Pig apple? Is that bad apples that are fed to pigs? Why would you need to rate those? Aren't they just, by definition, lowly rated apples?

maybe it's the apple you use in the pig roast?

the apples that are so far gone with worm/larva frass I called "deer apples". Because I could make a pile and the deer would take them. I've also seen deer "climb" trees to get apples.

Well, the pigs have preferences too