Anne Hardie
Researchers estimate it will be three to five years to develop methods to grow the seaweed Asparagopsis armata sustainably so dairy farmers can use it to stop cows belching methane into the atmosphere.
Overseas research has already established that the seaweed can potentially reduce methane emissions from dairy cows and livestock by up to 80% and the Cawthron Institute in Nelson now has the task of finding out how to produce the seaweed on a mass scale and sustainably to feed to cattle in New Zealand and potentially global markets.
The native red seaweed grows abundantly throughout New Zealand waters and Cawthron’s group manager for aquaculture, Dr Serean Adams, says the initial feasibility study will be looking at onshore, inshore and offshore options and getting it up to scale as quickly as possible for further research.
This particular seaweed contains chemicals that reduce the microbes in the cows’ stomachs that cause them to belch when they eat grass.
Cows themselves do not produce methane, but microbes in the rumen do produce it from hydrogen and carbon dioxide as the feed breaks down. This particular seaweed contains chemicals that reduce the microbes in the cows’ stomachs that cause them to belch when they eat grass. About 90% of methane produced by cows come from those burps.
Much of the research with animals will be carried out overseas, such as FutureFeeds CSIRO in Australia, which is studying how much of the energy that would be otherwise lost as methane, will be conserved in the rumen and used for beneficial metabolism and converted into productivity and profit. Another question for researchers is whether the active ingredient in the seaweed taints milk, though Dr Adams says that has not been detected so far.
The goal now, she says, is growing enough of the seaweed sustainably and reliably to a standard it can all be validated, so researchers can go to the next step and explore more questions about feeding it to stock, such as finding the best form to get the active ingredient to the cows.
Overseas they have added it in small amounts to supplementary feed or put it in salt blocks, but she says there’s still a lot of work to be done on standardising the active ingredient.
“Very low amounts are needed – less than 3% (of dietary intake) and that really depends on the concentration of the active ingredient,” she says. “How can we prepare the seaweed in the best form to get the active ingredient to the cows? This research is about producing more so we can explore more of those questions.”
Cawthron’s chief commercial officer Stuart Cooper says nothing is seen as a silver bullet for reducing methane emissions, but Asparagopsis will provide another tool for the industry to use. Other research centres are working on breeding and vaccine development to reduce methane emissions.
“It looks very promising and there is the expertise there to develop opportunities,” he says about the seaweed. “The question is whether we can produce enough of it. It comes down to the amounts you use.”
The Cawthron Institute is contributing $150,000 toward the research and will receive $100,000 from the Sustainable Food & Fibre Futures Fund.
As part of the project, it will collaborate with researchers in Australia and the University of Waikato.
