The drug, bovine somatotropin (BST), has been adopted as a flagship product for biotechnologists hoping to build a new industry from the fruits of genetic engineering. But the long and controversial approvals processes of European and American safety authorities has delayed its introduction.
In the US, the bovine growth hormone drug gained final approval for sale on 3 February. But its opponents there have persuaded 150 major dairy co-operatives, distributors and supermarket chains to pledge not to sell milk or dairy products from treated cows.
In Europe, the drug is still subject to a moratorium. This had been expected to remain in force until the end of the century, but was recently shortened to extend only until the end of this year.
British safety experts say milk from BST-treated cows presents no extra health fears for people. Opponents have raised concerns over the effect of insulin-like by-products in the milk.
Its manufacturers argue that BST allows fewer cows to produce the same amount of milk, reducing costs for farmers. But the National Farmers Union says animals that are lactating for longer and producing more milk will need more feed. Opponents claim BST raises the incidence of mastitis, a disease of the udder, in cows on the drug whose milk production it can raise by as much as 20 per cent.
A survey published today by the Food Commission, a campaigning organisation for 'clean' foods, says that Sainsbury's is prepared to ban the sale of milk produced using BST even if it is legalised in Europe because of the animal welfare implications and questions over the economic need for the over-production of milk. The chain is also reported to be planning new labelling guidelines in May on all genetically engineered foods, following a similar move by the Co-op earlier this year. The Co-op is opposed to the production and sale of BST milk.
Safeway and Marks & Spencer are reported as saying they follow government labelling guidelines on such foods - these require only certain categories to be labelled. Neither proposes to sell milk from BST-treated cows because they see no benefit to consumers. Asda told the commission it thinks the milk should be labelled to promote consumer choice.
A spokesman for Elanco, the agricultural veterinary division of Eli Lilly, one of Europe's leading BST developers, said his company had focused on getting the drug approved. It will now concentrate on persuading the public, farmers, milk suppliers and supermarkets that BST is desirable. This, he acknowledged, would be 'a big task', but he anticipated that 'logic will prevail, rather than emotion'.
The Milk Marketing Board, due to be privatised and become Milk Mark on 1 November, has yet to form a policy on BST. But it and any competitor organisations that enter the market then will play a crucial role in determining the success of BST, especially if pressure from consumers or shops persuades them to stipulate that suppliers do not use the drug.