New research hopes to reduce ruminant wind

New Zealand scientists have made a discovery that they say could see a reduction in methane production from cows, sheep and other ruminants by 16 %.

AgResearch, a body of researchers in biological sciences, say they have proven that pasture species containing condensed tannins, such as clover and lotus, can reduce these greenhouse gas emissions. Condensed tannins are naturally occurring compounds that are found in these pasture species as well as things like wine and apples.

With New Zealand’s largely agricultural based economy, it is estimated that 90% of the nation’s methane emissions are expelled from windy ruminants.

In trials by the researchers, sheep and cattle were fed pasture species with high levels of condensed tannins. They found less methane was produced per unit of feed from ruminants fed on such species than those fed on normal grass or feed that were void of tannins. The researchers claim that in plants such as lotus, half as much methane was produced by comparison to traditional feed, they also say that tannins reduce nitrous oxide release, another greenhouse gas.

Farmers in New Zealand are already implementing this research into their farming practices, Garry Waghorn, a researcher at AgResearch, told edie. Although species like lotus produce 20% less feed than grass, it provides farmers with many benefits for their livestock, other than reduced emissions, such as preventing bloating and worms.

This new research could be a big step forward for New Zealand reducing their greenhouse gas emissions, and subsequently meeting their targets under the Kyoto Protocol that dictates that they must keep greenhouse gas emissions below their 1990 levels (see related story). New Zealand is keen to avoid penalties under the Protocol for non-compliance, with the government recently proposing a carbon emissions taxing scheme to ensure carbon reduction targets are met (see related story).

“It’s early days, but this is very encouraging news,” commented researcher Dr Michael Tavendale. He said their discovery would offer New Zealand farmers’ positive opportunities to control methane emissions.

Action has been taken by other nations to reduce their methane emissions, with Ireland vowing to reduce their livestock by 10% by 2010 (see related story), whilst Australia has developed a methane map which tracks cow and sheep emissions over the country (see related story).

A single New Zealand cow produces 90 kilograms of methane per year, equivalent to 120 litres of gasoline.

Researches say the best way to use their discoveries is to graze ruminants on species containing condensed tannins either by sowing them in their land or introducing the tannin component into the traditional feed. A problem the scientist have is that they know some plants have the mechanical machinery to produce tannin, however they are not producing it in the most beneficial part, for example clover produces tannin in the flower but it would be of greater use to produce it in the leaves.

“This is a frustrating situation for us,” Waghorn commented “we need to find out how to get plants express the tannin component in more parts where they can be of greater gain.” AgResearch is confident that their work provides enough proof of the benefits of tannins to give incentive for funding agencies to provide money for research into ways to do this.

Story by Sorcha Clifford

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