Currently I'm giving manna pro oyster shell free choice. My girls bill it out to find the smallest pieces, leaving much of it on the floor of the coop and on the ground in the run. The only ones I ever see at the shell feeders are my leghorns. My partridge rocks have thinner shells. Otherwise they get layer pellets. I tried scattering some on the ground around the yard to see if they'd eat more that way, but they don't. They love crushed egg shells though, and clean them up every time I give them. Are there any other brands that have smaller bits of oyster shell? Have any of you ever had this problem? I know the stuff isn't that expensive, but I hate to scoop half of it up in the shovel when I clean out the coop. Just seems so wasteful to me.