Some call it BST. Some call it BGH. Others call it curse or salvation. Whatever the term, it is a potential billion-dollar offspring of the biotechnology revolution that has set off an uproar in America's dairy industry.

The advent of bovine somatotropin (BST), or bovine growth hormone (BGH), means that the nation's already overproductive cows soon will be able to churn out from 10 to 40 percent more milk at little extra cost to the farmer.

Although BST is not expected to get federal approval for at least two more years, its potential impact already is reverberating in the nation's dairy barns and has ignited fierce debate in Congress and elsewhere over biotechnology and farm policy.

In less parlous times, the development of a technology that promised to make farmers dramatically more productive might be hailed. But BST's timing could not be worse. It comes as the government is killing 1 million dairy cows in an effort to reduce milk surpluses that have cost more than $1 billion annually in recent years.

Both sides in the debate over BST agree on several points. If adopted widely by dairymen, as expected, milk production could rapidly rise again and force up government surplus costs or drive less-efficient farmers out of business -- or both. The prospect drives federal dairy policy architects, such as Rep. Tony Coelho (D-Calif.), up the proverbial wall.

"Nobody has demanded that BST be developed. Consumer demand is not there; dairy industry demand is not there," said Coelho, chairman of the House Agriculture subcommittee that oversees dairy policy. "It is 'progress,' because of the potential tremendous profit . . . . It is all a question of greed -- people who can use it will put others out of business. My concern is that we are going to let the big get bigger."

Gene-splicing technology has allowed science to mass-produce a hormone that occurs naturally in dairy cows. Research at Cornell University in New York and elsewhere shows that cows treated daily with BST, the factory-produced protein, increase milk output spectacularly. Four major U.S. drug firms are spending millions of research dollars in an effort to be the first to market BST.

Coelho's comments last week came against this backdrop:

The four companies racing for a worldwide market estimated to be worth $1 billion a year have launched a campaign to win the hearts and minds of skeptical farmers and lawmakers. Their effort includes hiring Gray & Co., Washington's biggest lobbying and public relations firm, and former key Reagan administration officials to help make their case. One of the firms, American Cyanamid Co., flew House Agriculture Chairman E (Kika) de la Garza (D-Tex.) and other legislators to a BST briefing in Pennsylvania this month.

Irate farmers in Wisconsin, the nation's leading dairy state, are campaigning against BST research and development by the University of Wisconsin and protesting the marketing of milk from research cows injected with BST, even though the product does not have the approval of the Food and Drug Administration.

Coelho and Rep. Steven Gunderson (R-Wis.), both from large dairying areas, are making no secret of their intentions to force the FDA, the Agriculture Department and the drug companies to jump through every conceivable regulatory hoop before the growth hormone is marketed.

"I'm not convinced we can pass a law to stop BST," Gunderson said, "but how do we respond to a technological development such as this? As policymakers, we must demand that there be answers to all the questions before we go forward with BST. We support an environmental impact statement and a study by the USDA on the impact that BST will have on dairymen."

After a daylong hearing by his subcommittee on BST development last week, Coelho said that he was distressed to learn that USDA money is going into BST research and that he believed the department was working at cross purposes.

"This is the first time the department is involved in research on a drug that will promote advanced production in the dairy and red-meat industries," he said. "I have no trouble with them trying to deal with diseases and catastrophes, but I question their role in this. I don't think the administration recognizes they are using tax dollars to destroy what we're trying to do on the other hand with the dairy support program. But then, that might be just what they want."

While Coelho and Gunderson raised questions about the impact of BST-produced milk on human health, the FDA has helped spur controversy by approving the marketing of milk on the ground that there is no evidence that BST affects humans.

The agency cited "proprietary information" earlier this month in refusing to disclose how much experimental milk is reaching consumers. But Neal Jorgensen, a University of Wisconsin official, said that when two large experiments are fully under way there, milk worth $165,000 per year will go to market from BST-treated cows.

Reacting to Wisconsin farmers' protests, the university temporarily suspended BST milk sales "in an effort to defuse what appeared to us to be a volatile situation," Jorgensen said. Sales were resumed when officials decided the suspension would suggest that something was wrong with the milk, he said.

Farmers remain bitter. Jim Eichstadt of the Farmers Union Milk Marketing Cooperative in Madison, which has been critical of BST development, said, "We are very surprised that the milk is being marketed. Our question is how the FDA can allow uncertified and untested milk to reach consumers."

On another front, the development of BST has spurred debate about the role of biotechnology in increasing output. Major productivity gains are expected in livestock and plant agriculture as gene-splicing science moves ahead.

"BST is just the first of these products," said Jack Doyle, an analyst at the Environmental Policy Institute. "We simply are not prepared for the productivity burst that is coming in agriculture. The BST technology, for example, really has the potential to destabilize the milk industry, commodity markets and our agricultural policy."

A little known USDA consulting group, the National Agricultural Research and Extension Users Advisory Board, has used BST as a microcosm of the potentially larger problem. Its 1986 report to the president and Congress on budget priorities raised other questions about the impact of BST.

Said William Marshall, an Iowa seed company executive who chairs the board: "What has happened is that we have gone after yield increases almost since Lincoln's time. It made good sense. But now we're just focusing on yields. We will use biotechnology to increase yields, but there comes a time when we need to look at costs."

Marshall continued, "Farmers say it is the increased cost of operating that is killing them . . . . One of our concerns is that the rest of the world will use biotechnology to decrease costs rather than increase yields. But our strong, large agribusiness companies are in the input business and it is not in their interest to cut input costs . . . . Their greed is often in an old-fashioned direction. I would say that by emphasizing yields, they will blow it to the foreign sector that will come in with ways to reduce farmers' costs."