Jul 10, 2021 · Occurrence of AFB 1 in feeds. A total of 3,500 feed samples, including 2,083 feedstuff and 1,417 complete feeds, were collected between 2018 and 2020 for analysis of AFB 1 (Table 2).AFB 1 was detected in 81.9–100% of feedstuff and complete feeds, with the average levels ranging from 1.2–27.4 μg/kg. The highest median concentration of AFB 1 was 32.0 μg/kg