Occurrence of multiple mycotoxins in European feedingstuffs, assessment of dietary intake by farm animals

Mycotoxins, toxic secondary metabolites produced by microscopic filamentous fungi, are ubiquitous contaminants of crop plants and forage representing the main components of compound feeds. More than 300 mycotoxins are known today, but only five of them (aflatoxin B1, deoxynivalenol, zearalenone, fumonisins and ochratoxin A) are regulated by EU legislation for animal feed. The current study reflects the requirements of the European Food Safety Authority for gathering the data allowing reliable quantitative exposure assessments. This is the first report combining the data for the occurrence of 56 mycotoxins produced by Fusarium, Alternaria, Penicillium, Aspergillus, and Claviceps fungi species in 18 classes of non-fermented or fermented feedingstuffs, feedingstuff supplements, and complex compound feeds (altogether 343 samples collected between 2008 and 2012). Samples were extracted by the QuEChERS (Quick Easy Cheap Rugged and Safe) procedure. For separation and target mycotoxins detection, ultra-performance liquid chromatography coupled to tandem mass spectrometry was employed. In most of the investigated feedingstuff commodities, deoxynivalenol, zearalenone, fumonisins, ochratoxin A, enniatins, beauvericin, Alternaria toxins, ergot alkaloids, roquefortine C and mycophenolic acid were quantified, in some cases at concentrations up to thousands of μg/kg, depending on the composition of the particular sample. The broadest spectrum of detected mycotoxins, as well as the highest concentrations, was quantified in dried distillers’ grains with solubles (DDGS). Based on the performed analyses, the dietary intake of particular mycotoxins was estimated considering the feedingstuffs consumption by the respective farm animal. It was found that the most significant exposure of animals occurred after the consumption of ‘basic’ feedings, i.e. maize silage and complex compound feeds for dairy cattle (average dietary intake for the most important mycotoxins were 2.3–5.4 μg/kg of BW for nivalenol, 9.2–10.8 μg/kg of BW for deoxynivalenol, 1–1.4 μg/kg of BW for FUS-X, 0.2–0.4 μg/kg of BW for zearalenone, 0.03–1.8 for enniatins, and 0.5–5.4 μg/kg of BW for mycophenolic acid), complex compound feeds for pigs (in average 12 μg/kg of BW for deoxynivalenol, 0.8 μg/kg of BW for zearalenone, 0.3 μg/kg of BW for fumonisin B1, and 1.8–9.2 μg/kg of BW for enniatins), and complex compound feeds for chickens and laying hens (18.2 μg/kg of BW for deoxynivalenol, 1.1 μg/kg of BW for HT-2 toxin, 0.1 μg/kg of BW for zearalenone, and 0.4–3.9 μg/kg of BW for enniatins). Nevertheless, quite high animal exposure to mycotoxins was calculated also for maize-based DDGS usually used as a supplementary feed. In spite of a lower dosage of these feedingstuff supplements, relatively high mycotoxins concentrations determined here caused the increased dietary intake.