Why NZ farmers should hope for positive results from research into the methane effects of lacing stock feed with seaweed

A post on the Point of Order blog today reports on concerns about the contribution of methane to climate change and to the research in New Zealand and Australia to find ways of reducing methane emissions in farm animals…

A warning  bell  sounded  for  New Zealand farmers  when The Economist – in an editorial  last week headed “It  is  not  all  about  the  CO2” – argued  that carbon  dioxide is by far the most important   driver of  climate  change, but methane  matters  too.

The  final  sentence of  the  editorial reads,  ominously:

“Methane  should be  given priority on the  COP26 climate  summit  this  November”.

NZ may  fight  its  corner   vigorously   at the   Glasgow  summit,  but  the   risk is  that  delegates  there   will  seize  on  the  thesis  advanced  by The Economist    that   methane is  a more  powerful  greenhouse  gas  than  carbon   dioxide,  and  decide  to  target  it harshly.

 “Reduce  methane  emissions and  you  soon  reduce  methane  levels;  reduce   methane  levels  and  you  reduce global  warming”,  says The Economist.

With  NZ’s   greenhouse  gas  emissions  comprising  about 49%  methane, this  country  could  be  savaged  by  climate  change  warriors,  while other  countries  could  follow the  European Union  in  contemplating  a  tariff regime,  or  what  it  calls  a  carbon border  adjustment  mechanism  (CBAM),  in  which the  price  of  imports  reflect their carbon  content.    Such  a    mechanism, if  adopted   broadly, could severely penalise NZ  agriculture  exports.

So  the  search  has  begun  for  solutions to  the  problem  of  agricultural  methane emissions.

A  small group of  New  Zealanders see  the   answer  in  a  variety  of  seaweed called  Asparagopsis  that  reduces  the amount  of methane cows   burp  into the atmosphere.  Nelson’s Cawthron Institute is running a one-year research project, with $100,000 in government funding, to look at Asparagopsis’s preferred growing conditions.

The Provincial Growth Fund earlier awarded $500,000 to  a company, CH4 Global, which aims to grow and process the seaweed in NZ and South Australia. Both are working with Australian teams at research organisation CSIRO and James Cook University, who discovered that the fluffy native algae could reduce the amount of methane let off by farm animals.

On the face of it, the research looks promising.  Studies in both the lab and on live animals have found supplementing the diet of sheep and dairy cows with 1-3% of dried seaweed can reduce their methane emissions by 60-90%. But behind those numbers lie logistical, food safety and animal health questions.

Dr  Michael Lakeman,  chief  science  officer  of  CH4  Global,  speaks enthusiastically about the  work with  the  seaweed.  He  says  if you fed each of NZ’s dairy cows a tiny amount of it each day, this seaweed would remove as much greenhouse gas emissions as  by converting every vehicle on our roads to electric power.

Unlike humans, sheep and cattle can digest cellulose in plants. The first of their four stomachs – the oxygen-starved rumen – contains an army of micro-organisms that help ferment the feed, reducing it to smaller molecules that the animal can then turn into energy.

Among the microbes are methanogens, which like to hang out in oxygen-free spots.

They combine fermentation by-product hydrogen with carbon dioxide, to produce methane and water. The methane, or CH4, is released when the animal burps.

Unlike most microbes in the gut, scientists’ best guess is that methanogens are not essential to digestion, so if you could reduce their activity, you could reduce methane emissions without affecting the animal’s growth and health.

In the case of Asparagopsis, scientists have worked out that bromoform – a chemical found in many seaweeds – inhibits the methanogens, reducing  methane release.

Dr  Lakeman  says  results  of  their  work  have  been promising. They show that a tiny amount of Asparagopsis in the feed of beef cattle cut methane emissions by  98%, while leaving no residues in the meat.

These cattle also gained weight 50% faster than those that didn’t have seaweed in their feed.

“Results like this encourage us that Asparagopsis can be a game-changer for NZ’s livestock industries, even as we acknowledge there are still challenges to be overcome before that potential is realised”.

The  research   being  undertaken   into  the  seaweed   looks likely to come into  sharp  focus   if  COP26  leads  to   action   on  methane.   NZ  has  a chance  to  do things  differently,  providing  the  research produces  the  answers envisioned by people like  Dr Lakeman.

Dairy and meat that comes without a climate footprint will command a premium price.

Source:  Point of Order

Author: Bob Edlin

Editor of AgScience Magazine and Editor of the AgScience Blog