Research on Seaweed as a Cattle Feed Additive to Reduce Methane
Published on Wed, 12/08/2021 - 2:28pm
Research on Seaweed as a Cattle Feed Additive to Reduce Methane.
By Heather Smith Thomas.
With the push to reduce methane gas production (and other greenhouse gases such as carbon dioxide, as a way to combat climate change), a lot of attention has been focused on cattle—since methane is produced in the rumen by microbes that ferment feed and break it down into nutrients. Fermentation digestion generates byproducts that the cow’s body does not use, such as carbon dioxide and hydrogen. Methane-producing microbes, called methanogens, use these compounds to form methane gas, which the cow expels.
Researchers and startup companies have recognized the enormous opportunity associated with addressing the cow methane issue by changing their diet and are working on feed additives to reduce methane emissions from cows. Several startup companies are racing to offer options for farmers, using natural additives. There are already some synthetic additives on the market for methane reduction, but those cannot be used by organic farmers.
Blue Ocean Barns is one of two companies working with Asparagopsis taxiformis, a red seaweed. Blue Ocean Barns’ trials at the University of California, Davis and other peer-reviewed studies on this type of seaweed have shown that a small amount added to the cow’s diet can reduce methane emissions 50 to 90%.
Blue Ocean Barns has been growing seaweed for three years on an oceanfront property in Hawaii. It plans to have products available by the end of 2021, focusing first on California, where farmers are mandated by law to reduce methane emissions and where the company already has connections through UC-Davis.
In Hawaii, another company called Symbrosia is also working on growing this type of seaweed. To get certified by the Food and Drug Administration, it will need enough product to run a full commercial trial, however.
Alltech already has a product called Yea-Sacc that is commercially available. This is a yeast culture of Saccharomyces cerevisiae, and it does not directly reduce methane gas production. Instead, it increases the efficiency of milk production. Adding this yeast to the diet creates a healthier gut microbiome, allowing the cow to turn forage into milk easier and quicker. Alltech says Yea-Sacc provides higher sustained milk production per cow, therefore reducing the greenhouse gas emissions per unit of product. This approach might just lead to more efficient cows and methane production could remain stable.
Mootral is a Swiss agriculture company that has developed a garlic and citric acid natural feed supplement. The allicin in the garlic (the oily yellow liquid that gives garlic its unique odor) and the citrus extract in orange inhibit methane production in the rumen by as much as 23%, according to a UC-Davis study. Seaweed additive might have better methane reduction rates, but may still be a few years away from production. Mootral claims it has an advantage because it can tap into an existing supply chain within the current garlic industry.
Seaweed seems to show the most promise for the future. Research in several countries has shown that various types of seaweed can be fed to cattle, altering the chemical process in the rumen and reducing the amount of methane that is belched out. A number of studies are trying to determine which kinds of seaweed might work best.
Dr. Jennifer Smith (Professor of Marine Biology at Scripps Institution of Oceanography, University of California-San Diego) became interested in methane-mitigating feeds after seeing the original research done in Australia by government scientists who were looking at microbes extracted from ruminant animals. “They were experimenting with different additives to explore what might potentially reduce methane production in the rumen,” she says. The microbiome in the rumen is responsible for helping break down forages and other feeds.
“It’s much different working with bacteria in a petri dish compared with the live animal. This type of research has been going on for quite some time, and there are already some products available that have limited methane reduction potential. Other plant extracts have been tried, such as oregano and garlic, and various citrus products. None of them, however, have yielded anything substantial,” says Smith.
“The trial in Australia was looking at many different species of seaweed. The reason seaweeds are of interest is because they produce many interesting chemical compounds. They have lived in the ocean for millennia and have evolved many ways of dealing with bacteria and infections and other stressors; they have some fascinating chemistry,” she explains.
In this trial there was one particular species of seaweed that stood out above all the others in terms of high reduction of methane production. “This species is the red algae known as Asparagopsis taxiformis, and after that study was published in 2016, a number of livestock scientists became interested in testing this with live animals. This led to some of the first studies and publications at UC-Davis, by livestock scientists. They were able to feed cattle some of the dried, powdered seaweed,” says Smith.
