SIR - Philip Bird (T&A, May 1) claims that thousands of animals would have to be slaughtered if we all became vegans.

Firstly, what happens now? Millions are slaughtered annually in the UK alone. Secondly, any change would be gradual, so the number of animals reared would be correspondingly reduced.

At least one quarter of the earth's land mass is currently used in producing meat, and half the grain produced is fed to livestock.

Veganism is a viable solution for the future of mankind, other species and the environment on this planet, making the best use of limited natural sources.

Cynthia Trasi, Kirkgate, Shipley