In Animal Farm, the milk and apples symbolize the unfairness of the system that the pigs run. In a larger sense, the milk and apples symbolize the graft that the communist party elite, including Stalin, carried out in the Soviet Union.
In Chapter 3, the animals learn that the pigs take the farm's milk and fallen apples to combine in their food each day. The other animals had thought that the farm's provisions were to be shared equally, and they object. Squealer, sent by the other pigs to explain why the pigs get better provisions, says:
"You do not imagine, I hope, that we pigs are doing this in a spirit of selfishness and privilege? Many of us actually dislike milk and apples. I dislike them myself. Our sole object in taking these things is to preserve our health" (page 14).
Squealer says that the pigs dislike this better food, but they make a sacrifice to eat milk and apples because they are the "brainworkers" and are essential to organizing and managing the farm. He also says that the pigs need this richer, better food because the whole farm depends on them. In addition, Squealer does not hesitate to remind the animals that they don't want Jones to return; he mentions Jones's name so that the animals stop complaining about the pigs when they recall how much they hated the old days. This is a reference to the tendency of the communist elite to justify their receiving more perks than other people and to distract people from this unfairness by referring to the injustices of the old system of the czars.