INTERLAKEN, Switzerland - The rate at which livestock breeds are disappearing is "alarming," a senior official at the U.N. Food and Agriculture Organization said Tuesday, warning that precious genes could be lost forever.

One rare breed is becoming extinct every month because farmers _ particularly in Asia and Africa _ are importing high-yield animals such as Holstein-Friesian cows and White Leghorn chickens, the agency's Assistant Director-General Alexander Mueller told an intergovernmental livestock conference.

As a result, unique genetic material that could protect farm animals from future threats posed by disease and climate change might disappear, he said. "In this situation, the world cannot simply take a business-as-usual, wait-and-see attitude."

With at least one in five breeds of cattle, goats, pigs, horses and poultry at risk, the U.N. body is urging delegates at the meeting in Interlaken to adopt a 10-year rescue plan.

It would involve stepping up monitoring efforts in the developing world, where most of the endangered breeds can be found, and setting up gene banks to preserve vital traits, such as resistance to disease and extreme climate conditions, which have developed over centuries.

Carlos Sere, director-general of the Nairobi, Kenya-based International Livestock Research Institute, said freezing semen, eggs and embryos in liquid nitrogen tanks is an uncomplicated and cheap way of preserving useful genes so they can be reinserted into animal populations when needed.

"In the long run, the benefits of having a genetic insurance are probably going to help developed countries as much as developing countries," Sere told The Associated Press before of the meeting.

Among the breeds the International Livestock Research Institute says are most at risk are the Ankole cattle, whose drought resistance and rich milk made them prized animals in East and Central Africa until the arrival of European dairy cows.

Similarly, the Red Maasai sheep of East Africa, which have developed genetic resistance to a common parasite, have almost disappeared since the introduction of Dorper sheep from South Africa 15 years ago, the research institute says.

Rich countries have already recognized the importance of maintaining a diverse gene pool, the U.N. report says.

Farmers in the Swiss canton (state) of Valais are cultivating a breed of cattle known as Evolene Cow, famed for its robustness and fierce nature.

Tamworth pigs, known for their lean meat, have also won favor with breeders in the United States and Britain who want to preserve them for crossbreeding with more common porcine varieties.

An independent expert not attending the conference said that preserving genetic diversity was a prudent step, regardless of whether new diseases or climate change actually affect farming.

"It's so difficult to second guess what the future may hold. Livestock types that may have little value now may have great value in the future for any number of reasons," said Glenn Selk, a professor of animal science at Oklahoma State University.