20 µg/kg: Aflatoxin Limit for Contaminated Dairy Feed

In the Rhône-Alpes region, a transport tank detected positive for aflatoxins had to be destroyed, reussir.fr reported. The toxin, a toxic and carcinogenic mycotoxin produced by Aspergillus fungi, developed in maize crops following intense heat and water stress during the 2026 growing season.

Aflatoxin Contamination in Rhône-Alpes Maize Silages

Agricultural advisors in the affected zone report that the contamination originates directly from maize silos opened recently by farmers. While imported Nigerian soybean meal contaminated dairy farms in the Deux-Sèvres department in 2024, the current event stems from domestic field crops exposed to high temperatures. Béatrice Orlando of Arvalis explains that Aspergillus flavi fungi thrive under thermophilic conditions, with spore germination and growth peaking at 33°C. Although these fungi appear in roughly 80% of agricultural plots, toxin production occurs in only 0.5% to 7% of cases.

Mandatory Tests and Silo Dilution Rules for Dairy Farms

Livestock operations caught in the affected circuit must test whole-plant maize silage, grain maize, ear maize, and soybean meal for aflatoxin presence. Out of roughly 15 initial analyses, agricultural advisors note that while several returned negative results, specific maize samples tested positive. Under current regulations, feed exceeding 20 micrograms per kilogram of dry matter at 12% humidity must be banned from animal rations. Producers must also integrate mycotoxin binders into feeding routines and reduce the proportion of contaminated forage in dairy cow diets to dilute overall risk.

Financial Burden and Regulatory Pressures on Producers

France’s national mycotoxin observatory does not routinely screen for aflatoxins in maize because contamination typically remains rare. An observatory expert notes that zero out of 15 routine screening analyses have turned up positive so far this season. The discovery places heavy psychological stress on local farmers, who face strict legal obligations to sell milk meeting health standards without any anticipated state indemnification or insurance coverage for mycotoxin losses.

When dairy cows ingest contaminated feed, their livers convert aflatoxin B1 into aflatoxin M1, which is then excreted into milk and poses human liver cancer risks if limits are breached.