Back in March, we shared the research findings from a University of California study on how feeding seaweed to cattle can reduce methane emissions from their burps and flatulence by up to 82 percent. Now, scientists in Scotland have found that the same effect holds true for sheep.
The recently published study involved sheep on the remote Scottish island of North Ronaldsay. Islanders on the five-km-long island always had limited space available for farming. As a result, they keep the sheep on the seashore.
During the summer months, there is enough grass to keep the sheep satisfied. But when the weather gets colder, the animals have to eat the island’s plentiful supply of seaweed to survive, which they do for months at a time.
In order to measure the effects of this unusual sheep diet, scientists at the James Hutton Institute in Dundee in easter Scotland have made the animals the subject of a two-decade-long study. They have discovered that the seaweed in their feed significantly reduced the animals’ methane emissions, which is about 30 times as effective in trapping heat as carbon dioxide.
How does seaweed reduce methane emissions?
Methane from livestock comes from enteric fermentation — a chemical reaction that occurs in the animals’ stomachs as they digest plants. According to the scientists, the seaweed diet had an effect on the digestive system of the Orkney sheep, resulting in reduced amounts of methane being produced, reports euronews.
“There are different components in the seaweed that actually interfere with the process (of) how methane is made,” explains a member of the team at The James Hutton Institute Gordon McDougall. “We need to absolutely prove: one, which seaweed is going to be the best for this, what amount of seaweed into the feed gives the best effect. And then, can you scale that up to a level where you’d actually have an effect on the overall UK farming.”
The marine plant — a rich source of minerals, vitamins, and omega-3 fatty acids — could also provide an alternative to soy, which is often used in the feed of farm animals. Soy animal feed typically travels thousands of miles before it ends in the stomachs of farm animals and is linked to deforestation.
Additional sources: ScienceDirect — The role of seaweed as a potential dietary supplementation for enteric methane mitigation in ruminants