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Less Gas from Farm Animals

2002-5-23

This is the VOA SpecialEnglish Environment Report.

Scientists in New Zealand have found a way to reduce methanegases released by cows and sheep. The new study showed that feedingsome crops to farm animals can reduce methane gas by as much assixteen percent. Reports say the finding could help efforts toreduce greenhouse gases – harmful gases that cause warming of theEarth.

Methane and other greenhouse gasestrap heat from the sun in the atmosphere. Scientists say increasedtemperatures on Earth will have serious effects on the environment,plants, animals, agriculture and sea levels.

Sheep and cattle expel methane gas in their breath. The gas is aproduct of chemical processes in their feed. Sheep and cows are twomembers of a group of animals called ruminants. About ninety percentof New Zealand's methane gas releases comes from ruminants.

In New Zealand, the average cow produces about ninety kilogramsof methane each year. Reducing greenhouse gases is an important goalin New Zealand. It is one of the countries that must reduce itslevels of greenhouse gases under an international treaty called theKyoto Protocol.

Scientists Garry Waghorn and Michael Tavendale supervised the newstudy. They found that chemicals in some grasses can directly reducethe release of methane from sheep and cattle. New Zealand'sagricultural research center, AgResearch, reported their findings.

The scientists tested different kinds of plants in grasslandswhere the animals feed. They found that natural plant chemicalscalled condensed tannins have a major effect on the amount ofmethane produced. Condensed tannins are found in some grasses. Theyalso are found in apples, cocoa and wine, a drink made from grapes.The New Zealand team studied a legume plant, the lotus, whichcontains naturally condensed tannin compounds.

AgResearch notes the discovery is only the first step. It saysscientists will continue to investigate how diets containingcondensed tannins can be used to lower methane production in farmanimals. Scientists say condensed tannins also are helpful to farmanimals in other ways. They increase weight gain and milkproduction. They also decrease the risk of some diseases.

This VOA Special English Environment Report was written by GeorgeGrow.