WASHINGTON -- It's not quite a case of making a silk purse out of a sow's ear, but U.S. corporate researchers said on Monday they had cloned piglets from cells taken from the ears of two prize boars.

It is the first time a pig has been cloned from an adult cell, as opposed to cells taken from a pig fetus, said the team at Infigen Inc., based in Deforest, Wisconsin.

"Clones of 'The Man' were born January 14 while clones of the deceased '401K' were farrowed December 25, January 6 and January 14," Infigen said in a statement.

"All of the clones are healthy and vigorous. Both boars are owned by Prairie State Semen, Inc. of Champaign, Illinois."

One of the ideas behind cloning farm animals is to be able to duplicate prize animals precisely. Semen from elite males can sell for $100 or more a shot, but the uncertainties of natural mating make it a risky investment.

It was lucky one of the boars, "401K," was cloned when he was, Infigen chief financial officer Eric Postel said. The animal died the day after the piece of tissue was taken from his ear to make the clone.

"He's gone, but now he's back," Reuters quoted Postel as saying in a telephone interview.

The pigs were valuable to start with, and Postel said Infigen sold the clones to prairie state for "in the high five figures."

"'The Man' was the champion Yorkshire boar at the 2000 Indiana State Fair," Infigen said. "Prairie State Semen purchased him for $77,000 -- a breed record at that time. '401K' was purchased by the company in 1997 for a record-setting $43,000."

Infigen's main research aim is to make animals that could be used for animal-to-human organ transplants, but Postel said he thought the sideline of cloning prize farm animals would be profitable.

"We wouldn't do it if we couldn't make some money," he said.

Postel was not sure how many of the clones survived.

Cloning is still a very tenuous business and many, if not most, animals die early in pregnancy or right around the time of birth. "We lost a couple," he said.

On Sunday, Japanese researchers reported that most of the mice they had cloned had died young, of apparent lung and liver damage. But the cloning method used to make large farm animals is different from the method the Japanese researchers used, and companies such as Infigen say they produce healthy adults animals.

Infigen has cloned beef and dairy cattle, domestic pigs and sheep.