At stake is consumer acceptance of dairy products made with milk produced by cows treated with the drug.

A23 Five major food sellers will ban milk from cows treated with an experimental genetically engineered drug.

Indeed, they find it indistinguishable by any known analytic test from milk made by cows not treated with the hormone.

The problem was halted after the farmers stopped adding the milk of the cows being treated to regular milk supplies.

The state also established an official label to be placed on dairy products that are produced from cows not treated with the genetic hormone.

Yet in August, five major supermarket chains refused to carry milk from cows treated with the drug because of pressure from consumer groups.

Some of the nation's largest supermarket chains and dairy cooperatives have refused to buy dairy products from cows treated with the drug.

The company said 36 cows treated with the drug had died, and 14 farmers had reported problems with mastitis.

He said no special labels would be required on milk produced by cows treated with the drug.

The group said in a statement that increased risk of infections in cows treated with the drug was almost 80 percent.