Seaweed could thwart livestock methane emissions
August 15, 2017
Researchers find adding less than 2 percent dried seaweed to a cow's diet could reduce the animal's methane emissions by up to 99 percent.
Researchers in Australia have found an unlikely ally to help curb the methane released in cow burps and farts: seaweed.
Several varieties of seaweed are emerging as effective methane-neutralizers — but one, in particular, may reduce methane emissions from cows by up to 99 percent by adding a miniscule amount to the cow's diet.
This rapidly growing field of high-tech research has a farmy genesis.
In the mid-2000s, Canadian dairy farmer Joe Dorgan noticed a difference in his two cow herds. One produced more milk, had lower instances of mastitis, and higher conception rates. The only difference between the two herds was their pasture. The happier cows grazed on an ocean-front property, the others on a landlocked pasture.
Dorgan had seen his ocean-front cows graze storm-tossed seaweed and wondered if it had anything to do with their performance. So he schlepped seaweed inland to his land-lubber cows, and started to see the same health benefits his beach grazers enjoyed.
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Today, Joe Dorgan is out of the dairy business and in the seaweed business.
Before he could market his seaweed for livestock consumption, it had to undergo a thorough research process — and that's how Dr. Rob Kinley's career collided with seaweed. Kinley's research university was called on to review Dorgan's seaweed for livestock consumption. While he was reviewing seaweed's health benefits — he noticed something else.
"I had the ability to test the gas from ruminant fermentations," Dr. Kinley said. Right away he discovered gas production — methane specifically — was dropping by 15-20 percent where seaweed had been fed.
The United Nations' Food and Agriculture Organization estimates about 35 percent of methane emissions globally stem from agriculture. As the world comes to grips with climate change, the livestock industry has been under increasing scrutiny over methane emissions in recent years.
"I got it in my mind that somewhere in the world there's gotta be a seaweed with a bigger punch than those local ones," Kinley recalled. "I started on a global hunt."
That hunt led Dr. Kinley to Australia, where he and other researchers zeroed in on 20 varieties of seaweed to review for methane reduction when fed to cows and sheep.
The moment Dr. Kinley found what he was looking for, he didn't believe it.
"I wasn't seeing any [methane]. I thought the instrumentation was bogus. I did the test over again," he said. But the results were consistent.
One seaweed in particular, asparagopsis taxiformis, appeared to have nearly eliminated methane production in synthetic rumens in the lab.
Up until this point, most of the seaweeds Kinley's team evaluated were effective at reducing methane in proportion to how much cows were fed. In other words, the more seaweed you put in the rumen, the less methane was produced. Kinley said that had obvious practical limitations — like how you procure and feed livestock several pounds of dried seaweed per day.
With asparagopsis, subbing less than 2 percent of it into a cow's diet reduced methane emissions by 99 percent. Dr. Kinley calls it a "seaweed knockout punch."
The livestock industry has been quick to embrace Dr. Kinley's findings. The trade group Meat and Livestock Australia is a major funder of Kinley's research. The Irish Farmers' Association has called on Irish researchers to immediately evaluate Kinley's findings for the Irish livestock industry.
Researchers in the U.S., too, are cautiously intrigued.
If Dr. Kinley is the father of discovering seaweed's ability to curb methane emissions, then Dr. Charles Yarish of the University of Connecticut is the father of the American commercial seaweed industry.
And it's a burgeoning business. Worldwide, seaweed is a $7 billion dollar industry. The U.S.' seaweed sector is young, but growing.
Yarish says Kinley's miracle seaweed, asparagopsis, is not a species that lends itself to mass cultivation.
"There is no place on the planet its farmed," Yarish says. "It's not an easy seaweed to grow at the quantities needed. There's a whole host of technical issues with asparagopsis."
Yarish and a colleague at Penn State are presently courting funding to repeat some of Dr. Kinley's research stateside. They plan to focus on seaweed varieties that lend themselves to commercial farming.
"We've got to really search for those other seaweeds that we know can be farmed at the levels we're talking about," he says.
And to dig even deeper into the practical side of applying Kinley's research, there's the issue of how you get cows to eat seaweed in the right quantities.
Montana State University extension beef cattle specialist Rachel Endecott points out that cows emit varying degrees of methane depending on what they're eating.
"Cattle on feedlot diets actually produce less methane than cows on forage diets," Endecott says. Furthermore, "animals have the capability to select a higher quality diet when they're grazing."
Endecott points out that it can be difficult to get pasture-based cows to eat a uniform amount of anything. With self-fed supplements and minerals for example, there's a huge variability in which animals eat what.
"It's a lot easier to make sure every animal gets the same amount of something if they're in a pen-feeding situation," she adds, where methane emissions are already at their lowest.
Dr. Kinley agrees.
"Getting [seaweed] to grass-fed animals is a big problem," he says. "Most beef in Australia is grass-fed. A lot of these animals only see their producer a couple of times in their lifespan. So it's not easy to get them to eat seaweed." He points to feeding systems like dairies as a probable starting point for applying this research.
"Our biggest barrier is that we don't have this seaweed," he adds. "We're working on that."
He says more research is needed on how to apply his team's findings in a practical way. But he's committed to seeing it through. Early results have been too promising to abandon.
"Seaweed is an awesome thing. You can take this seaweed, you can grow it in impoverished areas and create a new economy in low-skilled labor. The seaweed remediates the [ocean habitat] where it's grown. And then you can bring the seaweed out of the water, feed it to cattle, get a bonus productivity enhancement by eliminating methane emissions in the animals eating it."
Kinley's team is about a third of the way through a feedlot trial involving daily seaweed rations in live cows. The results of that study are anticipated in October.