European union reference laboratory for feed additives: experience from 11 years organising proficiency testing

Abstract

Feed additives are individually authorised within the European Union (EU) specifying the conditions of their use under real-world conditions. These criteria often include minimum or maximum level of their content in compound feed. In addition, feed business operators are obliged to indicate on the feed the level of the added content of the feed additive. While it is the task of the EU Member States official laboratories to perform control analyses to establish compliance with these provisions, the European Union Reference Laboratory for Feed Additives (EURL-FA) is organising since 2012 annual proficiency tests (PTs) for Member States’ National Reference Laboratories (NRLs). PTs organised by the EURL-FA are based on the principles that compound feed samples are prepared containing a known content of the target feed additive. These PT samples are then sent to the NRLs for analysis and the results reported back to the EURL-FA are subjected to statistical assessment to establish the laboratory specific proficiency to correctly analyse compound feed samples for the respective feed additive. In the current study, we looked at the outcome of this assessment across different PTs. The topics addressed were (1) the evaluation of the overall measurement capability of NRLs in respect to coccidiostats, trace elements and vitamin D3, (2) the challenge related to the preparation of homogenous test materials with particle-based feed additives, (3) a possible connection between the modified composition of preparations containing vitamin A and analytical results and (4) the impact of a training course on the proficiency of laboratories regarding carotenoid analysis.

Keywords

• feed additive analysis
• proficiency tests