Now, we all know that there’s nothing children appreciate more than a fart joke. But — and this is a deep philosophical question — does that mean every animated film has to have one? It’s been a long time since I’ve read Orwell’s novella, but I don’t think there was a moment in which Napoleon (Seth Rogen), the Saddleback boar who becomes the villain of the piece after rising to power on the farm, lets loose a big wet one and exclaims: “This is the sound of freedom!”