A pilot study found that both met industry standards, marking what might be a first step towards the introduction of meat and dairy products from clones.
Scientists in the United States and Japan cloned a bull and a cow using the "Dolly" technique of transferring genetic material from an adult cell to an egg.
Meat and milk from the clones was compared with that from normal animals of similar age and breed. Two beef and four dairy clones were used in the study.
Analysis of protein, fat and other variables revealed no significant differences in milk from the cloned dairy cows.
More than 100 meat quality criteria were also examined. Of these, 90% also showed no significant variation between normal and cloned beef. The findings, from a team led by Jerry Yang, from the University of Connecticut, appear in the journal Proceedings of the National Academy of Sciences.