Public Consultation of the Working Document on the "Guidance for the assessment of compatibility of zootechnical microbial additives with antimicrobial substances"

Products containing one or more strains of viable micro-organisms are commonly authorised as zootechnical additives under Regulation (EC) No 1831/2003, on additives for use in animal nutrition. Such microbial additives are normally intended to improve animal performance or produce welfare benefits. At the same time, there are other several products authorised as feed additives that show an antimicrobial activity.

When a microbial additive is introduced in a feed containing an additive showing antimicrobial activity, the latter may impair the activity of the microbial additive. Therefore, it is necessary to establish the compatibility between the two additives to ensure that no incompatibility will happen when used simultaneously.

At present, there is no consistency in the data presented to establish compatibility between additives within the digestive tract of livestock, some applicants basing their studies on in vivo trials while others rely on in vitro data.

EFSA and the FEEDAP Panel decided to consult interested parties before the final adoption of this document. The outcome of this consultation will be considered during the final discussion of this document by EFSA’s FEEDAP Panel.