Determination of processed animal proteins in feed: The performance characteristics of classical microscopy and immunoassay methods

Abstract

Species-specific detection and detection of groups of species such as ruminants is required according to European legislation dealing with the safe use of animal by-products in animal nutrition. Various methods are applied to the analysis of feed samples for the presence of banned processed animal proteins (PAPs) including meat and bone meal (MBM). Classical microscopy as described in the Commission Directive EC/2003/126 is the only official method to detect the presence of constituents of animal origin in feed, nevertheless some deviating protocols allowed under the old Directive (EC/88/1988) claim to gain comparable results. An inherent limitation of the microscopic method is the lack of species specificity. Immunoassays showed the most promising potential in research projects or intercomparison studies being able to detect ruminant PAPs at a concentration level of 0.5%. The aim of this paper is to present the results of the intercomparison study conducted on behalf of European Commission's Directorate General for Health and Consumer Protection (SANCO) in 2004 to establish whether the two-solvent method would gain comparable results to the current European Method and to evaluate the current capability of immunoassays of determining the species in PAPs present in feed.

Keywords:

• Animal feed
• bovine spongiform encephalopathy
• processed animal proteins (PAPs)
• meat-and-bone-meal (MBM)
• species identification
• microscopy
• immunoassays

Acknowledgments

The authors would like to thank the European Commission Direction General Health and Consumer Protection for financial support for this study.

The authors thank Isabelle Fissiaux, Felix Rwagasore and Olivier Fumière for the preparation and testing of the homogeneity of the samples.

In addition the authors are grateful to the following laboratories and institutes which participated in the intercomparison study: National Veterinary Institute (NVI), Slovenia; State Veterinary and Food Institute, Slovak Republic; Central control and testing institute of agriculture, Slovak Republic; Central Institute for supervising and testing in agriculture, Czech republick; State Veterinary Medicine Diagnostic Center, Latvia; National Veterinary Laboratory, Lithuania; Estonian Veterinary and Food Laboratory, Estonia; Central Veterinary Laboratory, Cyprus; Central Laboratory of National Institute for Agricultural Quality Control, Hungary; National Veterinary Research Institute, Poland; ZHW Szczecin, Poland; Landesanstalt für Landwirtschaft Thüringen, Germany; LUFA – Nordwest, Germany; LUFA – Speyer, Germany; LUFA – Augustenberg, Germany; Bayreisches Landesamt für Gesundheit und Lebensmittelsicherheit, Germany; Veterinary Laboratories Agency Luddington, UK; Seed Testing Station Abbotstown, Laboratory Compex, Ireland; EUROFINS – CRCB, France; Laboratoire DGCCRF de Rennes, France; Laboratoire Fédéral de l’alimentation/AFSCA, Belgium; LDA22, France; Neogen, US; ELISA Technologies, Inc., US; AntibodyShop A/S, Denmark; and Strategic Diagnostics Inc., US.