NZ has assured the world it will reduce its greenhouse gas emissions to agreed levels. The two problem gases for NZ are methane and nitrous oxide.
Methane inhibitors have the potential to reduce methane production by about 30%, so their widespread use by farmers would help reach the targets.
However, with NZ livestock eating grass 90% of the time, there are challenges to realising this potential, including how the inhibitor would be given to animals and ensuring the economics stack up.
To help clarify the subject of farm greenhouse gas emissions, the farmer-supported Pastoral Greenhouse Gas Research Consortium (PGgRc) and NZ Agricultural Greenhouse Gas Research Centre (NZAGRC) have developed a series of fact sheets. The most recent focuses on methane inhibitors.
How is methane produced? An animal’s rumen is essentially a fermentation vat containing microbes that play a role in fermentation. One of those microbes is methanogen, but methanogens are not essential to the animal, in fact, they are opportunists. They use hydrogen gas, a by-product of fermentation, and combine it with carbon dioxide to produce methane and water. The methane is then released into the atmosphere when the animal belches.
How does a methane inhibitor work? Scientists have identified chemical compounds that prevent the methanogens from working, shutting down the process of methane production.
A Swiss company has developed an inhibitor that works in a feedlot system, where it can be mixed with feed and consumed continuously. However, this isn’t practical in NZ’s pasture-based system.
A practical delivery mechanism is therefore one of the challenges. Options such as bolus capsules are being investigated.
How long until farmers can buy inhibitors? Conversations with potential commercial partners are underway. However, testing to rule out any impact on animals’ health, welfare and productivity needs to be done, so does ensuring there are no residue or food safety concerns.
All going to plan, commercial release is expected sometime after 2023 and the technology should be applicable internationally.
