Introduction 2 Methods 2.1 Materials 2.2 Procedure for production 2.3 Process control 2.4 Organization of the ring trial 2.5 Analysis of results 3 Results 3.1 Application of the method and reporting 3.2 Microscopic procedure 3.3 Microscopic detection 3.4 Detection by PCR 4 Discussion 4.1 Specificity and sensitivity 4.2 Application of the microscopic method 4.3 PCR 5 Conclusions and recommendations 5.1 Conclusions 5.2 Recommendations Introduction to the test Basic instructions for the test procedure Report form for procedure details Report form: results List of participants Details of procedures applied, microscopic method Results: presence of animal proteins, microscopic detection Results: reporting details and evaluation, microscopic detection Results: PCR ruminant PCR Ruminant material was correctly detected in both samples containing 0.1% (w/w) of terrestrial animal material in all 20 cases where PCR was applied. In the two samples without added terrestrial animal material, but still containing the bakery by-products, ruminant DNA was detected as far as analysed, except for one participant who reported negative. The list of recognised sources such as milk and milk products, and ruminant gelatine can be extended with bakery by-products, which is important for the recycling of food by-products.

A.D. Wentzel)• Food and Consumer Product Safety Authority (NVWA; K. Zwaagstra) Cover photo: Bone fragments of cod (left), herring (upper right) and chicken (below).