Miller Magazine Issue: 150 June 2022

78 COVER STORY MILLER / JUNE 2022 What are some interesting approaches to mitigate mycotoxins? Managing water activity is an area of increasing focus for defending against moulds in grains. For several years, the pet food industry has evaluated how even low water activity levels can affect mould growth. From a nutritional perspective, managing moulds is critical to protecting the integrity of the animal’s diet. Mould growth results in a noticeable difference in the nutritional quality of corn including a drop in metabolic energy, crude pro- tein and fat content. (Figure 1) Where should mould prevention areas focus? Mould preven- tion efforts should start in the field and continue through transport, storage and production. In the field, weather, drought, harvest rains, pests and mould growth can harm quality. Scoring systems created by the USDA are a helpful tool for evaluating quality fac- tors including grade, moisture, nutritional profile, physical quality and mycotoxin presence. Scoring systems are available for corn and other grains and oilseeds. In storage, temperature shifts can allow condensation build-up and conditions for moisture to pool on stored grain. Grains and oilseeds can be contaminated with mycotoxins during transport or at the feed mill where moulds are typically present in screw conveyors, ingredient bins, elevator legs, pellet mill coolers, feed bins and trucks. What economic consequences do mould pose? The average nutritional value of different grains lost to mould has been estimated to be up to 7% for wheat and barley and 6% for corn. Given cur- rent grain pric- ing, this decline equates to more than $200,000 in damage for ev- ery 10,000 tons. (Figure 2) How can the p r o d u c t i o n chain manage this risk? A third-party critical control point assess- ment can identify possible risks and suggest practices to help mitigate threats. Practices can include using natural or artificial drying, monitor- ing stored grain and installing aeration and scoring systems, using portable moisture analysis to run spot checks, having a conveyer system that mini- mizes grain damage and cleaning conveyor belts to remove broken kernels/debris. Figure 1 – Mould growth robs stored grains of nutritional quality, reducing nutrition available to livestock. Figure 2 – Mould-based damage to grain quality can quickly become an economic challenge for producers.