The European Commission’s Joint Research Centre (JRC) has announced the launch of the first certified reference materials for somatic cell counting in milk, an integral part in a joint project of the International Dairy Federation (IDF) and the International Committee for Animal Recording (ICAR) to establish an international reference system for somatic cell counting in raw milk.

The reference materials are the result of several years of cooperation between IDF, ICAR and EC JRC, the European Commission’s science and knowledge service. The materials were developed in response to an identified need to have available a common, robust, and internationally accepted anchor point to implement and safeguard equivalent somatic cell counting worldwide.

Significant importance for the sector

Somatic cell counting is a key indicator for udder health in several lactating animals, including dairy cows. Accurate counting therefore has relevance in food quality regulations, milk payment testing, farm management and breeding programmes. The counting of somatic cells relies on the performance of high capacity routine somatic cell counters. However, prior to the release of the new reference materials, no robust common reference was available.

Caroline Emond, Director General of IDF said: “Current practice requires milk laboratories in different geographies to link to their own individual reference materials, creating potential issues with comparability and thus equivalence. Thanks to the combined expertise of IDF, ICAR and the JRC, we are a step closer to overcoming these issues. This work could not have been achieved without the significant expertise and tireless efforts of the IDF/ICAR network and the Reference Materials Unit within JRC’s Directorate F (Health, Consumers and Reference Materials), located in Geel, Belgium”.

The reference materials (ERM-BD001) are arranged as sets. Each set consists of two bottles with spray-dried cow milk, one with low and one with high somatic cell count, characterized by means of an interlaboratory comparison with 32 laboratories worldwide. The reference materials’ documentation includes instructions on the reconstitution, and defines the intended use: calibration material for routine methods, and quality control material for both reference methods and routine methods. Moreover, the materials can be used to assign values to in-house materials.

Dr Silvia Orlandini, Milk Analysis Certification Executive for ICAR said: “These reference materials will be of great practical importance to many within the livestock sector, including raw milk testing laboratories, national and international bodies responsible for regulations on measuring somatic cell count, supervising bodies in milk payment testing and many others. Looking ahead, IDF and ICAR are working on additional guidance to provide further information on the use of this material to establish international metrological traceability for milk analyses”.

In addition to the applications already mentioned, the material will be of specific interest to dairy herd improvement organisations, QA services, manufacturers and distributors of routine equipment for somatic cell counting, providers of secondary reference materials for somatic cell counting, organizers of proficiency testing, animal health organizations, universities and research institutes and accreditation bodies.

The reference materials can be acquired directly through EC JRC or its authorized reference material distributors [https://ec.europa.eu/jrc/en/reference-materials/catalogue]. It should be noted that delivery may be delayed till the course of May due to the COVID-19 outbreak. For more information about the reference materials, please contact Reinhard Zeleny.