Before the end of 2007, Chipotle Mexican Grill (NYSE: CMG – News and CMG.B – News) will no longer serve any cheese made with milk from cows treated with the synthetic hormone rBGH (recombinant bovine growth hormone). That will make Chipotle the first national restaurant chain to eliminate rBGH entirely from items on its menu.

Chipotle began serving 100 percent rBGH-free sour cream last year, and has begun shifting to rBGH-free cheese over the last several months, a move it will complete by year-end, making 100 percent of its cheese rBGH-free. It also serves rBGH-free, organic milk at some of its locations.

rBGH, also called recombinant bovine somatotropin or rBST, is a synthetic hormone that stimulates milk production in dairy cattle. Use of rBGH has been banned in a number of countries, including 25 European nations, Canada, Australia, New Zealand, and Japan. Since its approval by the U.S. Food and Drug Administration in 1993, the use of the hormone in this country has been controversial for many reasons, including potential health concerns for humans and the animals treated with the hormone.

”We want to change the way the world thinks about and eats fast food,” says Chipotle Founder, Chairman and CEO, Steve Ells. ”Serving our customers cheese and sour cream without rBGH is the responsible thing to do. It’s better for our customers, better for the animals, and better for the food system.”

Today’s announcement represents the latest development in Chipotle’s Food With Integrity mission – a commitment to making socially responsible, gourmet food available and affordable so everyone can eat better. To that end, Chipotle now serves more naturally raised meat than any restaurant in the world–meat raised humanely without antibiotics or added growth hormones, and fed a pure vegetarian diet. Beyond naturally raised meat and rBGH-free dairy, 25 percent of the black and pinto beans Chipotle serves are organically grown.

”We care about the quality of the ingredients we are serving,” says Ells. “Everyone should have access to great-quality, great-tasting food. So, we look for ingredients that are grown and raised with care and respect.”

According to the results of a recent survey conducted by Opinion Research Corporation, 81 percent of respondents would prefer to buy dairy products derived from cows that do not receive synthetic hormones, assuming little or no pricing difference. Other findings from the Opinion Research Corporation survey include:

* Of those who said they would not prefer to buy rBGH-free dairy products, 64 percent said that they would buy rBGH-free dairy products if the synthetic hormone was linked to health issues with humans, and 42 percent said they would if the use of rBGH was linked to health issues with dairy cattle.

* Fifty-eight percent of respondents were aware that many dairy cows in this country are treated with rBGH.

* Nearly half of those who had no preference said they would prefer to buy rBGH-free dairy products if they knew the hormone was banned in a number of other countries.

“Chipotle has been making positive changes to the food supply system for a number of years, and we’re extremely pleased that they’ve chosen to make being rBGH-free part of that commitment,” says Rick North, director of the Oregon Physicians for Social Responsibility’s Campaign for Safe Food, a non-profit group that’s been collaborating on a nationwide education campaign opposing rBGH.

“As consumers become more aware of the issues associated with rBGH use and the alternatives companies like Chipotle are providing, they are clearly stating their preference for rBGH-free dairy products.”