The occurrence and seasonal variation of aflatoxin B1 and zearalenone concentrations in poultry feeds.

The present study aimed to investigate the contamination of poultry feed with aflatoxin B1 and zearalenone at laying hen farms in Tehran suburbs. The poultry feed was selected from five laying hen farms. A total of 60 poultry feed samples were collected from each farm during four consecutive seasons, from spring to winter of 2021. High-performance liquid chromatography was used to determine the amount of aflatoxin B1 and zearalenone. The mean aflatoxin B1 and zearalenone concentrations in various seasons showed significant differences (p<0.01). The highest reported aflatoxin concentration was in winter, with a mean concentration of 1366.53±77.85 ng/kg. The lowest concentrations were reported in autumn and summer, indicating a significant difference (p<0.01). The highest concentration of zearalenone was reported in summer, with a mean concentration of 150.72±10.35 μg/kg. The lowest concentration was reported in winter, with a mean concentration of 22.87±10.35 μg/kg, indicating a statistically significant difference (p<0.01). Overall, the concentrations of aflatoxin B1 and zearalenone toxins significantly differed in various poultry farms. The poultry farm D had the highest aflatoxin contamination with a mean concentration of 648.08±59.89 ng/kg. Poultry farms A, B, and C had the highest zearalenone concentrations with mean concentrations of 125.17±20.61, 96.04±20.61, and 99.49±20.61 μg/kg, respectively. Autumn was the only season showing significant differences regarding zearalenone toxin concentration in poultry farms.