Mystery Meat Being Mysteriously Mysterious

In more recent years it has been found that feeding farm animals corn is more more affordable than feeding them food that's actually designed for their bodies. Genetics asks for cows to graze on grass but farmers are being taught to feed them corn. Why not? According to Food Inc., the government gives money to produce more corn than what is needed. Why waste money on making farm land available for cows to graze as they please when there's all this extra corn to feed these animals? When corn fed to cows doesn't digest properly the cows get sick and they develop a type of e.coli called 157H7. So now everyone that eats that cow will become sick. But it's not as if the e.coli stops there. Since cows don't get the opportunity to roam and eat, farmers keep them in a small cramped space where they pretty much live in their waste. In the movie Food Inc. it's shown that the farm land for cows is in areas in which trees were dug up to fit the cows. When land is destroyed like that, it can't protect itself and when it rains it'll flood. So that e. coli that the cow's infected with? It's in its waste and that waste gets washed away in rain water that eventually leads to a larger water source. And then that water might wash up on some healthy cabbage or tomatoes. Now people that eat those vegetables have e. coli. Whoever eats any of those cows have e. coli. It's like the gift that keeps on giving. I understand that it's cheaper to feed cows corn. That's great it's good for the economy. Double great because corn makes cows fat and fat cows means more meat being sold and who doesn't love the sound of a more money? But is it really fair that these cows are sick and then people that eat them are sick? Is it fair that people don't even have to eat the meat to get sick? Come on USDA. You guys are in charge of everything that involves meat from when they're babies to when they go on people's plates. Somebody do something.