This article has not yet been professionally approved. The information is based on the sources listed below.
Standard mineral feed or filling the gaps?
A standard mineral feed has to guess what is missing from your ration. We calculate instead – and only release selenium and iodine once a lab value is available.
Mineral feed is the best-selling category on the complementary feed shelf – and the one where a standard product can achieve the least. That is why we do not carry a universal mineral feed. This is not a gap in our range but a decision we want to justify.
The reason is simple: a mineral feed is meant to close the gaps in a ration. If you do not know the ration, you do not know the gaps – and you end up supplementing according to the average rather than to requirements. Hay, however, varies considerably from batch to batch, and what a horse already takes in through muesli, lick or pasture is not printed on any packet 12.
So the difference is not that we would not supplement minerals. The difference is that, with us, each individual substance only goes into the mix once the calculation calls for it – and the critical ones only once a measurement confirms it.
What an honest mineral feed requires
Requirement values for macrominerals and trace elements are well researched and tabulated 134. The problem is not on the requirement side but on the intake side: without a hay analysis, the second half of the calculation is unknown.
A standard mineral feed solves this by assuming a typical average. For many horses, it is roughly right. For those where it is off, nobody notices – neither oversupply nor undersupply hurts in the short term.
The four substances that decide it
Four substances decide whether a complementary feed can manage with or without knowledge of the ration. What specifically happens when they are oversupplied is described in detail in the article “When trace elements become too much”.
| Substance | Why it is tricky without knowing the ration | How we solve it |
|---|---|---|
| Selenium | The narrowest safety margin in horse feed: there is little between maintenance requirement and toxicity, and the legal total maximum content of 0.5 mg/kg complete feed applies across all sources combined 15. | A separate module that is only unlocked after a reliable selenium lab value. Without an analysis, no selenium goes into the automatically assembled pack. |
| Iodine | A narrow window in both directions – too little and too much both disrupt thyroid hormone synthesis. For equines, a maximum content of 4 mg/kg complete feed applies, with 3 mg/kg recommended 136. | Also a separate module requiring a lab value – the same logic as for selenium. |
| Iron | Deficiency is rare in adult horses; basic rations usually supply plenty. Additional iron competes with copper and zinc for absorption and is hardly excretable 73. Our ration check does not store a legal maximum content as a limit for iron, and iron is never supplemented automatically. | Not included in any of our modules. |
| Vitamin A and D3 | Fat-soluble and stored in the body. A high dose brings no additional benefit but worsens the safety profile 31. | Also not included. Vitamin E, on the other hand, we offer as a separate module – its content falls predictably in preserved forage, which makes it a calculable gap. |
What a standard mineral feed supplies blindly – and how we handle it instead.
What this means for our modules
Instead of a universal product, an individual formula is created for exactly one horse, into which each substance is only included if the calculation shows a gap: calcium, phosphorus and magnesium, zinc and copper in a balanced ratio, vitamin E, sodium and chloride – and selenium and iodine only behind the lab gate.
Two design principles keep this safe. First, each trace element appears in exactly one module, so that no combination of modules shifts the ratios – zinc and copper are deliberately in the same building block because they share absorption pathways. Second, the catalogue has no way at all of supplying selenium or iodine without an analysis: if the lab value is missing, the module drops out of the recommendation, even if the calculation shows a gap.
Exactly one question remains open – whether your horse is already getting a mineral feed. We ask it in the ration plan rather than ignoring it.
If you decide on a standard product
This decision is legitimate – it is the pragmatic route as long as no hay analysis is available. What matters then is choosing the product deliberately and offsetting the intake from all sources. What to look out for is explained in the article “Mineral feed for horses: check requirements and choice”.
Sources & studies
The content is based on the references listed below. It does not replace individual veterinary or feeding advice.
Show list of sources (8)
- GfE (2014) – Empfehlungen zur Energie- und Nährstoffversorgung von PferdenSpecialist reference in German-speaking countries (GfE, German Society of Nutrition Physiology), Committee for Requirement Standards
- 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)
- NRC – Nutrient Requirements of Horses, 6th ed.International reference for the nutrient requirements of horses (National Research Council)
- 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)
- Durchführungsverordnung (EU) 2020/2117Renewal of the authorisation of selenium yeast from Saccharomyces cerevisiae CNCM I-3399 (identification number 3b812) for all animal species; total maximum content of selenium 0.50 mg/kg complete feed (12% moisture) and at most 0.2 mg/kg of added organic selenium. Authorisation expires according to the Annex on 6 January 2031. Other selenium sources with the same total value: Implementing Regulations (EU) 2019/49, 2019/804 and 2024/3168.
- Durchführungsverordnung (EU) 2015/861Authorisation of potassium iodide, anhydrous calcium iodate and coated granulated calcium iodate (identification numbers 3b201 to 3b203); total maximum content of iodine for equids 4 mg/kg complete feed (12% moisture). Under other provisions, the Annex additionally gives a recommended maximum content of 3 mg/kg (not the binding value). Authorisation expires according to the Annex on 24 June 2025; for the renewal procedure see the EFSA opinion. According to the EU Register of Feed Additives (as of 15 October 2026), an application for renewal under Art. 14 of Regulation (EC) No 1831/2003 has been submitted; the authorisation remains valid.
- Merck Veterinary Manual: Nutritional Diseases of Horses (Eisen)Iron deficiency is rare in adult horses; forage practically always supplies plenty of iron, and supplementation is only indicated where there is a specific reason
- Verordnung (EG) Nr. 1831/2003Feed additives – authorisation and use; “daily ration” based on 12% moisture (Art. 2(2)(f)), renewal of authorisation and automatic continuation (Art. 14(4)), general conditions of use (Annex IV: natural plus added amount; complementary feed, diluted as specified, at most at the level for complete feed). Link to the current EUR-Lex consolidated version (as of 27 March 2021).