The current research was conducted to determine the aflatoxigenic and non-aflatoxigenic Aspergillus flavus isolates and the frequency of aflatoxin levels (B, B, G, G), in main feed ingredients (corn and soybean meal) and poultry finished feed (in mash and pellet forms). Eighty-five samples of corn, soybean meal, and poultry finished feed was randomly collected from feed mills in Iran. Regarding macro and microscopic morphological criteria, Aspergillus isolates were identified, and aflatoxins were determined by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). All of poultry feed samples were contaminated with different levels of aflatoxins, ranging from ND (they were not detected in those samples) to 5.58 µg/kg. At all stages of processing, the poultry feed had lower levels of aflatoxins in comparison with the accepted/residue levels of poultry feed mills. Higher amounts of aflatoxins (B, B, G, G, and total) were detected in pelleted feed, compared to other poultry samples (P < 0.05). The total toxin level in mash feed samples reached a maximum of 3.31 ppb. The results indicate that finished feed samples in pellet form may pose a greater risk than their individual ingredients in poultry feed, particularly when suboptimal conditions exist for eliminating fungal populations. So, the prevention and reduction of (Aspergillus section Flavi) are highly important in maintaining quality control of poultry feed, as the production of aflatoxins can occur during the process of converting raw ingredients into finished feed.
