This article has not yet been professionally approved. The information is based on the sources listed below.
Natural mineral feed: what “natural” and “organic” mean
What lies behind natural mineral feed, organically bound trace elements and herbal mixes, where the form really matters and why the amount is more important than the origin.
The short answer
A mineral remains the same substance, whether it comes from plants or from an authorised compound. Organically bound means the trace element is bound to amino acids, for example; these forms are also additives with the same maximum levels 12. Where the form clearly matters is vitamin E: the natural form is used better 3. What remains decisive is the amount, matched to the hay.
What “natural” means for minerals
Minerals are chemical elements such as calcium, zinc or copper. A zinc atom from a plant and one from an authorised compound are the same element in the body. Differences lie in the compound in which it is present, and therefore in solubility and absorption.
The most natural source is forage. Hay and grass supply most of the macrominerals, but their content depends on soil, plant population and cut 4. A hay analysis shows what is lacking.
Organically or inorganically bound
Inorganic forms are, for example, zinc oxide or copper sulphate. Organically bound forms, often referred to as chelates, bind the trace element to amino acids or similar molecules. Both groups are additives that must be authorised throughout the EU 12.
The maximum levels apply to the element, not the compound. 120 mg of zinc per kg of complete feed is the limit, whether as oxide or chelate 2. Better absorption would therefore be a reason to dose rather less, not more.
Where the form really matters: vitamin E
For vitamin E, the difference is well documented. The natural form RRR-α-tocopherol (often declared as “d”) is used more effectively by the horse than the synthetic all-rac form (“dl”) 3. 1,000 IU of natural vitamin E corresponds roughly to 1,340 IU of the synthetic form 5.
Herbal and plant mixes
Mixes of herbs, leaves and bark supply minerals, but in amounts that vary from batch to batch. Without an analysis, you do not know how much zinc, copper or selenium your horse gets from them.
If you deliberately want to feed naturally, you can do so and still calculate: hay values and a known supplement show whether the ration fits. Feeding without reference to requirements risks both gaps and excesses 6.
Key takeaways
Frequently asked questions
Are organically bound minerals better?
For horses, a clinical advantage is hardly documented. The only controlled study on zinc methionine and the hoof includes seven horses and shows denser horn material, but no clinical endpoints 8. It is more important that the amount suits the ration.
What are chelates in mineral feed?
Chelates are compounds in which a trace element such as zinc or copper is bound to amino acids or similar molecules. They are listed as authorised forms in the EU regulations on trace elements 2. In the labelling, they appear under the additives 7.
Is a herbal mix enough instead of mineral feed?
Herbs and leaves contain minerals, but in variable amounts that are unknown without analysis. Whether such a mix closes the gaps in your hay can only be checked with values. Without values, it remains an assumption.
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)
- 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).
- Durchführungsverordnung (EU) 2016/1095Authorisation of zinc acetate, zinc chloride, zinc oxide, zinc sulphate and zinc chelates (3b601 ff.); total maximum content of zinc 120 mg/kg complete feed (12% moisture) for “other species and categories”, in which horses are not listed separately. Consolidated version of 25 September 2022 (including Implementing Regulation (EU) 2022/1458); authorisation expires according to the Annex on 27 July 2026; renewal procedures are under way at EFSA. 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 (checked for zinc acetate dihydrate, 3b601); the authorisation remains valid. Additionally Implementing Regulation (EU) 2024/265 (zinc(II) betaine complex, 120 for other species).
- Finno CJ, Valberg SJ (2012): A Comparative Review of Vitamin E and Associated Equine Disorders. Journal of Veterinary Internal Medicine 26(6):1251–1266Peer-reviewed review (PMID 22925200): structure, absorption and metabolism of vitamin E in horses, higher bioavailability of the natural (RRR) form, antioxidant function during exercise, need for supplementation with little access to pasture, and the neuromuscular diseases associated with persistent vitamin E deficiency (incl. eNAD/EDM, EMND, vitamin E-responsive myopathy).
- 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)
- Merck Veterinary Manual: Nutritional Requirements of Horses and Other EquidsSummary of the NRC recommendations: water requirement 5 litres per 100 kg body mass per day at maintenance, sweat losses of around 3.1 g sodium, 5.3 g chloride and 1.6 g potassium per litre, salt recommendation 1.6–1.8 g per kg feed dry matter at a maximum of 6% of the ration; from a 50% forage share potassium is adequately covered. Also covers the selenium requirement (0.1 mg/kg feed dry matter or at least 1 mg/day for a 500 kg horse, selenium as a component of glutathione peroxidase together with vitamin E) and the strong location-dependent variation of selenium in forage (grass forage on average 0.194 ppm, range 0–1.2 ppm); some regions are markedly low in selenium and may need supplementation. Also gives the iodine requirement (0.35 mg/kg feed dry matter, mares in late pregnancy 0.4), iodine poisoning of pregnant mares from around 40 mg/day, documented goitre cases in mares and their foals associated with large amounts of dried seaweed (kelp), that iodised salt easily covers the requirement, and that iodine supplementation is usually unnecessary except in severely iodine-deficient regions
- NRC – Nutrient Requirements of Horses, 6th ed.International reference for the nutrient requirements of horses (National Research Council)
- Verordnung (EG) Nr. 767/2009Placing on the market and use of feed, labelling and claims; definitions of complete feed (Art. 3(2)(i)) and complementary feed (point (j)), content of feed additives (Art. 8), feeding instructions (Annex II No. 4). Link to the current EUR-Lex consolidated version (as of 26 December 2018).
- Neri Basurto R, et al. (2008): Effect of zinc methionine on the equine hoof – an evaluation by environmental scanning electron microscopy. Veterinaria México 39(3):247–2537 horses, 5.4 g zinc methionine daily for 6 months: denser tubular and intertubular horn, more zinc and sulphur in the horn. Very small number of animals, no clinical endpoints – weak evidence