KENNEDYVILLE, MARYLAND -- Sprawling over 140 acres of hilly pastures outside this Eastern Shore crossroads, the Horizon Organic dairy farm looks for all the world like a postcard. But lately, it has become a flash point in a national debate about how to raise cows to supply a burgeoning market for organic products.

At issue isn't the milk that comes from more than 500 Holsteins at the Kent County farm. It's about whether cows should be cows - or at least how much time they should get to spend outside the barn, grazing in green pastures of grass, clover or alfalfa.

Horizon, the nation's largest organic milk producer, has drawn criticism - and a formal complaint to the U.S. Department of Agriculture's organic standards board - from a Wisconsin-based industry watchdog group and a former dairy veterinarian at the Kennedyville farm.

They say Colorado-based Horizon, which keeps cows in a huge barn much of the time at the Maryland farm, is all but ignoring USDA rules requiring that organic dairy cows have "access to pasture." They acknowledge, however, that the rules do not spell out just what "access" means.

A recommendation from the organic standards board that would require that cows spend a minimum of 120 days a year grazing is under consideration by the USDA. Many advocates of organic milk say they expect little in the short term from federal agriculture officials.

"Our organization has been complaining for four years to the organic standards board about flagrant violations at these factory farms," said Ronnie Cummins, national director of the Minnesota-based Organic Consumers Association. "Horizon controls half the market."

Horizon officials bristle at the suggestion they are operating factory farms or skirting guidelines.

"We know we've been targeted by critical groups," said Molly Keveney, a Horizon spokeswoman. "It's disheartening because we have been a leader in this industry. The whole industry should be working together to improve standards."

U.S. sales of organic foods have risen 83 percent in the past four years, according to the Organic Trade Association, with sales of organic dairy products increasing by 23.6 percent. Last year, sales of organic milk and cream totaled $1.1 billion.

Confining the cows that used to graze on pastures on company farms is aimed at boosting Horizon's milk production from cows that spend much of their lives indoors, eating high-protein feed, according to Cummins.

The practice flies in the face of organic guidelines and runs counter to the company's carefully crafted bucolic image, says Dr. Robert C. Fry, who worked for eight years as the farm's veterinarian and nutritionist until he was dismissed in February.

"The issue is the company misrepresenting itself to the consumer with all the marketing with happy cows outside grazing," Fry said. "They'll have some token cows outdoors whenever there's a tour. I live about three miles away and go past there maybe two or three times a day.

"It would be apparent to someone who is knowledgeable about pasture management that the cattle haven't had access to pasture," Fry said. "I've been in the dairy business all my life, and I know when cows are on grass and when they're not."

Officials at Horizon insist that the allegations that cows are not allowed outdoors are untrue. Grazing, they say, is an essential element on any dairy farm, even in large operations such as Kennedyville's or at a Horizon farm in Idaho, with 4,000 cows.

"This is just absolutely false," said Greg Heidemann, an Idaho dairyman who was hired a year ago to run the farm in Kent County. "It's the nature of a cow to graze. I have pasture reports on every cow. I haven't done anything to be ashamed of and neither has the staff."

According to Heidemann, who keeps pasture records on each cow at the farm in a thick spiral notebook, the company is exceeding the standards proposed but not adopted by the USDA. On average, he said last week, the cows in Kennedyville had been out to pasture 141 days this growing season.

As for the lack of grazing cows reported by Fry, Heidemann says the animals are kept in the barn during hot summer days, cooled by large electric fans and a sprinkler system. "It would be brutal for them to be out in the kind of heat we've had," Heidemann said. "With the weather like this, we're letting them out at night."

At Horizon's dairy farms, or any certified organic operation, cows eat food that is grown without chemical pesticides and herbicides. Farmers who supply the grain must show that their fields have been chemical-free for at least three years. Organic cows are raised without antibiotics or growth hormones.

Horizon officials gave a reporter a tour of the barn here - a building the length of three football fields with a roof and open sides - but would not allow a photographer on the property, saying it is against company policy. The roughly 500 cows are scrutinized by a video monitoring system two or three times a day as they are milked. The company acknowledges that they spend a good portion of their lives eating high-protein feed in concrete troughs. The animals are free to move about, eating when they please or sleeping on sawdust beds.

Mark Kastel, one of the founders of the Cornucopia Institute, an industry watchdog group, says the Maryland farm is not large enough to accommodate 500 or more cows. "At the very least, they are breaking the spirit of the law," Kastel said. "On a real organic farm, there's a connection with cows, land and people. There's an altruistic reason consumers pay so much more for organic milk. They think they're doing something that's healthier, good for the environment and protecting family farmers."

Kastel and other Horizon critics characterize the Kennedyville farm and the company's operation in Idaho as factory farms, a system they say runs contrary to organic ideals.

But the company says the large-scale dairies account for only 20 percent of production. Eighty percent, Keveney says, comes from small family farms.

"Overall, we average 200 cows per farm, and the average east of the Mississippi is about 75 per farm," Keveney said. "We have 342 family farms in our network and another 240 making the transition to organic. The truth is, we've scoured the nation for farmer-partners to help meet increasing demand."

John Hall, Kent County's longtime agricultural extension agent, says the dispute is unlikely to be resolved until grazing requirements for organic farms are spelled out. "Right now, it's very fuzzy, a gray area," Hall said.