Milk and meat from cloned cattle appear safe for human consumption, a pilot study has found.
No clone products have entered the food chain yet
Scientists in the US and Japan found that meat and dairy products from a bull and cow cloned using the "Dolly" technique met industry standards.
The team says its results suggest cloning techniques could be used to boost food production, particularly in developing countries.
The study appears in the Proceedings of the National Academy of Sciences.
Two beef and four dairy clones were used in the research, all derived from a single Holstein dairy cow and a single Japanese black bull.
The scientists, led by Jerry Yang from the University of Connecticut, compared the produce with that from normal animals of similar age and breed.
The scientists found no significant differences in their comparisons of the milk and meat.
They did find higher levels of fat and fatty acids in the cloned cow meat, but said that these still fell within beef industry standards.
Higher levels of fat can also be seen as a desirable quality in the Japanese black breed of bull that was used for cloning.
The meat was also analysed against more than 100 meat quality criteria, while the milk was analysed for protein, fat and other variables.
The researchers said the milk results indicated that the genes of the cloned animals were functioning normally.
"The production of each milk protein constituent involves the elaborate regulatory function of many proteins and enzymes, and any abnormal gene expression would likely be reflected by imbalances in the constituents of milk," they wrote.
The scientists concluded that the study showed the produce to be within the range approved for human consumption. But they stressed the research was at an early stage.
They said the findings provided "guidelines" for further research with larger numbers of clones from different genetic backgrounds.
Cloning offers the possibility of raising yields by copying especially productive animals or ones that are resistant to disease.
"The milking production levels in the US are three to four times higher than levels in China; maybe even five times or more compared to cows in India and some other countries," Professor Yang told BBC News.
"Therefore cloning could offer technology for duplicating superior farm animals. However, all the products from these cloned animals must be safe for human consumption. ...and it is a major issue for scientists to provide a scientific basis for the data and information to address this question."
But the cloning technique has raised welfare concerns, as most copied animals do not make it to term before being born, and many of those that do are born deformed or prone to illness.
Opponents of the use of cloning in livestock husbandry are also worried that seemingly healthy clones may still have subtle defects that could make their food products unsafe to eat.
"We don't know what this technology will result in in the future; we know so far that it is unsustainable," Compassion in World Farming director, Joyce D'Silva, told BBC News.
"Huge numbers of animals die. They are born with deformed lungs, hearts and kidneys which don't function. They die slow and lingering deaths. Is this the technology that we need or want? I don't think so."
Animal food products from clones have yet to enter the food chain in any country.
Two studies comparing milk and meat respectively from cloned cattle with that from normal animals were published in the journal Cloning & Stem Cells last year. They came to similar conclusions.