Though aflatoxins are often associated with tropical and subtropical climates, such as those in Rwanda, India, Tunisia, and Ethiopia, climate change may increase their occurrence in crops in countries with traditionally moderate climates, including Greece, Lithuania, Croatia, and France, due to more extreme weather conditions.
That was one of the findings of a new meta-analysis; the researchers compiled data from 100 research papers, analyzing the key mycotoxins.
Global snapshot
The study confirmed that warmer, drier regions have higher levels of aflatoxins, while cooler, wetter areas show more significant contamination from deoxynivalenol.
The authors reported high prevalence and concentrations of fumonisins in South Europe, Africa, and South America, indicating that feed in these regions is impacted by fumonisin contamination.
In addition, the authors found high concentrations of T-2/HT-2 toxins in Central Europe, North America, and North Europe, where cooler and moderate temperatures are more prevalent.
The results also suggested that deoxynivalenol has the highest prevalence in feed components compared to other mycotoxins.
The prevalence and concentration of mycotoxins in feed components depend on the crop type, crop resistance to fungal attacks, weather conditions during the growing seasons, incidence of damage, fungi presence, as well as agriculture practices and management.
“Rwanda and Nigeria had the highest concentrations of aflatoxins and ochratoxin, respectively; France had the highest concentration of T-2 & HT-2 toxin and zearalenone; and Costa Rica had the highest concentration of fumonisin, while Denmark had the highest concentration of deoxynivalenol.”
Red flags
While most contamination levels were below regulatory thresholds, the authors noted that certain hotspots exceeded safe limits, raising red flags for feed safety.
“The synthesized concentration of the mycotoxins in the overall feed components was lower than the regulated and guidance values set by the EU.
“However, in a few cases, the 95th percentile exceeded these concentration values due to high levels of uncertainty attributed to lower sample size, and thus, need to be considered while conducting risk assessments.”
Feed ingredients
The study also aimed to determine the extent of mycotoxin contamination of dairy cow feed components in different countries. The researchers saw that:
- Mixed feed had the highest aflatoxin concentration
- Sunflower had the highest ochratoxin concentration
- DDGS had the highest deoxynivalenol concentration
- Sugar beet had the highest zearalenone concentration, and
- Alfalfa had the highest T-2/HT-2 concentrations.
This variation, they said, highlights the importance of assessing specific ingredients for contamination risks.
The authors believe their analysis can help identify feed and feed components at the highest risk of mycotoxin contamination, particularly in the context of changing climatic conditions.
Companies and regulatory agencies can use the findings of this study to conduct comprehensive risk assessments for human and animal health, they said.
Future research could focus on specific geographical regions, considering factors such as farming practices, weather conditions during crop growth, and the Köppen climate classification of the crop origin to better understand their impact on mycotoxin levels in feed.
Source: Science of the Total Environment
