Cloned cows healthy

A study of 30 cloned cows in the US has found that the majority of them are healthy and have no signs of the physical abnormalities that have affected other cloned animals. The study was undertaken by scientists from the Mayo Clinic, Pennsylvania, and three other companies involved in animal cloning, including Advanced Cell Technologies (ACT). Six of the 30 cloned cows died shortly after their birth, but the remaining 24, aged between one and four years old, were alive and robust. The researchers fund that the cows' immune systems were normal, they sexually matured at the appropriate time, and two of them had given birth to normal calves.

The authors of the study warned against the results of this study being taken as encouragement by would-be human cloners. The study had been of an experiment from which there resulted 110 pregnancies. Nearly 75 per cent of the cows spontaneously aborted, and one of the calves that died soon after birth failed to develop an immune system at all. Ian Wilmut, of the Roslin Institute, believes that the results of the study are 'encouraging', but that this evidence 'surely confirms that it would be irresponsible to attempt to clone a person'. He also said that 'it raises the question of whether there should be widespread use in livestock production until the technique is more efficient'.