Algae added to cattle diets reduces methane emissions by 99 percent.
An Australian red seaweed capable of significantly reducing methane emissions from cows. On the horizon is the solution to the problem related to the production of the gas capable of drastically increasing the greenhouse effect by contributing to overheating the earth and which is produced in large quantities by the digestion of animals, especially ruminants. Under the guidance of aquaculture professor Rocky De Nys, researchers have found that adding less than 2 percent dry seaweed to a cow’s diet can reduce methane emissions by 99 percent. (1)
The Australian study
The study (Breanna et al.) was conducted by researchers at James Cook University in Queensland, Australia, in collaboration with the Commonwealth Scientific and Industrial Research Organization (CSIRO), an Australian federal research agency.
Staggering numbers on the amounts of methane released by cows, considering that there are currently 1.3 to 1.5 billion ruminants roaming the planet.
Methane is about 25 times more potent than carbon dioxide over a 100-year period, and a single cow releases between 70 and 120 kilograms of methane per year. Gas from cows accounts for 26 percent of total methane emissions in the United States, a country that is only the fourth largest producer of cattle in the world, behind China, Brazil and India.
One breeder’s experiment
Researchers began studying the potential effect of algae on cows in 2005, when a dairy farmer named Joe Dorgan inadvertently conducted an experiment on his herd in Prince Edward Island, Canada. Dorgan noticed that the cows grazing on the kelp along the shore were healthier and more productive than those left in the field. He began feeding his cows a mixture of storm-rooted seaweed and found that the new diet saved him money and induced “more pronounced heats” and longer reproductive activity.
Algae in history
The beneficial properties of algae in farm animals were known to the Greeks who used this practice as early as 100 B.C. There are also accounts of Icelandic farmers using seaweed to keep their livestock healthy and produce greater amounts of milk.
A 2014 study by Canadian researchers Rob Kinley and Alan Fredeen confirmed the results of Dorgan’s experiment and also found that‘feeding algae and macroalgal products has been shown to reduce intestinal methane emission from rumen fermentation.’
In vitro testing
Kinley joined De Nys in Australia two years later to conduct further in vitro testing. The two researchers tested 20 different species of algae on bacteria found in the stomachs of cows and found that they reduced methane production by up to 50 percent, depending on the amount administered. But reducing methane to remarkable levels required high doses of algae, nearly 20 percent by weight of the sample. All this made it difficult to use a high percentage of algae outside the laboratory with adverse effects on the metabolism of the cow’s digestion.
The alga Asparagopsis Taxiformis
When researchers tested a species of red algae called Asparagopsis taxiformis that grows off the coast of Queensland, Australia, they found that it reduced methane production by more than 99 percent in the laboratory. It also required a dose of less than 2% to work effectively. After digestion, Asparagopsis produces a compound called Bromoform (CHBR3), which interacts with enzymes in ruminant stomachs and stops the methane production cycle before the gas is released into the atmosphere.
The turning point
In 2011, Dorgan sold his dairy to focus full-time on producing algae-infused cow feed. The company it is part of, North Atlantic Organics, uses traditional methods of algae production: hand-harvesting and solar drying to reduce its carbon footprint and ensure that the final product is free of additives.
Important hurdles remain to be overcome before the technique can be implemented on an industrial scale. The first: most dairy and beef operations in kangaroo country are located inland, away from the sea where the seaweed is. Second, it is necessary to produce enough Asparagopsis. More than 15 thousand hectares of seaweed farms would be needed to feed 10 percent of Australia’s dairy cattle. Spontaneous collection might work on an agricultural basis, but the practice becomes unfeasible on a large scale.
‘The main barrier to the use of Asparagopsis taxiformis? Have enough algae to feed millions of cows‘, Kinley said in an interview with the ABC, Australia’s main public broadcasting company, which is fully funded by the federal government.
Antonio Gattulli
Footnotes
(1) (1) Breanna M. Roque, Marielena Venegas, Robert D. Kinley, Rocky de Nys, Toni L. Duarte, Xiang Yang, Ermias Kebreab. Red seaweed (Asparagopsis taxiformis) supplementation reduces enteric methane by over 80 percent in beef steers. PLOS ONE, 2021; 16 (3): e0247820 DOI: 10.1371/journal.pone.0247820
Veterinarian and journalist. Specialist in inspection of food of animal origin
