Compliance between Food and Feed Safety: Eight-Year Survey (2013-2021) of Aflatoxin M1 in Raw Milk and Aflatoxin B1 in Feed in Northern Italy

Aflatoxins (AFs) are fungal metabolites that are found in feed and food. When ruminants eat feed contaminated with aflatoxin B1 (AFB1), it is metabolised and aflatoxin M1 (AFM1) is excreted in the milk. Aflatoxins can result in hepatotoxic, carcinogenic, and immunosuppressive effects. The European Union thus set a low threshold limit (50 ng/L) for presence of AFM1 in milk. This was in view of its possible presence also in dairy products and that quantification of these toxins is mandatory for milk suppliers. In the present study, a total of 95,882 samples of whole raw milk, collected in northern Italy between 2013 and 2021, were evaluated for presence of AFM1 using an ELISA (enzyme-linked immunosorbent assay) method. The study also evaluated the relationship between feed materials collected from the same farms in the same area during the same period (2013-2021) and milk contamination. Only 667 milk samples out of 95,882 samples analysed (0.7%) showed AFM1 values higher than the EU threshold limit of 50 ng/L. A total of 390 samples (0.4%) showed values between 40 and 50 ng/L, thus requiring corrective action despite not surpassing the regulatory threshold. Combining feed contamination and milk contamination data, some feedingstuffs seem to be more effective in defying potential carryover of AFs from feed to milk. Combining the results, it can be concluded that a robust monitoring system that covers both feed, with a special focus on high risk/sentinel matrices, and milk is essential to guarantee high quality and safety standards of dairy products.

Automated summary

This study analyzed 95,882 samples of raw milk collected in northern Italy between 2013 and 2021 for the presence of aflatoxin M1 (AFM1) using an enzyme-linked immunosorbent assay method. Only 0.7% of the samples exceeded the European Union threshold limit of 50 ng/L for AFM1. The study also identified certain feed materials that were more likely to result in AFs transferring from feed to milk. The findings highlight the importance of a robust monitoring system covering both feed and milk to ensure the quality and safety of dairy products.