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Public acceptance of using genetically modified bacteria to reduce methane emissions of sheep

Find out what New Zealanders think about using genetically modified bacteria to reduce the methane production from sheep.

Methane is a greenhouse gas. It is produced in many industrial processes. It is also produced by bacteria living in the digestive tracts of mammals. What do New Zealanders think about using genetically modified bacteria to reduce the production of methane in sheep?

The methane problem

Methane makes up the biggest part of New Zealand's greenhouse gas emissions. It absorbs heat radiating from the earth and traps it in the atmosphere. This increases the temperature leading to global warming.

Animals, such as sheep, with an all-grass diet use bacteria that live in the gut to break down cellulose to get nutrition. This produces lots of methane. The gas collects in the stomach and is usually belched out. Sheep produce a lot of methane and are the main source of atmospheric methane in New Zealand.

By signing the Kyoto Protocol, New Zealand agreed to reduce the amount of its greenhouse gas emissions back to 1990 levels. In 1990, New Zealand produced 73 064 kilotons of greenhouse gases. Between 2008-2012 the government is bound to reduce emissions back to this level or take responsibility for any greenhouse gas emissions over and above this target.

Reducing the amount of methane emissions from sheep would help New Zealand meet these obligations.

A possible solution

Adding a different type of bacterium to the intestines of sheep could slow down the methane-producing bacteria, reducing the amount of methane produced. These bacteria could be introduced using a plastic device that would be inserted into the sheep's stomach.

The bacteria that would be used to do this job would be genetically modified.

What New Zealanders think

Focus groups conducted by Lincoln University's Agribusiness and Economics Research Unit (AERU) found that public opinion is divided over whether this application of biotechnology is acceptable or unacceptable.

The 117 participants wanted more information on how big New Zealands methane-emission problem is and what impact the genetically modified bacteria would have. They also wanted to know if the methane emissions from sheep could be reduced in other ways, such as through diet or sheep breeding.

Some people wanted to know what would happen to the bacteria - would they remain in the sheep and be incorporated into their meat or would they be egested along with their faeces? There was concern about the impacts of either of these scenarios. Another concern was whether this technology might become compulsory, and if it did, who would pay for it.

Some people thought introducing a different bacterium to a sheep's stomach was acceptable as long as the sheep weren't harmed by the device, it wasn't too expensive and it was easy to administer.

Others thought it was immoral to manipulate sheep in order to fix a problem that humans had created, and that it would be more responsible to reduce greenhouse gas emissions from industry.

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