Genetics

16 November 2009

Cloned cows on the menu

The use of cloned animals on farms is growing in popularity, and many claim that this breeding technology is at the forefront of a new era in animal agriculture.

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To the untrained eye, Pollard Farms looks much like any other cattle ranch. Similar-looking cows are huddled in similar-looking pens. But some of the cattle here don't just resemble each other. They are literally identical -- clear down to their genes.

Of the 400-some cattle in Barry Pollard's herd of mostly Black Angus cattle there are 22 clones, genetic copies of some of the most productive livestock the world has ever known.

Pollard, a neurosurgeon and owner of Pollard Farms, says such breeding technology is at the forefront of a new era in animal agriculture. "We're trying to stay on the very top of the heap of quality, genetically, with animals that will gain well and fatten well, produce well and reproduce well," Pollard said.

Most people’ eating cloned meat and don’t know it’
The US Food and Drug Administration in 2008 approved the sale of food from clones and their offspring, stating the products are indistinguishable from that of their non-clone counterparts. Japan, the European Union, and others have followed suit.

The moves have stirred controversy about whether tinkering with nature is safe, or even ethical, prompting major food companies to swear off food products from cloned animals. But consumers are likely already eating meat and drinking milk from the offspring of clones, which are technically not clones, without even knowing it.

Improved genetics means savings for farmers
Farmers can now use cloning and other assisted breeding technologies to breed cows that produce bigger, better steaks or massive amounts of milk, and animals that resist diseases or reproduce with clockwork precision. Premier genes can translate to improved feeding efficiency, meaning the ability to convert the least amount of feed into the most meat or milk, which results in a smaller environmental footprint.

"If you don't need as much corn to feed your cattle, you might be able to cut back on the amount of fertilizer put out there on the countryside that might end up in a river. You can cut the amount of diesel that's spent raising that corn," Pollard said.

"Just like they improve the genetics of corn, so they can produce more bushels per acre, we're trying to do that same type of thing by using cloning and superior genetics to produce more meat with less input."

Food production needs to double
The United Nations' Food and Agriculture Organisation has said food production will need to double by mid-century to meet demand from a growing world population, with 70% of that growth coming from efficiency-improving technologies.

Such forecasts have prompted calls for a second Green Revolution, a rethinking of the movement championed by Norman Borlaug, who won the 1970 Nobel Peace Prize for his work in boosting grain production for starving nations.

Biotechnological advances in grain production will remain at the forefront of the global fight to alleviate hunger, although animal agriculture will likely contribute in the longer term.

"When people talk about feeding the world, reducing or eliminating hunger, I don't think animal agriculture has much of a role to play. But, as people successfully move out of that extreme poverty, that's when you get the growth in demand for animal protein and, potentially, cloning could have positive benefits," said Robert Thomson, professor of agricultural policy at the University of Illinois.

Some animal breeds, ideally suited for arid climates, could be propagated to utilize grazing pastures unsuitable for crop production. Others may be bred to resist local maladies, like the Nguni cattle breed, which can develop resistance to ticks and immunity to tick-borne diseases.

Consumption on the rise
Meanwhile, a growing and more affluent population in the developing world is seen boosting demand for meat and dairy products. Meat consumption in developing countries more than doubled from about 10 kilograms per person per year in the 1960s to around 26 kg near the turn of the century, according to the FAO. By 2030, that was expected to rise to 37 kg per person. Milk and dairy product consumption has made similarly rapid growth.

Supporters say cloning will no doubt play a role in accelerating production, but the technology has been slow to take, primarily because of the high cost and resistance on ethical grounds. Of the more than 2.4 million Angus cattle that have been registered with the American Angus Association since 2001, only 56 were clones, according to Bryce Schumann, the group's chief executive.

How the cloning is done
The most common cloning technique is called somatic cell nuclear transfer, a process in which a donor egg cell's nucleus is removed and replaced with the nucleus (and genes) of a cell from the animal that scientists aim to duplicate. That cell is then stimulated and later implanted in a surrogate mother.

Cloning is costly because it is a relatively tedious process and the technology is relatively immature, comparable to the production inefficiencies to that of the early automobile industry.

Years ago, scientists were able to achieve success in only 2 or 3% of attempts, but ViaGen now boasts 10 to 15% efficiency in producing a calf. Its aim is nearer to 60%, about the same as traditional in-vitro fertilisation, Walton said.

Despite the steady improvement in the technology, consumer acceptance of cloning as a viable means to produce human food remains the top hurdle for breeders and cloning companies.

Cloning process not 100% yet
Despite cloning's gradually improving rate of success in producing healthy animals, the process still has a high rate of failure. Some animals are born with abnormalities and have to be euthanized, and some have more health problems at birth than conventionally bred animals.

Large Offspring Syndrome also occurs more often with assisted breeding technologies like cloning. The syndrome causes the foetus to grow too large, causing problems for both the clone and the surrogate.

Opponents also say the FDA's risk assessment was not thorough enough and a long-term, multi-generational study of cloning's effects on food products is needed. At the very least, the products should be labelled as derived from cloning, they say.

"The largest study looked at milk from only 15 cows. Only one study used standard methods of toxicology, and that study looked at the effects of feeding 20 rats products from clones for 14 weeks," said Jaydee Hanson, policy analyst at the Centre for Food Safety, a non-profit advocacy and research group. "We don't think that cloning is a technology that's ready yet, and we certainly don't think it's ready to be on your plate."

How to avoid cloned food
The only way to definitively avoid food from clones is to buy organic products, which by the Organic Trade Association's definition are from only traditionally bred animals, Hanson said.

The US Agriculture Department has asked the livestock industry to voluntarily keep clones out of the food supply for the moment, but the moratorium does not apply to progeny of clones. Major meat and dairy companies have said they will not accept products from clones, citing the desires of their customers.

Some have said cloned animals are far too valuable as breeding stock to be used for food, but that the progeny of clones are "undoubtedly already in the food chain." However, he said, "the proportion is infinitesimally small compared to the total meat supply, a tiny little drop in the ocean."

Still, ViaGen and the Biotechnology Industry Organisation have helped to create a supply chain management programme to track clones from birth to death. ViaGen also gives farmers the incentive to disclose when and where they cull a clone by holding a deposit until the clone's owner can verify that the animal has been euthanised, or slaughtered for meat.

In time, Walton said, consumers and food producers will become more comfortable with cloning, much like they have with genetically modified crops, but it will take time and it will take openness from cloning providers.

"Companies have a bottom line to protect, so they are cautious about new technologies and they are cautious about listening to their customers," he said. "No scientist can say definitively that nothing will be different tomorrow. But, given the body of knowledge and the amount of work that's been done, you can be extremely confident that the probability of something untoward happening is incredibly small." – (Reuters Health, November 2009)

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