NOAELs (no observed adverse effect level) were set at 5 mg/kg feed for broiler chickens and laying hens and 7 mg/kg feed for ducks and turkeys; matching the guidance values of 5 mg/kg poultry feed for DON in the EU (2016/1319/EC).

Recent scientific information indicated that these levels should be lower. The EFSA Panel thus assessed studies published between July 31, 2016 and April 19, 2022.

Several studies with broiler chickens showed that DON triggers decreased villus heights and intestinal damage at levels as low as 1.9 mg/kg feed. These intestinal damages being considered as adverse for animal health, a new reference of 0.6 mg/kg feed was retained, based on the 1.9 ppm value and applying an uncertainty factor (UF) of 3.

Similarly with turkeys, adverse effects of DON on zootechnical performance and intestinal morphology were observed at levels of 1.7 mg/kg feed, bringing down the reference value at 0.6 mg/kg feed. Reference values for ducks and laying hens remain unchanged, respectively 7 and 5 mg/kg feed.

The Panel also evaluated the exposure of broilers and turkeys to DON and compared it to the newly established reference values.
Results indicate that mean exposure level to DON and its metabolites is 1.7 times higher than the reference value for broiler chickens, and 2.5 times higher for fattening turkeys (see Image below). Thus, special care must be taken to protect broilers and turkeys from DON and metabolites adverse effects.

Figure: Comparison of estimated DON exposure levels and new reference levels for poultry. Adapted from EFSA Journal 2023;21(2):7806.

Reference: EFSA Panel CONTAM, 2023. Assessment of information as regards the toxicity of deoxynivalenol for horses and poultry. EFSA Journal, 21(2):7806. https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2023.7806