Seasonal variation of aflatoxin B1 content in dairy feed

Abstract

Afatoxin B1 (AFB1) is a fungal metabolite and highly carcinogenic compound of category 1 according to the International Agency for Research on Cancer. In the liver AFB1 from contaminated feed is bioconverted into afatoxin M1 and can be easily diffused to the animal milk. Provision of healthy milk for humans, particularly infants and adults, therefore, entails monitoring of AFB1 level in the feed for dairy animals. In the present study, AFB1 level was monitored in three different types of animal feed comprising commercially available animal feed, fresh fodder and leftover bread fed to dairy animals between October 2014 and September 2015. AFB1 was found in all collected feed samples at the amounts: 30.5%, 2.8% and 88.9% in commercial feed, fresh fodder and leftover bread samples, respectively. All these levels were over the EU permissible limits (5 μg · kg-1). Mean maximum levels of AFB1 were observed in all samples collected in the winter season, whereas the mean minimum levels - in the summer months. The results of the present study indicated that the leftover bread samples and commercial feed contain high levels of AFB1, and so strict measures should be adopted to prevent dairy animal feed and at the same time the animal milk from afatoxin contamination.