Got fusarium? Turn to worms

Fiona Buchanan, an animal sciences professor at the University of Saskatchewan, holds up a heap of mealworms she scooped from a tub of fusarium-damaged wheat where they were feeding. Buchanan is researching the feasibility of cleaning vomitoxins out of fusarium-contaminated wheat by feeding the wheat to the worms.  |  William DeKay photo

Insects and disease are two enemies of the prairie wheat farmer, but researchers feel there is a unique case where one can help deal with damage inflicted by the other.

Researchers at the University of Saskatchewan have determined they can fatten up mealworms on a diet of fusarium-damaged wheat and then safely feed the mealworms to broiler chickens.

Fusarium head blight can be a major downgrading factor for wheat. For instance, in 2016 it caused an estimated $1 billion in damage to the prairie wheat crop.

Fiona Buchanan, a professor at the U of S’s agriculture college, wanted to do something about that.

“We wanted to give value to something that the producer was losing their shirts over,” she said.

Buchanan found her inspiration during a conversation with a seed cleaner friend who mentioned he heard mealworms could detoxify fusarium-infected crops.

“I basically came back to my office and looked that up because I like insects. My masters was in mosquitoes,” said Buchanan, who is a beef cattle geneticist in the college’s animal and poultry science department.

Buchanan and master’s student Carlos Ochoa decided to conduct their own experiment on feeding fusarium-damaged wheat to mealworms and then the mealworms to chickens.

Consuming fusarium-damaged wheat can be detrimental to both humans and animals above certain thresholds of contamination. In the case of chickens, the threshold is five parts per million of vomitoxin.

The researchers bought one tonne of fusarium-damaged wheat with a contamination level of eight p.p.m. of vomitoxin.

They separated the wheat into fractions that ranged from 0.2 p.p.m. to 12 p.p.m. of vomitoxin.

The mealworms were fed the contaminated wheat for 30 days and then fasted to get rid of anything in their gastrointestinal tract. The worms were freeze-dried, ground up and analyzed for toxins.

The worms contained 0.13 p.p.m. of vomitoxin no matter whether they were fed wheat with high or low doses of vomitoxin.

The mealworms were fed to broiler chicks that were at first bewildered by the feed ingredient, until their instincts kicked in and they started to fight over the insect larvae.

“It turned into an absolute feeding frenzy,” said Buchanan.

The results of the experiment were so encouraging she believes it could be the foundation of a novel poultry feed business.

Tim Keet, chair of the Canadian Poultry Research Council, said mealworms make an ideal feed for chickens and have been approved by the Canadian Food Inspection Agency.

“It’s something that’s very favourable because it’s actually a well-balanced protein, especially for the birds,” he said.

The worms contain 50 percent protein and 34 percent fat, so he thinks it would be an excellent product to kick-start growth in young hatchlings.

It is also a good dietary fit because mealworms are what chickens ate when they were in the wild.

“It’s very palatable,” said Keet.

Laura Reiter, chair of the Saskatchewan Wheat Development Commission, is also intrigued by the project because fusarium-damaged wheat can be a marketing headache for farmers in wet years.

Growers do everything from blending and cleaning their grain to burying it, depending on the severity of the infection. As a result, converting heavily damaged wheat into a useable feed would be a welcome development.

“Any market for a product that you can’t sell has got to be a positive, but it would just depend how much they could take,” she said.

Buchanan has done some rough math and determined that if Saskatchewan’s 29 million broiler chickens were fed a diet of mealworms, those worms could consume 250,000 tonnes of fusarium-infected wheat annually.

She said the goal would be to attract an insect-rearing facility to the Prairies that would buy fusarium-damaged wheat from farmers and infected screenings from seed cleaning plants.

She has fed those screenings, which can be as high as 95 p.p.m. vomitoxin, to mealworms and their flightless beetle parents, and it hasn’t bothered the bugs.

Reiter said the business would have to have a plan B for years like 2017 when fusarium wasn’t a problem, such as having a stockpile of fusarium-damaged wheat.

Buchanan and her growing research team have secured funding for a second experiment, where some mealworms will be fed fusarium-free wheat while others will consume wheat containing high levels of vomitoxin.

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