NARA, Japan (CNN) -- Japanese researchers have cloned eight genetically identical calves in what is a first step towards boosting the country's beef and dairy industries.

In a study to be published this week in the journal Science, researchers from three Japanese institutions report that the calves were cloned with techniques similar to those used to clone the famed Scottish sheep known as Dolly.

A team led by Yoko Kato of Kinki University in Nara set out to produce 10 cloned calves from one adult cow using the new technique.

Cloning cows in this manner, the scientists said, gives an important economic benefit because it could, in effect, duplicate cows that are "proven to be ideal milk and meat producers."

In the cloning of an adult animal, scientists must choose which type of cell from the animal to use to harvest a nucleus, the part of the cell which contains genetic material.

The Japanese team chose to harvest nuclei from two types of cells: six nuclei were from cumulus cells (which surround eggs inside ovaries) and four nuclei were from oviductal cells (which line a cow's oviducts).

The nuclei were transferred into ten donor eggs taken from one cow. The eggs were grown in the laboratory to the blastocyst stage of development, which is an early embryonic stage. The embryos were then implanted into the ten surrogate cows.

Each of the surviving calves is a genetic duplicate of the cow from which the cells were removed, the researchers said.

Japanese researchers reported last month that they had cloned at least 15 calves using the Dolly technique. Japan imports much of its beef and agricultural researchers have been aggressively studying cloning techniques as a way of improving the meat and milk production.

Dolly was the first mammal in history to be cloned from an adult cell. Researchers announced last year that the Finn Dorset sheep was cloned from using the nucleus taken from a cell that had been removed from the udder of an adult sheep.

American researchers have since cloned calves using cells taken from unborn cows. Laboratory mice also have been cloned using the Dolly technique.

In the new Japanese work, the researchers used two different types of cells removed from the reproductive tract of a single Japanese beef cow. Both types of cells carried the same genetic pattern as the donor adult cow, and all of the cloned calves retained this same pattern, proving that they were true clones, the researchers said.

However, the Japanese researchers said they have achieved a higher degree of efficiency than earlier Scottish and American researchers. They said that 23 percent of one type of cell, the oviductal, developed into advanced embryos, while 49 percent of another type of cell, the cumulus, were successful.

Dolly's creators had hundreds of failures and some American researchers reported a success rate of only about 12 percent.

The Associated Press contributed to this report.