Eruanna - well spotted! That goes to show that not all of us always consider what it says in The Hobbit!
It's interesting too to note that Tolkien mentions butchers here in context. He does not mention them because he wants to tell us about The Shire and its society, but to illustrate something about Bilbo. Tolkien could quite easily have spent several chapters of LotR telling us all about The Shire, how it operates and what the Hobbits do for a living, including butchers, but he does not, he gets into the story quickly. Perhaps it is due to his having already written one substantial novel about Hobbits, or maybe he thought to wrap this kind of information up in the prologue.