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Improving the diagnosis of deoxynivalenol ingestion in rainbow trout By Rui A. Gonçalves MSc, Scientist - Aquaculture, BIOMIN.

Future growth and sustainability of the aquaculture industry depend on the sector’s ability to identify economically viable and environmentally friendly alternatives to marine-derived ingredients. In recent years, the industry has concentrated efforts on finding alternative sources of protein to substitute fishmeal in aquafeeds. Consequently, many new alternatives are available, e.g. insect meal, macroalgae meal or single-cell protein. However, high costs and limited availability are still challenges that must be overcome for these novel alternative protein sources. Plant-based meals seem to be one of the most promising and viable alternative solutions, but a common problem arising from the use of plant ingredients is the presence of mycotoxins. The trend to replace marine-derived ingredients with plant meals is expected to continue (Figure 1). Mycotoxin management is therefore an important step to avoid performance losses and disease vulnerability.

Fig. 1. Percentage of fishmeal inclusion in aquaculture species. Data obtained from Tacon and Metian, 2008.

What is deoxynivalenol? Mycotoxins are toxic secondary metabolites produced by moulds and fungi, which can be produced on agricultural commodities before and/or after harvest, during transportation or storage. Mycotoxins are a significant problem worldwide, causing adverse health outcomes when consumed by humans and animals, and are responsible for significant global economic losses due to

condemned agricultural products. Deoxynivalenol (DON) is one of more than 400 mycotoxins that have been identified so far. DON is produced by Fusarium fungi, which are generally produced in the field rather than under storage conditions. This means that DON is present on the plant-based raw materials used to produce aquafeeds, as mycotoxins commonly occur in plant materials and are not destroyed during most processing operations.

Hatcheryfeed vol 6 issue 3 2018