It is about how Perry feels almost envious (!) of pigs, because they are closer to paradise than he will ever see. They don't worry about love or other peoples opinions, if they want to fuck, they just go for it, they don't care about how they look and a pig is never happier than when it is rolling about in it's own shit, basically the only thing that is genuinely free. He also talks about how we are not truelly free as long as we care about others, because we are restrained on some level due to our feelings of responsibility to other people, something a pig doesn't have, a pig doesn't care that there are others in pain around him, as long as he is ok.
It is about how Perry feels almost envious (!) of pigs, because they are closer to paradise than he will ever see. They don't worry about love or other peoples opinions, if they want to fuck, they just go for it, they don't care about how they look and a pig is never happier than when it is rolling about in it's own shit, basically the only thing that is genuinely free. He also talks about how we are not truelly free as long as we care about others, because we are restrained on some level due to our feelings of responsibility to other people, something a pig doesn't have, a pig doesn't care that there are others in pain around him, as long as he is ok.