Detection of Aflatoxin Contamination of Dairy Production Chain in the Northwest Region of Rio Grande do Sul, Brazil

Abstract

The present study evaluates levels of aflatoxin contamination involving small dairy farms from the in the Northwest region of Rio Grande do Sul, Brazil. The objectives of this trial is: quantify lactating cow diet and raw for bulk milk Aflatoxin B1 (AFB1) contamination; evaluate the use of a mycotoxin adsorbent on cows submitted to semi-confinement raising; and verify the presence of AFM1 contamination on UHT and powdered milk commercialized locally. For this, 17 farms were selected. During the experimental period, every lactating cow on each herd received 50 g/day of a commercial mycotoxin adsorbent for dairy cows (100% bentonite). From each farm, bulk milk, corn silage and concentrate samples were collected for aflatoxin quantification. Aflatoxin M1 was detected in all milk samples examined from each farm, but the levels were within the allowed by the legislation. Aflatoxin B1 was also detected in all samples of corn silage and concentrate. The mycotoxin adsorbent used reduced (p < 0.05) AFM1 contamination in milk. AFM1 milk contamination levels observed on commercialized milk also respected Brazilian requirements. It is possible to conclude that there is a high incidence of Aflatoxin B1 contamination on corn silage and dairy cows concentrates in family farms from South Brazil region. Based on the condition in which the present study was conducted, the use of a mycotoxin adsorbent reduced the levels of AFM in milk in production system. However, the locally produced milk and commercial milk were below the AFM levels accepted by the National Requirements for AFM1 contamination.