PORTLAND – For Monsanto, Oakhurst Dairy presented a problem. Not only was Oakhurst refusing to buy milk from farmers who used a Monsanto product called Posilac, it was promoting its milk on the fact.

Oakhurst labels and markets its milk as coming from farmers who vow not to use artificial growth hormones to increase cows’ milk production. Posilac is the only such hormone approved by the Food and Drug Administration.

Monsanto Co. is now suing Oakhurst, accusing it of misleading labeling and advertising that Monsanto says disparages its product.

Oakhurst, however, is hardly alone. Dozens of dairies and food retailers nationwide promote their milk, cheese, butter, yogurt and other dairy products as coming from milk from cows not given growth hormones.

Critics say this type of marketing is deceptive – if not downright false. Supporters ask: What’s wrong with telling consumers what’s not in their milk?

Stanley Bennett II, president of Oakhurst, said he’s in the business of selling milk, “not marketing Monsanto’s drugs,” and has no intention of giving in to Monsanto’s demands.

“We know we’re doing the right thing; we have universal support from our customers around Maine and New England,” Bennett said while giving a tour of the dairy, which has been in the family since his grandfather bought it in 1921. “But I know it’ll be a tremendous amount of money, and being an old Yankee I hate the idea of throwing money at lawyers.”

The dispute centers on rBST, or recombinant bovine somatotropin, an artificially produced hormone that is injected into cows to increase their milk production. Posilac is the brand name of Monsanto’s version of rBST.

The FDA says milk produced by rBST-injected cows is indistinguishable from milk from cows not treated with rBST, and poses no health risks to humans or cows.

But opponents of rBST say there is no consensus in the international scientific community over its safety, and point out that rBST is banned in Canada and Europe. They also say rBST is harmful to cows, and that the use of rBST poses a threat to family farms.

Nearly a decade after rBST was approved by the FDA, there now appears to be a growing number of companies large and small marketing their dairy products as coming from cows not treated with rBST.

They include dairies such as Hood, Garelick Farms, Land O’ Lakes, Kemp’s, Humboldt Creamery and Berkeley Farms, and retailers such as Trader Joe’s, Whole Foods Market and Wild Oats Markets.

Alex Avery of the nonprofit Hudson Institute’s Center for Global Food Issues said companies that make claims about milk from cows not treated with rBST should include a qualifying statement recommended, but not required, by FDA labeling guidelines.

That statement says that there is no significant difference between milk from rBST-treated and non-rBST-treated cows.

Oakhurst and several other companies don’t include the FDA’s wording on their products. Others put the statement in small letters on their products but don’t include it on in-store displays, in newspaper ads, on Web sites and through other marketing venues.

A coalition of consumer groups, which includes the Center for Global Food Issues, has written the FDA and officials in Massachusetts, Washington, California, New Jersey and New York complaining about what they call misleading marketing and labeling claims.

The letters say commonly used phrases that are false include “rBST-free” (all milk is rBST-free) and “hormone-free” (all milk has hormones). The letters further allege that claims that farmers don’t use rBST are misleading because they imply that milk from rBST-treated cows is somehow tainted.

“This not a corporate agenda,” Avery said. “There are serious ethics issues behind these labels.”

Bob Wellington, an economist with Agri-Mark Co. dairy cooperative in Lawrence, Mass., said Monsanto officials once asked him: “How do we deal with this Oakhurst problem?” Even though Wellington was surprised when Monsanto sued, he agrees that Oakhurst’s marketing is deceptive.

“I think Stan Bennett uses it as a scare tactic to help sell milk,” Wellington said.

But others say Oakhurst is doing nothing wrong. Consumers, they say, want to know if their milk is produced with rBST because of concerns about human health, animal health and the future of small dairy farms.

Ronnie Cummins, national director of the Organic Consumers Association in Little Marais, Minn., said he thinks Monsanto is suing Oakhurst because it lost $1.7 billion last year and is “desperate.”

“They’re starting to bully dairies again,” he said. “They know fully well it’s legal to do what Oakhurst is saying.”

Michael Hansen, a senior researcher at Consumers Union in Yonkers, N.Y., said telling consumers that milk doesn’t have artificial growth hormones is like telling them a food doesn’t contain artificial flavors or colors. Nobody’s complaining about that, he said.

“Are those misleading as well because they imply that artificial flavors or artificial colors are bad for you?” he asked.

St. Louis-based Monsanto chose to sue Oakhurst because the dairy has become more aggressive in its marketing on the hormone issue in recent months, said spokesman Bryan Hurley. Monsanto is not specifying financial damages, nor would Hurley speculate on future lawsuits against other companies.

But many think the lawsuit will help Oakhurst more than Monsanto. After all, this is a David vs. Goliath type of case, and people love an underdog.

Oakhurst has annual sales of $85 million, 240 employees and a mascot named Oakie the Oakhurst Acorn. It pitches itself as a community-minded company that gives 10 percent of its profits toward children’s and environmental causes.

Monsanto manufactures chemicals, seeds and other agricultural products and had 2002 revenues of $4.7 billion. It has more than 13,000 employees and a presence in more than 50 countries.

“I told Monsanto I don’t see what they’re going to gain from this,” said Wellington, of AgriMark, “other than to give Stan Bennett a tremendous amount of publicity he wants.”