EFFECT OF SORBENTIA ON CARRY-OVER OF AFLATOXIN FROM COW FEED TO MILK

In a Latin square experiment with 24 cows in mid lactation the effect of 1 % bentonite on the carry-over of aflatoxin B1 (AFB1) from feed to aflatoxin M1 (AFM1) in milk was determined. The compound feed was naturally contaminated with AFB1 at a level of 10 mug/kg. The carry-over of AFB1 and the AFM1 content of milk were significantly reduced one third by absorption of aflatoxin onto bentonite. The presence of 1 % bentonite in feed reduced the analytical recovery of AFB1 from feed by about 20 %. The usefulness of bentonite and aluminosilicate in a practical relevant situation, i.e. at AFB1 levels at approx. the EC tolerance limit of 5 mug/kg, was determined in the same experimental design with 9 cows. In this second experiment with an AFB1 contamination level of 2.8 mug/kg feed, bentonite reduced also the aflatoxin carry-over and thus the AFM1 content of milk with one third. In contrast to that the use of 1 % aluminosilicate had no effect. In compound feed that meets the EC tolerance limit with respect to the AFB1-contamination, bentonite is an effective agent to reduce the existing risk of producing milk with an intolerable AFM1 level, especially when this feed is used for cows with high milk yield.