Genetically engineered pig. Conceptual image representing the rearing of giant genetically engineered livestock. This giant pig is being presented with a similarly huge acorn to eat. Genetic engineering involves altering the DNA (deoxyribonucleic acid) of an organism to promote desirable traits. Human DNA can be introduced into a pig to enable organs from the pig to be transplantable into humans. Combining the DNA of different species is known as transgenics. Potentially, genetic engineering may be able to make an animal produce more meat and survive on less food, giving farmers a greater profit margin.