What special treatment did the pigs get?
This really depends on what part of the book you are in. At one point early on, the pigs receive apples and milk in addition to their simple mash that they used to have.
The pigs don't have to work, when everyone else does. The pigs eventually occupy the house and the rules are changed to fit what they would like to do in the house, like sleep in the beds. They eventually wear human clothes, and eat off of the human dining plates.
The best lines of the book occur in the last chapter when the author reports how similar the pigs become to the humans they tried to rebel against.
Over the course of the book, the pigs get all sorts of special treatment that show that they are "more equal" than the other animals.
We can see this starting out very soon after the rebellion. At that time, we see that all the milk from the cows gets reserved for the pigs. We also see that only the pigs get the apples.
Later on, we see that only the pigs get educated. Only the pigs live inside and only the pigs get to drink the whiskey when the whiskey is found.
In other words, the pigs get all the good stuff...