Science searches for a 'happier' pig
Scientists are trying to genetically engineer happier pigs.
They say that nasty ones, which bite and gore their fellow animals, reduce the amount of ham farms can produce.
If researchers can find the gene which makes pigs bad they think they can remove it and boost productivity in the herd.
Allan Schinckel, professor of animal science at Purdue University, Indiana, based his claim on his work with aggressive chickens.
Professor Schinckel said: "The more pigs you have in a pen, the slower their growth rate due to stress and aggression.
"Even having them together for 48 hours slows the growth rate of the pigs for two weeks."
