The U.S. Department of Agriculture has imposed strict new standards for what kind of milk qualifies as organic: Cows must get plenty of fresh grass and spend at least four months a year grazing in pastures.
The rules, which will go into effect June 17, are aimed at standardizing industry practices and easing consumer concerns about how the milk they buy is created.
Current rules require milk marketed as organic to come from cows whose feed was grown without chemical fertilizers, pesticides or genetically modified seeds. Herds can't be treated with hormones or antibiotics.
The new rules seek to close loopholes that had allowed some of the country's largest feedlots to sell their milk as organic, even though their herds rarely grazed in fields. Bovines are natural grazers that have been known to contract digestive ailments from grain. Farmers will have to ensure that at least 30% of their cows' diet comes from pasture grass during the mandatory grazing season.
Farmers in more temperate regions -- such as California and the Southeast -- will be expected to let them eat au natural far longer than the minimum 120 days.
"You can meet this threshold whether you're in Vermont or Arizona," USDA Deputy Secretary Kathleen Merrigan said Friday.
California is the nation's largest producer of organic milk, according to the USDA. Organic dairy products were a $3.6-billion industry in the U.S. in 2008 and made up about 5% of all dairy products sold, according to research compiled by the Organic Trade Assn.
Organic milk is pricey. A gallon of Safeway's Lucerne whole milk sells online for $2.99, while a gallon of Horizon Organic whole milk sells for $5.99.
The regulations also apply to cattle being raised and sold as organic beef, as well as other ruminant livestock such as goats, sheep and buffalo. The agency is still weighing one exemption for non-dairy cattlemen: Although animals being raised for slaughter must have access to pasture, ranchers can forgo the dietary requirement during the animals' last four months of life.
The standards help settle a long-running debate between organic activists and farmers and livestock ranchers over how much time the animals need to spend roaming across the plains to earn the organic certification.
Merrigan said that many organic dairies already met the grazing requirements but acknowledged that some farmers would have to change their practices to live up to the new standards.
The change worried members of Western United Dairymen, a group that represents more than half the dairy farmers in California.
"Those up in the north Bay Area -- Humboldt County, Sonoma County -- they get up to 40 inches of rain a year, which means animals covered in mud in the pastures, which can lead to illness in the animals," Chief Executive Michael Marsh said.
Organic activists, however, were cautiously hopeful.
"The success of this rule will depend on the USDA enforcing the bigger picture, of cows being on pastures," said Alexis Baden-Mayer, political director of the policy group Organic Consumers Assn.