The cows that produce the nation's organic milk spend their days ruminating happily on an idyllic green pasture, usually beside an iconic red barn. That, at least, is what the ubiquitous marketing would tell you.

Now an agricultural watchdog group based in Wisconsin has taken the trouble to obtain aerial photos of 14 large-scale organic farms - five dairies and nine chicken operations that supply well-known store brands such as Walmart, Target and Costco, according to the group. Not surprisingly, the reality is less picturesque and more industrial than that advertising image.

More importantly, according to the group, the aerials taken in May and June of this year show very few animals outside, even though organic rules require that animals be allowed daily free access to the outdoors. Cows and chickens that are allowed outside to forage yield more nutritious milk and eggs, according to some studies.

The watchdog group, the Cornucopia Institute, says that the evidence it has collected indicates that the USDA program has too freely certified farms as “organic.” It is filing complaints with the USDA against the 14 operations.

“If you showed these pictures to people buying milk and eggs at Whole Foods, they’d be appalled,” said Mark Kastel, co-founder of the group. "For the past 10 years, we have observed systemic violations of the law at numerous industrial-scale livestock facilities representing themselves as 'organic.'"

Here, for example, is one of the Cornucopia aerial photos of a Texas dairy, certified organic by the USDA. It was taken on a mild May day this year. Only a small portion of the cows are out, and none are grazing in a pasture, as Cornucopia notes.

The complaints from Cornucopia revive a longstanding argument within the industry over the access that "organic" animals should have to the outdoors. The complaints also stir an ongoing controversy over whether industrial-scale livestock facilities can be faithful to the ideals of the organic movement.

Current organic rules, in addition to prohibiting the use of antibiotics and hormones, call for animals to live in conditions that accommodate their "health and natural behavior." Toward that end, they are supposed to have year-round access to the "outdoors," a seemingly straightforward term that has become subject to intricate interpretations.

For dairy cows, the rules mean that the animals are supposed to be allowed to pasture during the grazing season, the duration of which can vary by location, but must be no shorter than 120 days.

For chickens, however, the rules are more ambiguous. Some farms merely give birds access to enclosed porches and say that this satisfies the "outdoors" requirement, while critics say that is a perverse reading.

"Who thinks a porch with a concrete floor and a roof is the outdoors?" Kastel said. "They are making things up as they go along and the USDA has gone along with it."

Kastel said the vast majority of organic farmers follow the spirit and letter of the regulations; his group offers consumers a scorecard rating the dairy and egg brands according to their compliance with the regulations.

While the growing season is long, the photos offer evidence only about one instant in time, however, and representatives of some of the farms named in the Cornucopia complaints said the pictures do not fully represent their operations. Regardless of the images, they said, they are in full compliance with the rules for the USDA designation of "organic."

This photo, for example, is one of the Texas facilities run by Aurora Organic Dairy, a leading producer of retail store brands. It has supplied Wal-Mart, Target, Costco and other supermarkets, according to Cornucopia. Kastel noted the absence of cows on green fields, but an Aurora spokesperson said their records show that the cows went out to pasture that day.

"A single photo doesn’t really tell us anything about a farm and its practices," said Sonja Tuitele, a spokesperson for Aurora Organic Dairy, "Our records do indicate that all of our lactating cows at the Coldwater facility were grazing on pastures on May 17th. Since we don’t know what time of day this photo was taken, we can only assume this photo was taken outside of their daily grazing hours."

The shadows in the photo suggest it is about mid-day.

Tuitele also noted the photo does not include all of the surrounding fields. However, other Cornucopia photos taken of the surrounding land, some of it grassy, shows no other cows out.

Another of the targets of the Cornucopia complaints is the Idalou Egg Farm in Idalou, Tex., shown here.

A representative of the operation said that the birds may not have appeared outside because it was near mid-day and the birds may have been seeking shade. Also, he said, birds standing in the shade may not appear in the photo.

“Based on what I see in the picture, it's high noon," said David Will, general manager of an associated company, Chino Valley Ranchers. "You will find that birds avoid being outside on bright sunny days. They are a prey creature. They are not predators.”

Kastel said a high-resolution copy of the photo shows no birds out at the facility - even in the shade.

"When people buy organic milk and eggs, they are buying the story behind the label," Kastel said. "We have a wonderful, romantic story. When they see the reality, they really feel betrayed."

UPDATE: The Organic Trade Association, an organic industry group, sent a statement after this story published, saying aerial photography cannot verify compliance with organic rules.

“We continue to have confidence in the oversight of organic operations and in the checks and balances built into the organic certification system which includes regular inspections of operations, regular accreditation audits of certifiers, and complaint investigation procedures,” it said in statement.

UPDATE 2: Chino Valley Ranchers sent us this photo from this morning showing their chickens outside.