Mine get things about once a week. They usually get things like goat ribs, sheep ribs, duck necks, beef knuckles, and whatever venison or hog parts we have leftover.
I buy all my meat once a month at a awesome little butcher/meat market and the guy who owns it always throws in the goat, sheep, duck, whatever and occasionally some pork hocks and pig snouts and tails. I have to vary my days up when I go because I swear the dogs were starting to realize what day on the first of the month I went.