Study finds hormone may make dairy farming greener

By Julie Steenhuysen

CHICAGO (Reuters) - Using bovine growth hormones to boost milk production could help the dairy industry significantly reduce its impact on the environment, U.S. researchers said on Monday.

They said supplementing 1 million cows with the growth hormone recombinant bovine somatotropin or rbST would have the same effect as removing about 400,000 cars from the road or planting 300 million trees.

"That's a pretty substantial impact," said Dale Bauman of Cornell University, whose research appears in the journal Proceedings of the National Academy of Sciences.

While it has been approved for sale by the U.S. Food and Drug Administration since 1993, the hormone has been banned in Japan, Australia, Canada and parts of Europe. Opponents say it can have harmful effects on both the cows and humans who drink their milk.

Many U.S. grocery chains in the United States have switched to milk suppliers that do not use the synthetic hormone, and Wal-Mart Stores Inc said in March its private label brand of milk would be sourced from suppliers that do not use growth hormones.

Cornell University paid for the study, done with the help of Roger Cady of Monsanto Co, maker of the bovine growth hormone Posilac.

The study focused on environmental, not safety, issues.

FEWER COWS, LESS FEED