The first trial was a dairy trial, feeding the seaweed for 30 days. “They were able to show remarkably consistent results in live animals--about 80 to 90% reduction in methane--just by feeding very small amounts.” In this study the seaweed fed was only about 1% of the total dry-matter intake, and subsequent studies have fed as low as 0.25% and still show significant methane reduction.
In these first dairy trials there were also some blinded taste tests to evaluate milk quality, and health statistics, and the scientists found nothing negative resulting from feeding the seaweed. Subsequent trials included a beef trial and that one was for nearly a year. That study was published in early 2021 and showed consistent and substantial methane reduction over time—with no loss of health in the animals or quality in the meat.
“The live animal trials have also shown that feeding seaweed makes the animals more feed efficient. Methane is a waste product (from digestion breakdown), and this carbon-based molecule is no longer being released as waste--so the carbon can be used in the animal’s metabolism. This is an added benefit for the farmers who are considering feeding a seaweed supplement.” If the cost of the supplement is offset by the fact that you don’t have to feed the cows as much total feed, it’s a win-win.
“Those studies have been published and there are other studies being published with sheep and other animals in different parts of the world, with very positive results. When I was first learning about this I contacted the scientists at UC-Davis and asked if they were working with any marine biologists on figuring out how to grow and commercially cultivate the seaweed. At that time there was no one in the U.S. working on that aspect,” says Smith.
Her PhD is in marine botany so she is very comfortable working in this phase of the research. “We wanted to figure out how to cultivate this seaweed in captivity. We have to get it from the ocean, isolate and purify it, and reduce all the other little organisms that might be attached to it or associated with it—and then get it growing in a land-based cultivation aquarium facility,” she explains.
“Then we needed to determine how to grow it the fastest and produce the highest-quality material. The reason this particular seaweed is such a stellar performer in methane mitigating is because it produces a host of compounds in higher quantities than in any other seaweed known. These compounds can vary a lot, however, even in this one type of seaweed, so we are trying to figure out how to manipulate the seaweed in a way that will produce the highest concentration of these compounds. This will ultimately affect the amount of seaweed we need to produce in order to feed a large number of cows,” she says.
“My lab has been working for the past 2.5 years trying to do all the science that will be needed to start a new commercial crop. If you think about when people first started growing wheat, corn, soybeans or any other crop, those didn’t pop up overnight. There is a lot of basic science that’s needed to better understand this seaweed; no one has closed the life cycle of this seaweed in captivity. We can grow it and we have a pretty good idea of growth rates and production potential, and we know a bit about how to manipulate the concentration of these compounds, but in terms of strain selection, etc. there is still a lot of work to be done,” she explains.
There is already a global seaweed aquiculture industry. Some seaweed crops are quite large, such as the seaweeds grown for sushi. “There are huge farms for that, in Asia. But the potential market size for this red seaweed (for livestock feed) and the interest we are seeing from the meat and dairy industries has the potential to be really big. We need to figure out how to scale it, fairly quickly, especially with all the greenhouse gas reduction policies that are going to be upon us soon. Methane only persists in the atmosphere for about 10 years, whereas carbon dioxide stays in the atmosphere much longer, but if we can work this angle and get this product on the market and get livestock consuming it, we could see a significant reduction of methane our lifetime,” she says.
This is an exciting solution for the livestock industry, and it only takes a tiny bit of the supplement to make a big difference. “There are a number of start-up companies around the world that are trying to commercialize this. It’s always a race to be the first to market with something like this. It’s highly unlikely that any one company will be able to supply enough seaweed for the entire world, so different parts of the world will likely utilize different strategies, depending upon conditions in particular regions, the permitting requirements, access to seawater, etc.”
Smith is working with one of these start-up companies, based in Hawaii. “That company is Blue Ocean Barns. They are using the results of some of my research in their commercial farm development. I’m helping them solve problems as they do things on the ground, and over time we hope to improve and increase their production potential and strain performance,” she says.
