Mycotoxins are toxic secondary metabolites produced by fungi that contaminate a wide variety of grains and finished feed . The prevalence of m ycotoxins is different between regions, although global trade and climate change play a role in homogenizing the contamination profile worldwide. S ome studies have shown that mycotoxins cost the livestock and aquaculture industry billions in economic losses each year.
Aquatic species can be quite sensitive to mycotoxins and the risk increases with the growing tendency to include plant-derived protein sources which are more economic than fish meal or fish oil in aquatic diets.
Since 2004, Biomin has conducted a survey for the best studied mycotoxins, namely aflatoxins (Afla ), zearalenone (ZEN), deoxynivalenol (DON), T-2 toxin (T-2), fumonisins (FUM) and ochratoxin A (OTA). In a survey that encompasses 230 aqua feed samples DON , ZEN and FUM were present in more than half of all of these samples (70%, 62% and 58%, respectively). The incidence of AFLA and OTA in these samples (29%) was also considerably high . The main plant-based ingredients included in aqua feed such as corn & corn by-products, wheat, wheat bran, soybean and soybean meal also showed the presence of mycotoxins but more importantly confirmed that co-contamination is very common.
Mycotoxins can cause different effects in aquatic species including reduced growth and increased susceptibility to diseases due to their immunosuppressive effects. In this study, it could be shown that Mycofix ® had a positive effect on growth performance, immune parameters and disease resistance in tilapia that were exposed to a diet containing OTA at levels below the European legislative limits. The results also underline that Mycofix® contributed to improved production and economic potential of the animals.