Aflatoxin B1 contamination of feedstuff on a dairy farm in Northern Peru and aflatoxin M1 concentrations in raw milk

Research regarding aflatoxin contamination levels in Peru is limited, although aflatoxin M-1 (AFM(1)) and aflatoxin B-1 (AFB(1)) require surveillance because of their toxicity. European regulations state that the harmonised maximum level (ML) is 5 mu g/kg for AFB(1) in feedstuffs and 0.05 mu g/kg for AFM(1) in milk. Our study aimed to determine the annual variation levels of AFB(1) in ingredients used in feedstuffs for dairy cows and those of AFM(1) in milk at a typical intensive dairy farm in Northern Peru. For 1 year, milk (n=529) and feedstuff samples (n=235) were collected and aflatoxin levels were determined using a lateral flow immunoassay. We found that 16% of milk samples had AFM(1) contamination above the ML. AFM(1) level was significantly higher (P<0.05) in December (end of spring) than that in all other months. Throughout the year, the most used feedstuffs were maize, soybean meal and whole soybean. Among the maize samples (n=77), 2.59% had an AFB(1) level above the ML, whereas 45% had an AFB(1) level below the ML. On the other hand, neither the soybean meal (n=69) nor whole soybean samples (n=64) had an AFB(1) level above the ML, 46.4 and 20%, respectively. In 50% (n=10) of cottonseed meal samples, AFB(1) level was above the ML; in 20% of wheat middling samples, it was above the ML. Cottonseed and wheat middling samples were used for 2 and 5 months, respectively. AFB(1) level in feedstuff showed a significant difference in December (P<0.05) compared with other months, specifically for maize and soybean meal. As the AFM(1) level in milk results from AFB(1) contaminated feedstuff, our results emphasise the need to implement specific quality measures to reduce contamination.