VDLUFA section VI Feedstuff Analysis regularly conducts two proficiency tests for quality assurance. These tests are the “VDLUFA Feedstuff Proficiency Test” which includes 3 samples and is organized every year and the ring test “Mycotoxins”, where the number of samples and the timeframe vary. The Working Group Microscopy annually executes multiple ring tests in collaboration with the IAG (International Association for Feedingstuff Analysis). Collaborative trials for method development are an additional focus of the work conducted by the section. Some examples include the test from 2005/2006 for the qualitative and quantitative detection of genetically modified feed (331M) along with 5 further tests for probiotic cultures as feed additives.