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The Silver Saliva Bullet

New Zealand researchers are hitting methane emissions from cattle with their best shot — a methane vaccine in the works that depends on… drool.

How to vax the rumen: Antibodies in a cow’s saliva ride through the digestive system, winding up in the stomach, where they bind to the pesky little methanogens that convert hydrogen into methane.

Getting enough of the antibodies in the rumen to be effective is the snag holding up the methane vaccine.

High gas bills: Test cattle have to be in full-body chambers that monitor gasses, but these chambers are expensive, costing up to $250,000.

A consortium of New Zealand livestock industry groups and the government have cost-shared the vaccine research, spending about $85M on R&D since 2003. They’ve dropped $4 to $5M a year since then on the silver saliva bullet.

Working around the clock: The New Zealand government aims to be the first nation in the world to fully fold agriculture into an emissions pricing scheme by 2025. The country accounts for about 0.16% of global emissions, half of which come from agriculture, and a quarter from dairy.