BST-usage causes public health concern
The use of bovine somatotrophin (BST) poses a potential risk to public health, according to the Scientific Committee on Veterinary Measures relating to Public Health. The warning, which appears in the organisation's report of 15 and 16 March 1999, follows close on the heels of a recent statement, by scientists of the European Union (EU), that BST should not be used in dairy cows on animal welfare grounds. BST, a synthetic, genetically engineered substance is based on a cow's naturally occurring growth hormone. It is injected into cows every two weeks to increase milk production. But, according to recent scientific comment, its use may increase the concentration of Insulin Growth Factor I (IGF-I) in milk. This is cause for concern, as recent epidemiological studies have indicated that IGF-I is associated with an increased relative risk of both prostate and breast cancer. Further research into the links between IGF-I and cancer is therefore necessary, and scientists have stressed that the amount of IGF-I in the milk of cows treated with BST is currently unknown. The independent scientists also referred to other potential risks of the use of BST. These include increases in allergic reactions, as well as an increase in the use of anti-microbial substances to treat of BST-related udder infections. This could also lead to residues of BST building up in milk, which, in turn, could increase the selection of resistant bacteria. On 31 December 1999, an EU moratorium, which prohibits the marketing and use of BST, will expire. The two reports - from the EU scientists and the Scientific Committee on Veterinary Measures relating to Public Health - will provide an essential basis for the forthcoming review of this prohibition. The Scientific Committee's report will shortly be available on the website below.