Scientists say it could be five years before farmers can use newly discovered methane inhibitors to reduce greenhouse gas emissions from their stock.
The compounds were first tested in laboratory experiments in rumen fluid. Photo: RNZ / Veronika Meduna
AgResearch scientists searching for ways of reducing methane from livestock have identified five compounds that may prove effective in curbing New Zealand's biggest single source of greenhouse gas.
Initial short term trials show the compounds can reduce methane emissions from livestock by up to 90 percent.
The announcement was made to more than 100 researchers, farmers and lecturers at the Agricultural Greenhouse Gas Mitigation conference in Palmerston North yesterday.
Dairy NZ sustainability leader Dr Rick Pridmore said it would take time to work out how best to use the methane inhibitors because different techniques applied to different industries.
"A drench is one option; it's probably the more common option a farmer is used to," he said.
"Farmers don't typically use vaccines or have had used vaccines as much.
"I think that feeds is probably the better option because a farmer can plant a crop, know that once it's planted the animals can graze it and they might get some reduction.
"That's a very good option for a farmer, it's very simple to do."
Dr Pridmore said vaccines would have the advantage of being available for sheep, beef, dairy and deer.
Federated Farmers vice-president Anders Crofoot said while it was an exciting first step, only long-term testing would show the results - and he was not holding his breath.
"In some of the other research that's been done, they've had initial results and it does work for a short period of time - the rumen may then adjust and something else fills that void," he said.
"But if they can actually take something like methane production ... If it turns out that energy, instead of going off in methane, can actually be re-partitioned into producing protein, that will be a huge win-win."
Mr Crofoot said there were a range of factors to take into account.
"Whether there are side effects or co-benefits and then how it might actually be delivered into an animal's rumen and then what the costs are... If it turns out that it's hideously expensive to introduce to the animal then it won't be all that attractive."
Pastrol Green House Gas Research Consortium manager Mark Aspin said the methane inhibitors were just one part of a four-pronged approach to reducing emissions.
He said the ultimate goal was finding a long-term way to knock methane production.
"There has been work going on in breeding and also in finding low greenhouse gas feeds - and the fourth one is the development of a methane vaccine," he said.
"Across the board we've progressed in all of those. We now believe we've got solid evidence for heritability in sheep for the breeding that we hope to advance into the industry in 2016/2017.
"We're also now picking up from our learning in sheep to do some work in cattle and in deer to take that breeding approach, which is common to all livestock farmers, into the industry over the next five or so years."