Over-reliance on just a few breeds of imported farm animals is putting others in poor countries at risk of extinction, researchers warned.

Dependence on a handful of breeds like high milk-yielding [Holstein-Friesian](http://www.answers.com/topic/holstein-cattle “Answers.com”) cows, egg-laying [White Leghorn](http://www.answers.com/topic/leghorn-chicken “Answers.com”) chickens and fast-growing [Large White](http://www.ansi.okstate.edu/breeds/swine/largewhite/index.htm “Oklahoma State University”) pigs is causing the loss of one breed on average every month, U.N. Food and Agriculture Organisation (FAO) scientists say.

It’s estimated that 90 percent of cattle in industrialized countries come from only six very tightly defined breeds.

[Read](http://www.enn.com/animals/article/22608 “Read the Story”) (Environmental News Network)