I think it's the split antlers that go pretty quick. Ralphie's got about half of an un-split deer antler still left to go that's about 6 months old. I bought him a split elk antler last week, though, and there's only a little stub of it left.
Ralphie - GSD, rescue, Gotcha Day 2/10/13
Nightshade - born 6/3/2003 - Domestic medium hair/Maine Coon mix (feline)
James - Domestic short hair (feline), rescue, Gotcha Day 6/23/11