SPECIAL STORY FEED & ADDITIVE MAGAZINE August 2023 49 Next to the emerging mycotoxins, fusaric acid, fumonisins (mainly represented by fumonisin B1), type B trichothecenes (mainly represented by deoxynivalenol), type A trichothecenes (mainly represented by T-2 toxin), and zearalenone were other highly present mycotoxin groups in the tested feed ingredient samples. For example, in corn, the maximum concentrations of type A (713 ppb) and type B (8,049 ppb) trichothecenes exceeded the current recommended limit in cereals intended for animal feeds: T-2 toxin at 500 and deoxynivalenol at 8,000 ppb (EC, 2006). Similar to emerging mycotoxins, there is no guidance level for fusaric acid, which had a high average (616.2 ppb) and maximum (3,221 ppb) concentration in DDGS samples. RISK QUANTIFICATION IN THE SHRIMP FEEDS The total risk of mycotoxin contamination in the shrimp feeds was estimated by using the Alltech® DIET™ Estimator tool. It combines the inclusion rates of individual plant-based ingredients in the diet with their mycotoxin contamination data. For the current risk estimation, a shrimp feed recipe from the Practical Aquaculture Feed Formulation Database (PAFF) was used as an example (soybean meal inclusion at 35% and wheat at 28%), and mycotoxin results derived from Alltech 37+ analyzed samples in the first half of 2023. In this case, the final Alltech risk equivalent quantity (REQ), was estimated at 10.4 ppb, which is considered moderate for shrimp (Figure 1, PAFF). Unique to Alltech, REQ is the measure of the cumulative presence of mycotoxins in ingredients or feeds. When shrimp formulations from Southeast Asia (Figure 1, Southeast Asia) and Latin America (Figure 1, Latin America) were analyzed with this tool, the REQs were estimated as moderate and high, respectively. Thus, in addition to the mycotoxin data in feed ingredients, the inclusion rates also matter for calculating the overall risk of contamination in shrimp feeds. The increased mycotoxin risk in the Latin American diet can be attributed to the inclusion of ground corn. MYCOTOXINS’ EFFECTS ON SHRIMP PRODUCTIVITY AND HEALTH Shrimp farming operations are located in tropical and subtropical regions, where climatic conditions for Aspergillus fungi are traditionally favorable, and thus aflatoxin B1 is likely present. Research has shown that aflatoxin B1 above 1 mg/kg reduces survival rate and growth, is bioaccumulated in tissues, Figure 1. Estimation of REQ based on the inclusion level of plant-based ingredients used in a shrimp feed
RkJQdWJsaXNoZXIy MTUxNjkxNQ==