Improving consistency in milk somatic cell counting – Guidance on application of EC JRC Certified Reference Material released

01 March 2021

Joint guidance prepared by IDF and ICAR represents a further step towards better equivalence in  somatic cell counting worldwide.

Milk somatic cell count (SCC) is a widely used indicator for monitoring the udder health of several mammalian species and is relevant in food hygiene regulations, milk payment testing, farm management and breeding programmes.

In February 2020, the European Commission Joint Research Centre (EC JRC) launched a new certified reference material (CRM ERM®-BD001) for somatic cell counting in milk. This reference material is 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.

Release of supporting guidance is an important next step

The additional guidance released today by IDF and ICAR provides further information on the use of this material to establish international metrological traceability for milk analyses.

IDF Director General Caroline Emond:

“The counting of somatic cells relies on the performance of high-capacity routine somatic cell counters. However, prior to the release of reference materials, no robust common reference was available.  The launch of this additional guidance is one of the tangible outcomes of a close cooperation between IDF and ICAR to promote a better global equivalence in somatic cell counting in milk.”

Description of the EC JRC Certified Reference Material

 Sets of CRM ERM®-BD001 are available from EC JRC and its authorised distributors and they are delivered in sachets, see here. Each sachet contains two bottles with 14g spray-dried cow milk in an inert gas atmosphere (argon), one  with a low SCC and one with a high SCC. Following accompanying instruction protocols for reconstitution, the resulting samples will contain about 60 000 and 1 200 000 cells/mL respectively.

For the first batch, a total of thirty-two laboratories around the globe participated in the characterisation exercise. The stated certified reference values are to be considered as robust estimates of the true SCC values of these materials.

The reference materials’ documentation includes instructions on the reconstitution and defines the intended use: quality control material for both reference methods and routine methods and calibration material for routine methods. Moreover, the materials can be used to assign values to in-house materials.

Further information and resources

  • A copy of the IDF/ICAR Guidance is  available here (free download)
  • The reference materials can be acquired directly through EC JRC or its authorized reference material distributors.
  • IDF and ICAR organized a joint webinar on 3 December 2020 to explain the development and the possible applications of the certified reference material and how to cope with transition issues in case of re-anchoring routine somatic cell counting to this now available ‘golden’ standard. The recording and presentations are available : » ICAR / IDF Webinar 3 December 2020 | ICAR