For demanding consumers, some dairy producers are demanding less milk from their cows -- and charging more for it.
The dairy companies are bowing to the natural-foods trend by shunning milk from cows treated with genetically engineered growth hormone.
By labeling milk free of the artificial hormone, the dairy industry can ride the popularity of natural foods, without the greater expense and special feeds required to produce milk that can be fully certified as "organic."
As a result hormone-free milk can be priced higher than conventionally labeled milk, but less than organic.
At a Safeway near central Seattle, for example, a half gallon of conventional Lucerne-brand whole milk was recently selling for US$1.69, while the Horizon organic brand was priced at US$3.69.
Priced neatly in between, at US$2.79, was the Darigold milk labeled as "coming from cows not treated with the growth hormone rBST."
An asterisk after the hormone name referred to tiny letters near the bottom of the carton indicating that the Food and Drug Administration says there is no difference between milk from treated and untreated cows.
Some milk producers have long avoided the hormone rBST, which is made by Monsanto and was approved by the FDA in 1993. But it has been in wide enough use since then, as a way to increase a cow's milk supply by a gallon or more a day, that many of the nation's dairy products probably contain milk from cows injected with the hormone.
Many pure-food advocates oppose the hormone's use on health grounds, saying it can require cows to be treated with extra antibiotics and can result in milk with higher amounts of a separate hormone linked to cancer in some studies. But only recently do more consumers appear to be paying heed to those concerns, as part of the growing interest in whole and natural foods.
Experts say that avoiding the hormone is the main reason people buy organic milk, whose sales have been growing rapidly the last few years. But organic sales still account for only about 3 percent of the total milk market, so marketers see an opportunity to tap the demand for organic milk by simply eliminating the hormone.
"It seems to be an explosion in the industry," said Kurt Williams, general manager of Lanco-Pennland Milk Producers, a cooperative in the mid-Atlantic region, most of whose members do not use the hormone.
"All of a sudden we have national processors like Dean Foods taking entire plants hormone-free," he said.
Dean Foods, the US' largest milk producer, stopped accepting milk from hormone-treated cows in June at a large bottling plant it owns in Florence, New Jersey, that sells milk under the Tuscan name. That means most of the Tuscan milk sold in the New York metropolitan area is now free of the artificial hormone.
Dean Foods is now beginning a similar shift at its New England plants, which market the Garelick Farms brand, and is considering a similar move in Texas. Still, Dean Foods says only 10 of its 100 milk processing plants around the country offer milk from untreated cows.
"Are we doing a wholesale shift -- no," said Marguerite Copel, a spokeswoman for Dean. "Are we seeing movement? Yes."
Darigold, which is owned by the Northwest Dairy Association, a large cooperative, recently began selling milk only from cows not treated with growth hormone. Several other dairy companies in the Northwest have recently done likewise.