Accueil › ID’info › Mycotoxines, un danger visible comme invisible
Mycotoxins affect all types of plant production: cereals, grass, lucerne, hops, peanuts, etc.
A mycotoxin is a toxic metabolite that may be produced by certain strains of mould, which can have an impact on health and zootechnical performance, depending on the dose and the animal species. Climatic conditions are a determining factor in the production of mycotoxins. Discover the toxicological properties of mycotoxins and how to reduce their presence in raw materials.
The FAO (Food and Agriculture Organization) estimates that over 75% of cereal crops worldwide are affected by mycotoxins at significant levels. More than 300 secondary metabolites have been identified, but only around thirty have real toxic properties that give cause for concern (AFSSA, 2009).
Figure 1 : The main mycotoxins found in raw materials.
There is a potentiation of toxicities and undoubtedly synergistic associations of toxicity. Climatic conditions, influenced by climate change, play an important role in the proliferation of mycotoxin-producing fungi. Climate is the agro-ecosystem factor with the greatest influence on the life cycle of fungi.
Figure 2 : Parameters influencing the development of mycotoxins.
Higher temperatures and prolonged periods of rain create favourable environments for these fungi, increasing the risk of crop contamination.
In Southern and Eastern Europe, warmer and drier than normal years have had an impact on the development of moulds in the field, with a higher incidence of Aspergillus flavus. As for the Fusarium genus, it develops more when water activity (= free water, aw) is high. Northern and Central Europe will be more affected by this type of mycotoxin due to the increase in humidity between now and 2050 (ZINGALES et al., 2022).
In Europe, the 2023-2024 season was marked by a persistent rainfall deficit in the western Mediterranean regions, which hampered sowing and the initial development of winter cereals. Conversely, heavy rainfall and a generally mild winter throughout Europe caused major disruption to the sowing and development of winter crops. These particular weather conditions could favour the development of mycotoxins in cereals. Below is the rainfall for various months in the 2023-2024 season compared with the averages for various months in the 1991-2020 period.
Waht do European regulations say?
The European Union imposes stricts standards for maximum levels of mycotoxins in foodstuffs. In 2024, stricter maximum limits have just been introduced for certain mycotoxins, in response to new data on their long-term effects on human health. The European Commission has been tightening its regulations since 2016. The new regulation lowers the DON mycotoxin threshold for common wheat and barley from 1250 to 1000 µg/kg (Regulation (EU) 2024/1038 of 9 April 2024).
Figure 3 : Maximum authorised content in unprocessed seeds (EU regulation, 2024).
Mycotoxins exert their toxic effects through various mechanisms:
Certain mycotoxins, such as DON, disrupt protein synthesis by binding to ribosomes, leading to cell death.
Mycotoxins can generate reactive oxygen species (ROS), causing oxidative damage to nutrients (lipids, proteins) and DNA. AFB1 is hepatotoxic and can cause acute and chronic liver damage. AFB1 reaches the liver via the portal system and is metabolised by cytochromes to AFB1 8,9-epoxide (AFBO). AFB1 is then capable of inducing the production of ROS such as hydrogen peroxide (H2O2), leading to oxidative stress (D. PAYROS et al. 2021).
In addition, in dairy cows, it can be transformed into AFM1 in the milk, representing a direct risk to human health.
Mycotoxins such as aflatoxins can interact with DNA, causing mutations.
Some mycotoxins, such as zearalenone, mimic or block natural hormones, disrupting normal endocrine function. Bioconversion of zearalenol by animals results in the creation of two metabolites, called α and β zearalenol.
The α -zearalenol form is the more oestrogenic and can have a negative effect on reproduction (C. GURIKAR et al. 2023). In fact, zearalenone acts as an oestrogen receptor agonist, causing hormonal disturbances. In sows, it causes reproductive disorders, abortions and reduced fertility.
Aflatoxins also affect the inflammatory response. They weaken the immune system by inhibiting several macrophage functions such as phagocytosis (MEISSONNIER et al., 2006; OTTINGER and KAATARI, 2000). Animals fed a continuous diet contaminated with mycotoxins may be more susceptible to microbial infections (bacterial, parasitic and viral) and to a reduction in vaccine effectiveness (OSWALD et al., 2005).
Other mycotoxins, such as deoxynivalenol DON, exert their harmful effects in the gastrointestinal tract. Similarly, in the rumen, while some mycotoxins such as DON can be degraded, others such as zearalenone can be activated and thus become more toxic after transformation.
The effects of masked mycotoxins, also known as ‘modified mycotoxins’, can be particularly harmful because they are difficult to detect using standard mycotoxin testing methods. Masked mycotoxins are formed when plants or fungi alter the chemical structure of mycotoxins, making them ‘invisible’ to routine feed analysis.
However, once ingested by animals, these modified toxins can be converted back into their toxic forms during digestion, resulting in a range of adverse effects.
Given their hidden nature, masked mycotoxins pose a silent threat to animal health and production, making regular testing and advanced detection methods essential for effective management.
Figure 4 : Summary diagram of the negative effects of mycotoxins in all species.
The fight against the appearance of mycotoxins begins with the choice of varieties that are more resistant to fusariosis. The sowing period is also an important parameter to take into account.
Before sowing, it is advisable to shred or plough if there are residues of straw or maize stalks. Fungal protection will be necessary to limit the risk of mycotoxins appearing in the grain.
Next, when storing cereals, the grain should be kept in a clean, dry, well-ventilated place to avoid condensation and possible mould.
Figure 5 : Cereal preservation diagram (ARVALIS).
IDAFIX PLUS is a specific blend of organic and inorganic adsorbents combined with essential oil-based fungus and toxin neutralisers. Their physical structures and varied particle sizes are capable of irreversibly associating with several mycotoxins.
IDAFIX PLUS has the ability to interact with polar and apolar mycotoxins as well as bacterial toxins in the digestive tract.
– Broad spectrum of mycotoxins,
-Permanent control of hydrophobicity and CEC.
IDAFIX PLUS can be used on all animal species, with low-dose efficacy and a cost that gives a good return on investment:
– Poultry / pigs: 1 to 2 kg / tonne of feed.
– Large ruminants: 20 to 40 g / day.
– Young animals: 2 kg / tonne of feed.
To find out more about IDAFIX, read our article “How to reduce mycotoxin risks with the IDAFIX range” here.