In our work, we conduct a research of mycotoxin contamination of feed for cattle harvested in 2022–2024. In total, we studied more than 260 samples of feed from a number of farms in the Vologda Region, and carried out more than 500 laboratory analyses of feed. The obtained results showed that almost all studied samples were contaminated with mycotoxins to some extent. The greatest degree of feed contamination of the studied mycotoxins is characterized by the sum of aflatoxins, so exceeding the maximum allowable concentration (MAC) of aflatoxins was detected in about 56% of samples. The next most important contaminant is ochratoxin-A, the share of samples with exceeding MAC is about 31%. Mono-species silages are the most affected by mycotoxins of all the feed samples studied.