Scientists refer to these creatures as 'knock-outs'. In 1982 giant mice were produced by incorporating human growth hormone genes into the animals' fertilised eggs. Animal Suffering Animals suffer not least because scientists cannot predict the results of their genetic tinkering. The large-scale animal suffering flowing from th e 'genetics revolution' has been largely uncharted, with examples of animal s being born with a virtual loss of limbs, facial clefts and massive brain defects. The 'oncomouse', produced by inserting human cancer genes into the embryos of mice, quickly develops fatal breast cancer, whi le genetically engineered 'cystic fibrosis mice' die within 40 days.
Much genetic engineering is aimed at getting farm animals to grow bigger and more rapidly.
Other side effects include indigestion, bloat, diarrhoea, leg and foot problems and anaemia. Human consumers ar e also at increased risk of contracting breast and gastro-intestinal cancer , according to Samuel Epstein, Professor of Environmental and Occupational Medicine, University of Illinois. Another application is to develop new 'animal models' that more closely mimic human illness. Using transgenic and knockout mice, researchers have created animals with neurological disease, cancer, cystic fibrosis, sever e arterial plaque, sickle-cell anaemia, liver damage and many other conditions. But whatever miracles the new technology hopes to perform it cannot transform mice into miniature people, and the results cannot be relied upon.