LETTERS: Science holds key to veal debate

From Professor N. Kurti, FRS Sir: Emily Green's and William Waldegrave's thoughtful and constructive contributions to the "veal debate" (3 January) should be read in contribution with Tom Wilkie's excellent article (10 January) based on a conversation with Professor Chris Polge, of Cambridge, one of the foremost experts in this field. It seems that, by the method outlined below, a dairy herd can be maintained without reducing milk yield or producing calves not suitable for beef.

1. For maximum milk production, a cow must calve every year.

2. On average, dairy cows must be replaced every four years, hence one quarter of the calves born must be, say, Holstein females, while the remaining three quarters should be, say, Aberdeen Angus.

3. It is now possible to separate sperm into its "male-producing" (XY) and "female-producing" (ZX) chromosome components. But the yield is too low for use in artificial insemination.

4. The answer is "in vitro" fertilisation: Holstein embryos and Aberdeen Angus embryos in a proportion of one to three to be implanted into the dairy cows.

5. The success rate at present is only about 30 per cent, but if this could be increased to 70 per cent, the method would become viable.

A couple of years ago Mr. Waldegrave, as Lord President of the Council, in charge of scientific research, offered a bottle of champagne to the author of a brief A4 explanation of the nature and the importance of the "Higgs Boson", the search for which was one of the justifications for the expenditure on the Cern particle accelerator. Now, as Secretary of State for Agriculture, he might offer a similar award to the author of a concise and convincing statement about the possibility and the cost of an early solution of the "veal crisis".

Yours faithfully, N. KURTI Department of Engineering Science University of Oxford Oxford 17 January