Evaluation of Feeds for Occurrence of Aflatoxin and Safety

Abstract. Aflatoxins produced by Aspergillus flavus and Aspergillus parasiticus are highly carcinogenic. The objective of the study was to investigate the occurrence of aflatoxin B1 (AFB1) in dairy cow feed ingredients and total mix ration (TMR) for low- and high-yielding dairy cows. Subsequently, the level of aflatoxin M1 (AFM1) in raw milk was measured after 12 to 24 h of feeding with the examined feed complexes. All measurements were done using a validated enzyme linked immunosorbent assay (ELISA). AFB1 and AFM1 were detected in 100% of feed and milk samples, respectively. The average concentration of AFB1 in feed ingredients and the concentration of AFB1 in TMRs were in the range of 1.10-104.70 μg/kg and 10.97-56.01 μg/kg, respectively. The average concentration of AFM1 in all milk samples was 77.04 ng/L. It was observed that the average concentration of AFB1 and AFM1 during rainy season was significantly more than during dry season. Corn silage was determined as the most contaminated of all the feed examined for AFB1 content. Furthermore, the AFM1 in 75% of milk samples obtained from high-yielding dairy cows and 25% of milk samples obtained from low-yielding dairy cows were higher than the European maximum limit of 50 ng/L. Based on our findings, the occurrence of aflatoxin in feed and milk samples were related to climatic condition and cows‘ milk yield. It was concluded that good farm management practices are vital to control aflatoxin contamination in feed and milk.