"No differences exceeding the normal variability have been observed in the composition and nutritional value of meat and milk between healthy clones or the progeny of clones and their conventional counterpart," the report said. It did, though, highlight animal welfare concerns.
The European Commission said this week that it would consult the public before making a ruling in May.
The US food industry has been holding off selling food products from clones since 2001. Bruce Knight, the US Department of Agriculture under-secretary for marketing and regulatory programs, expected a voluntary moratorium on products from the 600 clones at present on farms to continue for several months.
Even after the ban is lifted in the US, it is unlikely pork chops and steaks from cloned livestock will reach shops because the technology is too expensive to use clones for anything but breeding.
The moratorium does not apply to the offspring of clones, but given that there are 200 million meat- and milk-producing farm animals in America, it will probably take several years before there are enough progeny to have a significant impact on the food supply.
Also, many in the food industry want to wait before introducing food derived from clones. Food makers and sellers fear a trade backlash. They also worry the possibility will scare away customers in the same way that use of hormones to increase milk production spurred many people to turn to organic products.
One organic food advocate, Rachel Griffith, who lives in Milan, Illinois, said she would now shun meat from her favourite grocer and try to buy directly from local farmers, so she knows it comes entirely from conventionally bred animals. She also said she would be careful about which brand of organic milk she bought to avoid any from clones or their offspring.
"I have two children – two young, growing children – and I want them to get healthier, not sicker, after eating their meals," said Griffith, a 41-year-old health magazine saleswoman.
Joseph Mendelson, legal director for the Centre for Food Safety, urged the US Congress to pass legislation requiring the labelling of food from clones and further study of its long-term safety.
Critics of the use of cloning in agriculture point out that the method used to create identical animals – essentially the same used as to produce Dolly the sheep – is inefficient, with a significant proportion of embryos not developing to maturity. Even some apparently successful cloned embryos are prone to severe developmental problems after birth. Scientists say the loss rates are coming down as the technology improves.
Joyce D’Silva, of Compassion in World Farming, based in Britain, said: "It’s a technology that has arisen out of a huge burden of animal suffering and that is still going on." She said that even if the embryo loss rates were brought down to acceptable levels, the technology would be detrimental to animal welfare.
Scientists counter that cloning can be used to enhance animal welfare, for example by spreading useful genetic mutations that make animals resistant to diseases such as scrapie.
D’Silva is also concerned that cloned US meat could enter the European food chain even if consumers there did not want it.
Supporters of cloning hope the US Food and Drug Administration’s respected imprimatur, along with a growing appreciation that the technology does not involve genetic modification, will persuade most consumers to view cloning as simply the latest farm technology.
Cloning would be a boon to dairy farmers looking for the best milk producers and slaughterhouses seeking cows, goats and pigs yielding the highest-quality meat. Until now, industry has used other reproductive technologies, such as artificial insemination or in vitro fertilisation, to obtain prized traits. Through cloning, they would get identical copies of the most valuable animals.
Scientists make a clone by taking the original’s genetic material and placing it into the egg cell of another animal whose own DNA has been removed. The embryo that develops is transferred to a surrogate mother, who gives birth to the matching twin.
Carol Keefer, an animal sciences expert at the University of Maryland who helped the Food and Drug Administration make its determination, said: "The issue of food safety is being brought up by some groups because they object to the process, but that’s a separate issue. They should focus on those concerns."
Biotechnology companies have been waging a public relations campaign to change public perceptions of "Frankenfoods".
Most recently, the two leading cloning companies, ViaGen and Trans Ova Genetics, sought to ease minds by developing a system for tracking clones as they make their way from farms to processing plants to shops. Groceries could tell customers whether a product came from a clone, but the system does not account for food made from the offspring of clones, the probable source.
The Baltimore Sun, Agence France-Presse, Guardian News & Media