, German Society of Nutrition Physiology), Committee for Requirement Standards
- Liburt NR (2026): Feeding Practices in Horses and Other Equids. Merck Veterinary ManualSpecialist overview, as of February 2026: forage basis, concentrates as required, bran/mash and Ca:P balance, gradual feed changes. No efficacy study on commercial mash products.
- FN – Anti-Doping und Medikation (ADMR-Suchmaschine)Official database of the FN (German Equestrian Federation) on substances and withdrawal periods in competitive sport