“There are also some groups in Australia, New Zealand, Europe and Southeast Asia that are also working on products,” says Smith. “There are still a lot of questions, but the research done so far has shown no detectable changes in the quality of the meat or dairy products from the cattle that consume the seaweed. If anything, there has been improved health and well-being of the animals and their feed efficiency,” she says. This may help make the livestock industry more sustainable and meet the growing demand for reduction of greenhouse gases.
Research In Canada
A number of studies have been trying to determine which kinds of seaweed might work best. One study was recently completed by Drs. John Church and Spencer Serin at Thompson Rivers University in Kamloops, British Columbia.
With the extreme heat and dry conditions this year in western Canada (and many animals dying from heat stress), people are becoming even more concerned about climate change. “I’ve talked to several experts who feel that in the future we may be more concerned about methane than carbon dioxide just because methane is accumulating at a faster rate, with a greater impact on the environment,” he says.
“Thus it makes sense to try to reduce production of methane. There is now a tremendous amount of excitement about seaweed,” says Church. He did a 2-year trial with seaweed as a feed supplement, feeding red algae seaweed from the West Coast.
Two cattle producers, Charlie Lasser and Edgar Smith fed it to their cattle for this trial. The cattle were divided into two groups. One group was fed seaweed and the other group were not, for two years. A testing apparatus in the form of a specialized feeder measured the methane that was burped out of the cows.
Preliminary information from the trial showed different types and amounts of bacteria in the cattle that were fed seaweed versus those that weren’t. The fascinating thing was that the animals were gaining more weight when fed seaweed. It improved their feed efficiency. The levels of fatty acids like CLA, omega 3, omega 6, etc. (factors that provide the health benefits of grass-fed beef) were changed, along with better feed efficiency.
The amount of methane reduction wasn’t as much as hoped, however. “We did not see as much reduction, in our trial, as was seen when using other species of seaweed. Now, the biggest focus in most research is on a species called Asparagopsis taxiformis, another type of red seaweed. The University of California at Davis has gotten really good data on the benefits of this kind of seaweed, and so has research in Pennsylvania and Australia. Those trials have been showing tremendous reductions in methane, in the live animal,” says Church.
Many studies have shown reduction in methane in vitro (rumen models) but not as many have shown results in live cattle. “The results in the lab don’t always relate to what is seen in the live animal, but several studies are now showing large reductions in methane, when feeding seaweed to the live animal,” he says.
The challenge right now is the life cycle of the species that has been identified as effective. “This type isn’t that easy to cultivate and grow, so most of the researchers have just been harvesting it (where it grows wild, in the ocean). They hire divers to go out and pick it by hand. We can, however, grow seaweed very effectively by using two buoys and a rope between them. You can seed the rope and it will grow seaweed on the rope, and then you just reel in the rope and cut off the seaweed,” he says.
“If we could find the right species to grow in the ocean, it would serve several purposes. There is a lot of carbon dioxide dissolved in the water, and aquatic plants can actually take up the carbonic acid and absorb some of that CO2 in the ocean. We can sequester carbon 5 to 10 times more efficiently with aquatic plants than with land plants. The advantage to storing carbon in those aquatic plants is that they are not at risk from fire!” We try to store carbon in forests and grasslands, but on a dry year these may be at risk for destruction by wildfires.
In the ocean, that risk doesn’t exist. “There are some CO2 extraction plants to pull it out of the air, but these are really expensive. It is a lot more efficient to do it in the ocean. If we can get the right species of seaweed to grow as a feed additive, it can serve two purposes,” he explains.
Seaweed is easy to grow; it only needs about 1.5 feet of water. “The seaweed is also very benign and doesn’t have a negative effect on the ocean. If we could grow a lot of it, this would actually help cool the ocean. The ocean is continuously warming. The atmosphere fluctuates more; the ocean temperature is a lot more steady, but gradually increasing. By growing more seaweed in the ocean, we can cool the ocean, and if we remove the carbonic acid that dissolves CO2 in the ocean, this would help all the shellfish and coral reefs, since excessive CO2 dissolved in the water is causing them trouble,” he explains.
