Researchers explore ‘sushi factor’ for livestock

Agriculture Canada studies find that adding seaweed to animal diets results in new nutrition profiles for the meat

Seaweed, rich in micronutrients, could someday make it into the diets of cattle and other prairie-grown livestock.

“It’s like an additive approach that can supplement maybe some grains or whatever that will provide nutrients,” said Wade Abbott, research scientist at Agriculture Canada’s Lethbridge Research and Development Centre.

“They’re easily digestible, they’re loaded with protein and we’re getting around a lot of these other controversial aspects of feeding animals human crops or human foods.”

He said seaweed brings different nutritional properties to the table and it doesn’t need the use of arable land, fresh water or fertilizer. As well, it grows rapidly, some as much one metre a day.

Abbott and Alisdair Boraston from the University of Victoria helped determine how polysaccharides (a type of carbohydrate or sugar) in red seaweed are released when metabolized in the digestive tract of humans.

He said understanding how micro-organisms in the human gut use the sugars found in seaweed opens the potential to expand what is now a limited use of algae products.

In 2008, researchers made the sushi factor connection that the Japanese diet was enriched with the bacteria that actually digested the carbohydrates found in the cell walls of nori, which are the green sheets of dried edible seaweed called porphyra used to make sushi.

“It’s green, but it’s actually from a red algae, which is from a red seaweed,” Abbott said.

“Here you have this people group eating this material from the ocean and the gut microbiota has adapted. Researchers found a particular species that had enzymes that were designed to digest this seaweed polysaccharide.”

Armed with this information and using the crystallography beamline at the Canadian Light Source at the University of Saskatchewan in Saskatoon, the researchers were able to solve the structures of four different enzymes that digest agarose, a polysaccharide found in red seaweed.

“We were able to make some real progress and actually define all the major enzymes involved in the process of converting these seaweed glycans into sugars that can be metabolized for energy,” he said.

“So that really was, I think, a success story of this. We were able to really drill down and understand how this process is happening at the molecular level.”

While the study hasn’t actually validated the process in livestock animals, Abbott said researchers are now in a good position to look for related bacteria that will colonize the rumen across many species.

“What we find is the microbiomes of animal guts are just extremely diverse and you find that it doesn’t really matter what type of glycan you end up feeding these animals. There are bacteria and microbes in there that can digest them. So they may be at really low abundance but if you shift the diet, you see a shift in the community and that’s really something that’s become apparent to me in the last five years,” he said.

Further research of seaweed is also discovering other benefits, such as significantly reduced methane emissions.

“It’s a super food for sure and it has all these environmental benefits about where it’s produced and also the potential to maybe lower greenhouse gas emissions.”

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