These enzymes allow the pigs to digest molecules in their feed that regular pigs can’t; this extra digestion means not only that the pigs are able to get more nutrition out of the same amount of food, and therefore grow bigger and faster, but they also excrete less nitrogen and phosphorus in their waste. More than a billion pigs are produced a year, so the pollution caused by their waste can be a big problem, and genetically altering the animals is one way to address the issue. However, a lot more study will need to be done before these pigs could be considered for commercial use.