What is sepiolite?
Sepiolite is a magnesium-rich clay mineral. Unlike montmorillonite, which is built from flat, stacked layers, sepiolite forms fibres: ribbons of silicate sheets arranged so that long, narrow channels run along each fibre. These channels hold water, and together with the fibrous shape they give the mineral a high surface area and a strong capacity to absorb liquids.
Because of this structure sepiolite does not swell much in water, but it forms stable gels and suspensions, holds oils and other liquids well and keeps powders flowing. Türkiye is a known sepiolite source; the Eskişehir region is well known for sepiolite, including the compact variety traditionally carved as meerschaum.
What does it do in animal feed?
Sepiolite is used for its technological properties; it is not a nutrient source in practical terms.
- Pellet binder: helps hold particles together and supports pellet durability.
- Anti-caking and flow agent: reduces lumping in powdered feeds, mineral mixes and premixes.
- Carrier and absorbent: its absorption capacity allows liquid or sticky ingredients to be converted into free-flowing powders.
- Mixing support: as an inert, fine carrier it helps distribute micro-ingredients evenly.
- Toxin binder blends: it is sometimes combined with other clays, although its aflatoxin-binding capacity is generally considered lower than that of smectite-rich bentonite.
Sepiolite compared with bentonite
Both are clays, but their structures lead to different strengths. Bentonite's expandable montmorillonite layers make it the reference clay for aflatoxin binding and give strong swelling and binding. Sepiolite's fibrous, channelled structure gives it superior absorption of liquids and good flow and anti-caking performance. In practice, the choice depends on whether the main goal is mycotoxin binding, pellet quality, flowability or carrying liquids.
How is inclusion assessed?
There is no nutritional requirement for sepiolite. Its inclusion is set by the technological purpose: the amount needed for pellet binding, for flow, or to carry a given quantity of liquid. It must be used within the conditions that feed legislation sets for the authorised product. Because it is a natural mineral, the purity of the source and its contaminant profile are as important as its level in the feed. Local regulations and the product label always prevail.
Quality criteria for feed-grade sepiolite
- Sepiolite content and mineralogy: confirmed by X-ray diffraction (XRD); low levels of accompanying minerals such as quartz and carbonates.
- Absorption capacity: for example water or oil absorption, important when used as a carrier.
- Heavy metals and dioxins: within the undesirable-substance limits of feed legislation.
- Moisture and particle size: affect flow, mixing uniformity and dust.
- Microbiological quality: the product should be dry and free from contamination.
- Traceability: a certificate of analysis (CoA) and lot number for every batch.
CTF Premix and sepiolite
CTF Premix produces montmorillonite-based toxin binders and feed-grade bentonite at its 10,000 m² facility in Ankara under ISO 9001:2015 and GMP. Requests involving sepiolite, whether as a binder, carrier or component in a clay blend, are evaluated by our technical team according to the intended use. Every lot is traceable, and its certificate of analysis can be viewed on the batch verification page.
This page is for general information. Inclusion rates and product choice should be decided with a nutritionist, taking into account the species, the feed formulation and the applicable regulations.