Identification of the presence of meat-bone meal derived from cattle in animal feed using three different commercial immunochemical tests

Abstract

Ban on use of meat-bone meal (MBM) in animal feed led to a significant reduction in the number of cases of bovine spongioformne encephalopathy (BSE). Currently, by Regulations of the European Union, the optical microscopy is recognized as the only reference method for the detection of processed animal proteins in animal feed. European legislation also anticipates that with conventional microscopy other laboratory tests can be applied, should they provide the ability to determine the origin of animal ingredients. For this reason, a variety of alternative or complementary techniques have been developed, including the most promising PCR (Polymerase Chain Reaction), NIR (Near Infrared) microscopy, and immunochemical methods. In this paper a comparative analysis of the results obtained by testing 27 samples of feed for the presence of meat-bone meal derived from cattle, using three different commercial tests is presented. Even though the principle of immunochemical tests is based on detection of thermostable bovine muscle protein, Troponin-I, various characteristics of diagnostic kits used were determined: the limit of detection at the level of 0.5% of bovine protein in animal feed and the accuracy, sensitivity and 100% specificity, up to complete unsensitivity. Objective of the study was to show the possible failures of inadequate test choice for the control of animal feed and the importance of validation and verification of laboratory methods. Also, it was established that an absolute transfer of methods intended for the analysis of food products of animal origin to animal feed, as related matrix, is not always possible.