It is better to treat them better with chemicals and stuff, because they could enjoy the last moments of its life. When they are happier, their brains release endorphins into their systems, so the consumers will also feel more happy when they eat it. And then they will subscribe or call the slaughterhouse company more often, and the company will make more money. So in the end, everybody and animals are happier.
People eat too much meat anyways. I'm not a vegan or even a vegetarian but I do try to keep a balanced diet (and probably still eat too much meat). If requiring humane treatment for animals has the side effect of raising meat prices then it is a positive side effect.
Why should it even matter what conditions miss piggy lives in before she's fried? Animals ain't got no feelings. There are animals living in mucho more worse conditions than the chicks and pigs in those slaughterhoses, why not focus on those first? Also, there are much worse problems that deserve our ateention much mor than them pigs and chicks