“Cultivating seaweed might be the best thing we can do to combat climate change, and then the next question is what to do with all of that seaweed. Some people have suggested sequestering it at the bottom of the ocean, but I’ve never been a big fan of sequestering carbon dioxide in the soil or in the water because it seems to always find a way to get released and come back—but not if cattle eat it. If cows can eat that seaweed, we can reduce methane emission from cattle by 75% or so,” he says.
“With the local strain that we were feeding, our data (and data from other trials) showed additional benefits—antimicrobial and probiotic effects, which lend themselves to better feed efficiency. The Japanese, in their production of Wagyu beef, traditionally fed seaweed to their cattle,” he says.
It takes only a small amount of seaweed to get huge biological effects in cattle. We need cattle to graze the land that can’t be used in any other way to produce human food—and if we don’t graze it, there’s risk of burning up that unused forage. There are many benefits of having cattle and other large herbivores on the land. This was always the natural situation—with millions of bison grazing in North America, and other grazing herds of ruminants on other continents, and they’ve always been big contributors of methane into the atmosphere.
There are more cows today, however, than the number of bison or other wild ruminants in pre-historic times. There is tremendous potential to use cattle to reduce risk for wildfires (and fireproofing many communities) as well as for producing meat. Cattle are a very necessary part of our lives and we can’t have sustainable agriculture without manure. So if we can find a way to feed cattle a little seaweed, this would be a win-win situation.
“Our research group was not very successful with the initial species of seaweed we used in reducing methane, but there are hundreds of other local strains on the west coast that we still need to look at. We have a future project with a company on Vancouver Island, to test a lot more strains to feed cattle. We’d like to find a local species that is like Asparagopsis taxiformis in reducing methane, yet easy to grow.”
One thing Church found surprising, with the seaweed strain he used (Mazzaella japonica) was palatability. The cattle readily ate it. “The problem with Asparagopsis taxiformis is that cows don’t like it. You have to dry it and powder it and lace it with molasses so they’ll eat it, whereas we found no palatability issues with the species we used. I could feed it to cattle right out of my hands. If we could find a more palatable species that works to reduce methane, and is easy to cultivate in the ocean, this would be a solution.” Another challenge is that the bioactive components are volatile and require special processing and handling to ensure consistent methane-reducing properties.
Seaweed offers a multi-factored solution to climate change, not only reducing methane from cattle, but also potentially sucking up carbonic acid out of the ocean, simultaneously cooling the ocean and protecting the coral reefs and shellfish (to keep their shells from dissolving). It would definitely be a big win-win.
Feed Additive Approved In Brazil And Chile
There are some other potential feed supplements (besides seaweed) that can reduce methane production in ruminant animals Cattle producers in Brazil and Chile will soon be the first to gain access to a new methane-reducing feed additive created by a Dutch feed company (Royal DSM) after successful trials in Australia. Regulative authorities in Brazil and Chile have granted approval for the sale of a feed additive called Bovaer--for beef and dairy cattle in both countries.
This product performed well in beef cattle trials in Australia, reducing methane emissions as much as 90%. The research for this new product, known as Project Clean Cow, took more than 10 years, 45 on-farm trials in 13 countries across 4 continents, and has had 48 peer-reviewed studies published in independent scientific journals.
A beef trial with Bovaer at Sao Paolo State University in Brazil conducted in 2016-2017 showed methane emission reductions up to 55%. São Paulo State University professor Ricard Reis said the supplementation with Bovaer was an efficient strategy to reduce methane emissions by finishing feedlot beef cattle, without adverse effects on performance.
The product is created by combining nitrate and a bio-based alcohol. Just a quarter teaspoon of Bovaer per cow per day consistently reduces enteric methane emission by approximately 30% for dairy cows and up to 90% for beef cows. After suppressing methane production in the stomach, it is broken down into the same natural compounds again, which are already present in the cow’s stomach and processed by the cow’s normal digestive and metabolic processes.
The company is now trying to get permission to market the product in the European Union, New Zealand, and the U.S. and are expecting to get market approval in the E.U. later this year.