Tiny organism a big challenge to methane researchers

Much effort and intellectual grunt is going into solving the livestock methane emissions problem. Peter Burke reports on this science challenge facing New Zealand.

A TINY micro-organism one thousandth of a millimetre long is proving a huge challenge for scientists in New Zealand and overseas.

It's called a methanogen and it produces methane in the rumen of farm animals which they emit when they belch. That methane in the atmosphere contributes to the global warming now causing massive problems.

The agricultural sector accounts for 46% of New Zealand's emissions, a serious challenge given our large ruminant population.

New Zealand scientists hope within five years to develop on-farm technologies to help reduce methane gas emissions from cattle, sheep and deer.

The Pastoral Greenhouse Gas Research Consortium (PGgRc) and the New Zealand Agricultural Greenhouse Gas Research Centre (NZAGRC) are working to solve this problem. Their target is to lower emissions 5% below 1990 levels by 2020 and cut them by 50% by 2050.

One scientist working on methanogens is Dr Peter Janssen at AgResearch, Palmerston North.

Janssen says the rumen of animals is where feed is held and fermented by a complex community of different micro-organisms including methanogens. These live on the hydrogen gas that is a by-product of the rumination process; the methane they produce is no use to the animal so is expelled during belching.

"These methane producing micro-organisms are evolutionarily distinct from the other parts of this complex system including the ruminant animal. They are biologically different - promising if you are trying to develop a strategy to eliminate those without harming any other part."

Trouble is it's difficult to develop a vaccine or any sort of inhibitor, Janssen says.

The science challenge is underpinned by continuous investment by the PGgRc and NZAGRC, funded by the government and the primary sector.

Janssen says it takes a long time to build up knowledge and expertise in this area - a clear understanding of methanogens, in part by growing them in a laboratory.

Various scientific strategies are being worked on and trialled. These including breeding animals that produce less methane and studying different feed types for their effects on the amount of methane an animal produces.
Our scientists have bred animals that produce less methane. Various brassicas are found to reduce methane emissions, to a limited degree. Scientists are working on a vaccine and an ‘inhibitor' but a solution is still five years away.
Janssen says New Zealand researchers' contribution is significant and the quality of their work world class.

"Similar research is being done in Australia, Canada, to some extent in the US and some EU countries [but there is no] comprehensive programme. We have a programme of hedging our bets with low impact, low risk and high impact, high risk strategies.

"No one else has programmes applicable to our agricultural systems so we have to look after our own and make sure we develop things that work in our farming systems."

There is no guarantee a solution developed overseas would work in New Zealand given the unique nature of our farming systems.

Side Bar :pdf Breathe in, now breathe now (0.10MB)

Back to News