A Seaweed Diet Could Reduce Cattle’s CO2 Emissions

Green, red, or amber seaweed might turn to be the perfect new ingredient on the menu for cattle, while tackling the future of the environment, too.

Aside from their nutritious and richness of bioactive substances, researchers in the U.S. found that Asparagopsis taxiformis a red algae growing in the tropics,  can inhibit the development of methane in the stomach of cows up to 80%.

Cows’ burp is indeed polluting: according to the United Nations, it is responsible for 14.5% of the world’s annual greenhouse gas emissions. There are over 1.6 billion cows on earth: adding algae-based feed supplements within their meals could drastically diminish CO2 emission from beef production.

In the past two years, researches have started to look at introducing small quantities of seaweed in animal feed to see what is the potential digestibility and methane reduction of seaweed for cattle. A team of researchers at the University of the Sunshine Coast in Australia realized this back in 2019 after feeding asparagopsis taxiformis to cattle. Similarly at the University of California, researchers have just reached the same conclusion conducting a study that tracked methane emissions on cows for a time span of 5 months.

An European version

While this red algae is an indigenous plant within the tropics, alternatives exist in the European marine environment, too.

In 2019, the University of Copenhagen had started researches on a variety of algae present in the North sea among which Alaria esculenta, Ascophyllum nodossum and Saccharina lattisima. In order to assess the potential for methane reduction and digestibility, seaweed and seaweed products were tested at the fiber degradation and gas production laboratory. A consistent methane reduction of about 20% was observed, however far from the outstanding results performed using the red algae. 

According to the Danish Agriculture & Food Council local agriculture’s official emissions of CO2 and greenhouse gases amount to approx. 20% of Denmark’s total CO2 emissions, out of which 30% of the official agricultural emissions is methane from ruminant cows. 

From theory to practice

Reaching net-zero targets simply by changing cows’ diet is however far from possible. In fact, cattle ruminate in the open space for most of their lives, a period in which they would not be fed with feedstock, hence limiting the efficacy of algae supplement only to a relatively short time.

Other more creative solutions dedicated to decreasing cow’s burp have shown up. Probably inspired by the pandemic, earlier this year U.K. startup ZELP proposed burp-catching masks for cattle, to help neutralize livestock methane. 

But cows’ burp is only one of the many CO2 emitting items in the chapter of the beef industry. According to FAO, of the 263 million tonnes of meat produced globally, over 20% is lost or wasted, it seems reasonable to readdress attention to creating new food systems that divert from intensive farming practices, which could be effective in limiting CO2 emission.

Nevertheless, seaweed remains a very scalable solution to the climate crisis as seaweed farms release carbon that may be buried in sediments or exported to the deep sea, therefore acting as a carbon sink. As well, as farmland remains limited, growing sea-crops in the oceans and seaweed aquaculture is becoming the fastest-growing component of global food production.

Whether on cattle’s menu, fish feed or on our tables produce from seaweed production could offer opportunities to mitigate and adapt to climate change.