One consumer lobby, the Center for Food Safety, has filed a legal petition asking the US Food and Drug Administration (FDA) to launch a moratorium on food from cloned animals.
Debate was re-ignited last week after the FDA said a draft of plans to regulate food from cloned animals could get government backing by the end of the year.
If approved, the move holds both opportunities and risks for dairy firms, which may use cloning to improve breeding but could also face a storm similar to that surrounding genetically modified foods.
The FDA said studies showed meat and milk from cloned cows were as safe as produce from conventional herds, a view it has voiced several times in the last four years.
One main study published last year said it found no difference in milk quality, including protein, fat, antibody and lactose content, from cloned cows.
The study, conducted jointly by the University of Connecticut and the Kagoshima Prefectural Cattle Breeding Development Institute (CBDI) in Japan, has been used to support the FDA's argument.
Opposition to apparent FDA plans to approve food from clones came immediately. "The FDA has never made its full risk assessment or scientific studies available to the public nor provided an opportunity to comment," said Carol Foreman, of the Consumer Federation of America.
Both she and the Center for Food Safety questioned whether consumers would buy products from cloned animals.
Almost two thirds of Americans said they were uncomfortable or strongly uncomfortable with animal cloning, in an independent survey last year. And a similar number said they would not buy food from cloned animals even if the FDA said it was safe, a survey by the Pew Initiative on Food and Biotechnology found.
Opposition to food from cloned animals could be reinforced by concerns for animal welfare, amid reports that claim animal cloning research has led to premature deaths and abnormalities.
These issues, together with moral arguments against cloning, may be enough to make dairy firms nervous about using the technology.
Supporters of animal cloning said dairy and meat producers could improve their products and their businesses by selecting the best performers in terms of quality and yield, however.