The search for methane solutions

Several methane-lowering approaches are emerging:

■ Sheep that emit less methane have been selectively bred by the Pastoral■ An AgResearch-developed genetically modified ryegrass could potentially reduce methane and is being field-tested in the US but has not yet proceeded to animal trials.■ Fonterra is working on Kowbucha, a fermentable culture to switch off methanogens by adjusting the rumen’s microbe population.■ Dutch company Royal DSM has developed Bovaer, which it intends to apply to register here as an inhibitor. The compound’s 30% knockdown of methane emissions in feedlot systems is well established, but it isn’t in commercial use. A slow-release version for pasture systems is nearing completion.■ Mootral is a Swiss garlic-and-citrus extract in limited commercial use. Trials indicate it cuts methane in feedlot animals by 20-30%.