Ruminants are regarded as quite resistant to fusarium mycotoxins such as deoxynivalenol (DON) because of the detoxifying potential of rumen microbes. However, the detoxification capacity of rumen microbes depends on a functional rumen. Detoxification capacity for DON by rumen bacteria can be compromised in high producing dairy cows, which are fed greater amounts of concentrates and where feed passage rate is high.
Read more about how to best support them by nutritional means.
In “How cows can adapt to DON” published in Milling and Grain Magazine, September 2017, p 70-71 here