Mycotoxins are secondary metabolites of filamentous fungi that are produced in various stages of cultivation, harvesting and storage on various agricultural products. The most important species of fungi that produce mycotoxins in animal feed include Fusarium, Aspergillus, Penicillium, Alternaria and Clavicps. These species can produce mycotoxins under suitable conditions of temperature, humidity and pH.
So far, more than 400 types of mycotoxins have been identified, the most important of which in the animal husbandry industry are six groups of aflatoxins (including aflatoxin B1, B2, G1 and G2), trichocenes including trichocenes A (such as T-2, HT-2 and disethoxyscripnol ) and trichothecenes B (such as doxynivalenol or DON, nivalenol and acetyldoxynivalenol), zearalenone, ochratoxins, ergot alkaloids (including ergometrine, ergosine, ergotamine and clavines) and fiumensins (including fiumensin B1, B2 and B3) are classified. Meanwhile, trichocenes with 170 types have the largest variety among known mycotoxins.
The global distribution and extent of contamination around the world have caused many concerns about these toxins, so that according to the report of the World Food Organization (FAO), more than 25% of the food in the world is contaminated with these types of toxins. Based on the results of the research conducted (Babaei et al., 2009; Borji et al., 2016; Jamali and Moeini, 2017; Sattari et al., 2018; Hashemi et al., 2019; Yeganehparast et al., 2016) contamination with these toxins in Iran is more than the global average.
The limit defined for mycotoxins in many countries is based on the 1995 World Food Organization. There are differences in the amount of dietary allowance in the European Union, the United States and some European countries.
The maximum permissible level for mycotoxins based on the proposal of the World Food Organization (FAO)
The point that should be noted is that these limits are defined mostly to reduce the risk of mycotoxins in human health and less for animal health, and this is despite the presence of toxins in amounts lower than these standards, the liver is not able to detoxify these toxins. He comes into action and does a lot of activities. In fact, the liver, as a filter, detects very small amounts of toxins and detoxifies them. Considering that the liver spends a lot of energy to detoxify these toxins and also dedicates a percentage of its activities to this, the efficiency of the animal's energy intake decreases. In addition, poisons in very small amounts maintain their activity on a wide level and exert their destructive effects on all organs and tissues of the body. Therefore, in practice, we should not be satisfied with these standards and management programs should be adjusted based on reducing the availability of these poisons to values much lower than these standards.
The most common effect of mycotoxins on animal performance is the reduction of production efficiency and the performance of their immune system. Some poisons also have special physiological effects on the performance of animals.
The effect of different mycotoxins in ruminants
Effect of different mycotoxins in poultry
The effect of different mycotoxins in aquatic animals
The sensitivity of different species of animals to mycotoxins is different. For example, ruminants are more sensitive to T-2 poison than other poisons, while aquatic animals are more sensitive to aflatoxins.
Sensitivity of different species to mycotoxins