Duddingtonia flagrans in feed: what changes for livestock farmers and manufacturers in 2026

Key data

European livestock farmers have from 1 April 2026 a new authorized tool to reduce parasite burden in their herds without relying exclusively on chemical antiparasitics. The Commission Implementing Regulation (EU) 2026/534, published on 12 March 2026, authorizes the use of the preparation of Duddingtonia flagrans NCIMB 30336 as an additive in feed for grazing animals of multiple species throughout the EU.

The authorization is not automatic or universal: it expressly excludes animals intended for milk production and requires feed manufacturers to comply with specific conditions of use, dosage and labeling before marketing any product incorporating this additive.

What does this regulation establish?

The regulation formally authorizes the use of the nematophagous fungus Duddingtonia flagrans NCIMB 30336 as an additive in feed for grazing animals. This fungus acts by destroying the infective larvae of parasitic nematodes present in pastures, which reduces the parasite burden to which livestock is exposed.

The authorization establishes three blocks of obligations for industry operators:

• Specific conditions of use: The regulation sets the parameters under which the additive can be incorporated into feed.
• Authorized dosages: Manufacturers must respect the dosage levels established in the regulatory text.
• Labeling requirements: Feed containing this additive must be labeled in accordance with the regulation's requirements.

The authorization is valid throughout the European Union and applies exclusively to the species and categories of animals detailed below.

Economic and operational impact

This authorization has two readings depending on the type of operator:

For feed manufacturers: It represents an opportunity to expand their catalog with formulations incorporating biological parasite control, but implies an investment in process adaptation, technical documentation and labeling. It is not a mandatory change, but a new product possibility that requires compliance with the regulation's requirements if it is to be marketed.

For farmers: The authorization opens the door to reducing the use of conventional chemical antiparasitics, with the consequent impact on treatment costs, parasite resistance and positioning in markets that value sustainable production. Beef cattle, sheep and goat farmers are the primary direct beneficiaries, as those intended for dairy production are excluded.

The immediate operational impact falls on feed manufacturers, who must adapt their formulations and technical documentation if they wish to incorporate this additive before marketing it. Failing to do so and marketing the product without complying with the regulation's requirements means operating outside the European legal framework for feed additives.

Who does it affect?

• Feed manufacturers: Must adapt formulations, technical documentation and labeling if they incorporate the additive Duddingtonia flagrans NCIMB 30336 in their products.
• Beef cattle farmers: Can benefit from feed with biological control of parasitic nematodes from 1 April 2026.
• Beef sheep and goat farmers: Same situation as beef cattle; excluded if their animals produce milk.
• Equine farmers: Included in the authorization for grazing animals.
• Camelid and cervid farmers: Included in the authorization.
• Grazing pig and rabbit farmers: Included in the authorization.
• Dairy cattle, sheep and goat farmers: Expressly excluded from the authorization.
• Distributors and animal nutrition technical advisors: Must know the regulation to correctly inform their clients about the possibilities and limitations of the additive.

Practical example

A feed manufacturing company that works with beef cattle and sheep farmers in Spain wants to launch a new line of feed with biological parasite control by incorporating Duddingtonia flagrans NCIMB 30336.

From 1 April 2026, this company can do so legally if it complies with the three requirements of Regulation (EU) 2026/534: respecting the conditions of use and dosages established, and correctly labeling the feed. Before launching the product, it will need to review and update its technical documentation in accordance with the regulation.

If that same company also has dairy cattle or dairy sheep farmer clients, it cannot include this additive in feed intended for those animals: the exclusion is express for those intended for milk production, regardless of species.

The beef cattle farmer who adopts this feed can reduce parasite pressure in their pastures without relying solely on chemical antiparasitic treatments, which can result in lower treatment costs and a competitive advantage in markets that value sustainable production.

What should companies do now?

1. Assess whether the additive is relevant to your product portfolio or operation: Determine if you manufacture feed or have livestock of the authorized species (cattle, sheep, goats, camelids, cervids, equines, pigs or grazing rabbits) and whether they are excluded from dairy production.
2. Review the full text of Regulation (EU) 2026/534: Consult the specific conditions of use, authorized dosage levels and labeling requirements before making any formulation or purchase decision.
3. Adapt technical documentation: If you are a feed manufacturer and decide to incorporate this additive, update your technical sheets, formulation records and labels in accordance with the regulation's requirements before 1 April 2026 or before marketing the product.
4. Contact the authorization holder's representative in the EU: For technical and commercial information about the NCIMB 30336 preparation, the contact point in the EU is SynTech Regulatory Europe GmbH.