Increased concern over mycotoxin contamination of corn and DDGS is reflected in the availability of a wide range of mycotoxin test kits displayed at the 2010 International Poultry Expo/International Feed Expo. Over the past five years, immuno-based rapid mycotoxin detection kits have become easier to use.
Most of the new systems use simple hand-held equipment for manual extraction with test strips providing a qualitative result within minutes. Simple desktop chromatographic readers are also available for qualitative results.
Cost and convenience
Most of the test kit assays cost in the region $5 per sample which is acceptable, given the need to screen ingredients for the presence of mycotoxins which can adversely affect performance, result in claims for damages in addition to complying with statutory upper limits.
Results from test kits are only as reliable as the sample which is collected and processed. Since mycotoxins are unevenly distributed in consignments of grains, standard procedures are required to obtain representative samples. The USDA Grain Inspection Packers and Stockyards Administration provides sampling guidelines on its Web site.
Generally one sample obtained with a 12 foot probe from a hopper car should be adequate. In contrast 5 to 7, 6 foot probes are required from a trailer delivered to an elevator or mill by a farmer. Physical inspection of consignments is essential.
Evidence of mold contamination indicates the need for a screening assay. Many mills rely on ultraviolet (black light) detection for aflatoxin. Florescence indicates the presence of kogic acid a metabolite of aflatoxin. High levels of aflatoxin may however be present without displaying fluorescence.