Contamination levels of aflatoxin M1 in bulk raw milk of Chaloos and Ramsar

Aflatoxin M1 (AFM1) appears in milk as a direct result of the ingestion of feed contaminated with aflatoxin B1 by cattle. This study was conducted to investigate the contamination rate of raw milk whit aflatoxin M1 in Chaloos and Ramsar raw milk collection centers. Two hundred bulk raw milk samples were collected during winter (January and February) and summer (June and July) seasons. The milk samples were analyzed by ELISA method for the presence of AFM1. During the winter, AFM1 was detected in 100% and 59/79% of the bulk raw milk samples in Ramsar and Chaloos, respectively; however, during summer 83/52% and 50/1 of the samples was found as positive in Ramsar and Chaloos, respectively. Furthermore, 45% of Ramsar and 30% of Chaloos bulk milk samples showed higher contamination level of AFM1 than maximum tolerance limit (50 ng/l) accepted by National Standard as well as European Union. Although, the difference between the contamination rate in samples obtained during summer and winter seasons was not statistically significantly, (p<0/05) significant difference (p<0/05) was observed between Chaloos and Ramsar samples in each season. Moreover, highest contamination rate was found in February.