Late harvest caused higher mycotoxin threat in feeds

Mycotoxin levels were low in early samples of feed harvested in Western Canada. Then things changed.

Toxin levels are largely driven by weather, said All-Tech feed expert Dr. Max Hawkins. Rain in the later harvest season across much of the West opened the door and mycotoxins inched their way in.

He advised producers to test feed that was harvested later in the season to ensure it is safe for livestock consumption.

Depending on the species of livestock and the type and level of mycotoxin, feed contamination can cause digestive disorders including vomiting, intestinal damage and altered rumen function. Mycotoxins can also suppress immunity, lower pathogen resistance and lead to greater need for veterinary care.

“Immune health is a huge area that we worry about in terms of making the animal more susceptible… to pathogen loads,” Hawkins said in a webinar organized by All-Tech.

Delayed maturity, altered heat cycles and infertility or poor conception are further potential problems, as is reduced growth and lower egg, milk and meat output.

“The Number 1 most influencing factor in… moulds and mycotoxins is weather, and weather determines which moulds we’re going to have, the amount of those moulds, and then those moulds would determine if we go ahead and have which variety of mycotoxins.”

Fusarium can result in production of deoxynivalenol, commonly known as DON, for example, and fusarium thrives in wet conditions and moderate temperatures such as those seen across much of Western Canada in the late stages of harvest.

Hail and wind that cause crop injury also predispose the crop to high infestations of mould and mycotoxins, Hawkins added.

The timing of heavy rain is also a factor. Research shows heavy rain after the boot stage or at heading and flowering leads to higher incidence of DON. Heavy rain that occurs before those crop stages is more likely to result in T-2 and HT-2 mycotoxins, both of which can stem from fusarium.

Feeds that contain more than one mycotoxin are more challenging to animal health.

Results from feed tests in Western Canada show a higher risk of issues in an area around Red Deer, as well as small pockets near Brandon and Winnipeg.

Early harvested grain has low risk, said Hawkins, but grain harvested later should be tested before providing it to livestock.

He added that individual tests on feed are needed rather than relying on what the neighbour’s test revealed.

All-Tech’s website,, has more information.

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