Report on detection and traceability

Report of the desk studies on detection and traceability of GMOs as consumed by animals

Summary of WP2 [+]:

The aim of Work package 2 was to explore which possibilities exist to determine a livestock animal’s previous consumption of animal feed containing GM ingredients, through a desk study compiling and analysing the available and public information on GM feed consumption measurement. Such measurements, if feasible, could help identify animals exposed to specific GM feeds and those that are unexposed, so as to be able to distinguish between exposed groups and non-exposed groups, as well as to link possible health impacts observed in these groups with exposure. Through the desk study, the following topics were reviewed:
• The possibility to detect GM DNA and proteins in samples from animals as measure of its exposure,
• Methods for detecting multiple GMOs in animal feeds (including new generation approaches),
• Suitable sampling points for the analysis of specific GMO along de feed chain, and
• Suitability of the documentary GMO traceability tools to record GMO consumption by animals.

With regard to the possibility to detect transgenic DNA, the review concluded that it was difficult to compare the various studies published on the topic given the divergence in conditions and test methods used. One general conclusion that could be inferred from the research, though, is that a number of studies have shown that plant DNA (not specifically transgenic DNA) is not fully degraded in the gastrointestinal tract. It was recommended to stimulate cooperation and standardization of test protocols for the purpose of testing for transgenic DNA in plants and animals, particularly for the polymerase-chain reaction (PCR) which is commonly used method for this purpose. For transgenic proteins, it was concluded that it was unlikely that immunochemical methods for detection of such proteins could reliably indicate previous exposure of an animal to GM-crop-derived feeds given, among others, the likely absence of antigenic fragments in animal tissues and fluids, as well as the difficulty of measuring protein fragments in complex biological environments. Consideration was also given to the possibility of identifying changes in the metabolome of animals as a possible indirect effect of exposure of livestock animals This Work Package has already been finalized and the results have thus been summarized in its final report