Monitoring of Mycotoxins in Feed for Goats and Their Residues in Milk

Abstract

Aflatoxins are mainly produced by Aspergillus flavus and A. parasiticus, whereas A. flavus, under different conditions, also can produce cyclopiazonic acid (CPA). Several studies on mycotoxins in feed and cow milk have been reported, but the investigation of the co-occurrence of aflatoxins and CPA in feed and goat milk is an unprecedent study in Brazil. This study aimed to evaluate the presence of aflatoxins and cyclopiazonic acid in diets intended for dairy goats and their residues in milk in 10 familiar properties of Southwestern São Paulo region, totalizing 128 samples of feed and 120 samples of milk. Aflatoxins have been extracted and purified in an immunoaffinity column specific for aflatoxins B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) and aflatoxin M1 (AFM1). The analyses for detection and quantification of toxins were performed by high-performance liquid chromatography. From the analyses of the feeds, 2.34% of these were contaminated with aflatoxin at levels ranging from: 3.65 to 36.93 µg/kg for AFB1; 0.35 to 2.46 µg/kg for AFB2; trace to 46.06 µg/ kg for AFG1 and 0.61 to 1.65 µg/ kg for AFG2. One sample showed a concentration of 87.1 µg/kg, above that allowed by Brazilian law. Concerning CPA, 3.12% of the feed samples were positive for it at concentrations ranging from trace to 1.90 µg/kg. AFM1 and CPA were not detected in the milk samples. The results demonstrate that low contamination by mycotoxins in feeds and the absence of AFM1 and CPA in milk indicate best practices in the management and storage of these feeds.