Proficiency of official control European laboratories in the determination of authorised coccidiostats in poultry feed : EURL Feed Additives Control PT exercise 2013 Cross-contamination level

The European Union Reference Laboratory for Feed additives (EURL-FA), has been mandated by the Directorate General for Health and Consumers (DG SANCO) to organise a proficiency test (PT) among appointed National Reference Laboratories (NRLs). The aim of the PT was to assess the capacity of the NRLs to correctly determine 11 authorised coccidiostats in feed matrices. This report presents the results of the PT. Thirty-two laboratories from 22 countries registered to this 2013 PT exercise. Laboratory results were rated using z- and ζ-scores (zeta-scores). Between 64 % and 80 % of the laboratories reported satisfactory results for monensin, narasin, nicarbazin and maduramicin. For lasalocid, only 59 % of the laboratories submitted satisfactory results, 58 % for diclazuril and 53 % for halofuginone. The laboratories also reported qualitative results as regards the presence of one or more of the other authorised coccidiostats. On the whole, the rate of false positive results was 6 % for lasalocid, 4 % for maduramicin, 5 % for halofuginone, 3 % for robenidine and 0 % for all the others.