Mycobiota in poultry feeds and natural occurrence of aflatoxins,fumonisins and zearalenone in the Rio de Janeiro State, Brazil

The intake of mycotoxin-contaminated feeds can lead to nutrient losses and may have adverse effects on animal health and on productivity. The aims of this study were (1) to determine the mycobiota present in poultry feed samples, and (2) to evaluate the natural occurrence of aflatoxin B₁, fumonisin B₁ and zearalenone. Fungal counts were similar between all culture media tested (10³ CFU g⁻¹). The most frequent genus isolated was Penicillium spp. (41.26%) followed by Aspergillus spp. (33.33%) and Fusarium spp. (20.63%). High precision liquid chromatography was applied to quantify aflatoxin B₁ and fumonisin B₁. Thin layer chromatography was used to determine zearalenone levels. Aflatoxin B₁ values ranged between 1.2 and 17.5 μg kg⁻¹. Fumonisin B₁ levels ranged between 1.5 and 5.5 μg g⁻¹. Zearalenone levels ranged between 0.1 and 7 μg g⁻¹. The present study shows the simultaneous occurrence of two carcinogenic mycotoxins, aflatoxin B₁ and fumonisin B₁, together with another Fusarium mycotoxin (zearalenone) in␣feed intended for poultry consumption. Many samples contained AFB₁ levels near the permissible maximum and it could affect young animals. A synergistic toxic response is possible in animals under simultaneous exposure.