M.Sc.(Agric.) Jan Sten Joergensen,
Danish Plant Directorate, DK2800 Lyngby


Constituents of animal origin are in Directive 2003/126/EC defined as “Products from processing bodies and body parts of mammals, poultry and fish”. Meat- and bone meal is defined as a “Product obtained by heating, drying and grinding whole or parts of warm-blooded land animals from which the fat may have been partially extracted or physically removed. The product must be substantially free of hooves, horn, bristle, hair and feathers as well as digestive tract content” (DIR 96/25/EC).

The detection of ingredients of animal origin by microscopy is described in the annex to the DIR 2003/126/EC. From August 27th this directive is replaced by Regulation 152/2009, and the microscopic method is described in the Annex VI, which is identical to the former annex. The present method is basically established by improving a former method developed by the organization IAG (International Association of Feedstuff Analysis – Section Feedstuff Microscopy) http://www.iag-micro.org/ , and the improvement obtained from the European Project, STRATFEED (G6RD-2000-CT-00414) http://stratfeed.cra.wallonie.be/ .

The microscopic method is for the moment the only approved method for detection of ingredients from animal protein in feed. Other methods may be used in order to improve the detection by microscopy, and to specify further the origin of animal constituents detected.

The detection is made in both sieve fractions from a representative sample which has undergone a suitable sample preparation, as well as in a concentrated sediment of the sample, produced by the principle of differences in specific gravity of particles.

In sieve fractions vegetable ingredients, muscle fibers, animal hairs, blood, feathers and the same animal ingredients (e.g. bone fragments) as found in the sediment can be identified. In concentrated sediment beside minerals, also bone fragments form terrestrial animals and fish, cartilages, fish scales and egg scales can be found. If present these ingredients will be much more concentrated as in the sieve fractions. Identification of different ingredients is made on microscopically identifiable characteristics.

The microscopic method for detection of MBM cannot distinguish between muscle fibers from terrestrial animals and fish. Based on a combination of bone shape, lacunae shape and density, present or absent of canaliculae and bone colour it is possible to differentiate between bones from terrestrial animals and fish. To a certain degree it is possible to differentiate bones from mammals and poultry.

Validation and several ringtest from the IAG organization and the Community Reference Laboratory for Animal Protein in Gembloux, Belgium (CRL-AP) have shown that in animal feedstuffs, MBM in concentrations much below 0,1 percent can be identified.