NZ Farmer - Cracking biological emissions from livestock a tough challenge

Written by Gerald Piddock

Scientists working on a vaccine to curb methane emissions among livestock have cautioned a working product is still some time away.

They hope to have a proof of concept by next year, but even if they achieved this breakthrough it would be no silver bullet, Pastoral Greenhouse Gas Research Consortium (PGGRC) general manager Mark Aspin told farming leaders at a Fieldays function.

The vaccine was one of the potential solutions the PPRC was researching which also included animal feeds, genetics and methane inhibitors.

It was a key puzzle to solve because 48.8 per cent of New Zealand's greenhouse gas emissions came from agriculture, of which 75 per cent was from methane and 25 per cent from nitrous oxide.

While some were at proof of concept stage, it was still a long way off from being a workable solution for farmers, he said.

"Proof of function is a completely different space."

The PGGRC was due to wind down next year. Its commitment to the government stipulated that it had to have tools farmers could use by that stage. If not, the only other solution for farmers would be offsetting their emissions through forestry or reducing herd numbers.

"If we kill the tools in the toolbox discovery programme, then we better start planting trees because that's pretty much all we are going to be doing."

If that occurred, that would result in significant land use change, Aspin said.

"None of these things are silver bullets, none of these will get to our goals in isolation, they are all components we are working on."

The consortium is funded by eight New Zealand agriculture partners and works with the government.

A vaccine was seen as a favourable option for lowering emissions because of its simplicity and it could be used regardless of farming systems.

The PGGRC  had been working on a vaccine since 2007 with the aim that it would bring about a change in microbes in the gut.

"It's proving to be a very hard nut to crack," he said.

Scientists thought it would induce an antibody that would circulate in the animal's rumen and stop or reduce the methane process.

Aspin said while there was no biological reason why it could not be done, they had yet to see a drop in methane via a vaccine in trials done so far.

"It sounds easy, but it's been pretty challenging."

One of the risks of inhibitor technology was that it had unintended consequences on animals. That was why any feed or a vaccine mitigation had to be studied over a long period.

PGGRC director Andrew Morrison also cautioned against the consequences of rushing out with a product before it was ready.

"It's one thing working with haste. It's another being kids running with scissors because the reality is that we have got to make sure we are delivering on something that is not going to create another problem down the track."