Mon, Jul 19, 2010 page9

• How do you make a cow like a kangaroo?

  Researchers in Australia are looking for ways to eliminate the enormous amount of methane produced by cattle, and kangaroos might hold the answer

  • By Norimitshu Onishi / NY TIMES NEWS SERVICE
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  To hear Athol Klieve tell it, the key to reducing Australia’s enormous carbon emissions is to make cows more like this country’s most iconic animal — the kangaroo.

  Both animals are herbivores and both eat grass that is fermented before entering their main stomachs. But while cattle belch enormous amounts of methane to digest food, kangaroos release virtually none — they burp only harmless acids that can be turned into vinegar.

  Klieve, an expert on bovine stomachs, has fiddled around with the ruminants’ diet to make them less gassy. Little wonder then that on a tour of the new US$28 million Center for Advanced Animal Science here, he grew animated when talking about leading a team of microbiologists and genetic researchers to make cattle guts behave like kangaroos’.

  

  “Feed additives can lead to incremental decreases in methane,” Klieve said, standing inside a nearly complete high-tech chamber where cattle will be brought in to have their methane burps measured precisely.

  “But we’re trying to do other things that might give us a quantum leap, and that’s why we’re looking at kangaroos,” he said.

  Australia contributes more greenhouse gases per capita than just about any other country, with its coal-fired power plants leading the way. However, more than 10 percent of those gases come from what bureaucrats call livestock emissions — animals’ burping.

  At any given point, after munching and regurgitating grass, tens of millions of Australian cattle, as well as sheep, are belching methane gases nonstop into the air. With methane considered 21 times more potent than carbon dioxide at warming the atmosphere, the burping has given ammunition to environmentalists, vegetarians and other critics of beef while initially putting the meat industry on the defensive.

  Now the industry is fighting back. Along with the government, it is financing a US$24 million campaign to reduce burping. Researchers are looking at measures like adjusting diet, managing manure, recalibrating stomach organisms and selectively breeding animals that burp less.

  So far, the beef industry, led by Meat and Livestock Australia, and farmers have fought successfully against attempts to tax livestock emissions as part of a broader carbon pricing system. But in its push to curb Australia’s greenhouse gases, the government has pledged to put in place an emissions-trading system by 2013. In a country where growing environmental awareness could also hurt beef sales, Meat and Livestock is inviting leading environmentalists to seminars titled “Can Red Meat Be Green?”

  The question has cast a spotlight on a group of scientists more used to leading quiet lives of research, often peering through fistulas positioned on the sides of cows to give direct access to their guts.

  The scientists, rumen microbiologists — “We’re quite a few; you’d be amazed,” Klieve said — study the stomachs of ruminants like cows, sheep and deer.

  Ruminants release methane because of the peculiar way they digest their food. Inside a cow’s foregut, which can contain more than 90kg of grass at any given time, fermentation of the food leads to the release of hydrogen, a byproduct that slow down fermentation. Microbes known as methanogens help the ruminants get rid of the excess hydrogen by producing methane gases that the animals release into the atmosphere.

  In other animals known as hindgut fermenters, including humans — in which food is fermented after going through their stomachs — methane is sometimes released through flatulence, a fact that, Klieve said, has led to misunderstanding about his work

  “We’ve had to put up with that all the time,” Klieve said. “It comes from the front end! In the cow, it comes from the front end. But if you’re a hindgut fermenter, it goes the other way.”

  Leading a visitor through the campus here, which is part of the University of Queensland and is about 100km west of Brisbane, the state capital, Klieve explained his interest in kangaroos.

  Like cattle, kangaroos are also foregut fermenters. But instead of relying on methanogens to get rid of the unwanted hydrogen, kangaroos use different microbes that reduce hydrogen by producing not methane, but harmless acetic acids, the basis of vinegar. Could the microbes in the kangaroos be transplanted into cows? Could the right environment be created in cow stomachs so that the good microbes would outcompete the methanogens?

  “If we can answer those questions, we’re moving toward being able to get it so that these animals are not producing methane,” Klieve said.

  Not everyone supports the research. Some conservationists question trying to make a cow act like another animal.

  “This sounds surprising to me, that should be the primary focus when there is already an animal that does this,” said George Wilson, the leader of Australian Wildlife Services, a wildlife management company.

  Instead, Wilson has been urging Australians to eat kangaroos. He has proposed managing pastures to increase the harvest of kangaroo meat as an alternative to beef. His proposal was cited favorably in a major government report in 2008 on climate change, which pointed out that kangaroos had been the main source of meat for Australia’s Aboriginal people for 60,000 years.

  Currently a niche product, kangaroo meat “could again become important,” the report said.

  Beverley Henry, who is in charge of climate change issues at Meat and Livestock Australia, said kangaroos, which are culled from the wild and cannot be managed like livestock, could never become a main source of meat.

  “It’s going to be very difficult to meet the current production needs, particularly for the current global population, with kangaroo,” Henry said. “You need something like 10 kangaroos to produce the same amount of meat as one steer. You can’t herd them or fence them in.”

  Undaunted, a few kangaroo meat entrepreneurs are pressing ahead, seeing methane emissions as a business opportunity.

  Sharyn Garrett, whose family runs a kangaroo harvesting business in central Queensland, led efforts to form a cooperative to better promote the meat. Garrett recently won the Queensland Rural Woman of the Year award from a rural women’s network for her work with the cooperative and for a business proposal to raise the appeal of kangaroo meat.

  “We’d look to develop a strategy around how we can promote kangaroo meat as an alternative, or as a greener, more environmentally aware product,” Garrett said.
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