The manipulation of animals by humans knows no bounds.

I have read about the possibility of breeding "pain-free" GM animals. An American philosopher has said: "You could eat meat but avoid animal suffering... making meat-eating more ethically acceptable."

Surely this statement is an admission that animals experience physical pain while being reared and slaughtered for meat and that eating meat is ethically unacceptable.

If experiments being carried out result in the breeding of "pain-free" animals, an issue not addressed is their emotional lives. All animals bred for food, particularly those in factory farms where most of our meat is reared, are denied the chance to live and behave as Mother Nature intended. Their natural instincts are annihilated.

Cruel practices abound: tails are docked; teeth and beaks are clipped to avoid mutilations caused by sheer frustration. Offspring are taken from mothers. Intelligent, fastidious pigs have to stand in their own faeces and urine.

As long ago as 1969 Sir Julian Huxley and nine fellow scientists wrote: "It is obvious that behavioural distress to animals has been completely ignored. Yet it is the frustration of activities natural to the animal which may well be the worst form of cruelty."

Approximately two million animals are slaughtered every day in British abattoirs. So much physical and emotional suffering is unacceptable and unnecessary.

Elizabeth Allison, Aylestone.