I normally crush egg shells for my 3 girls. Guy I know said to do that and skip the oyster shell. We live off the grid and are working to live off the land so the more natural and easy to obtain the better. I have not wormed anyone all year though. I have a large flock of wild turkey that come through sometimes. Maybe they brought something into my lawn?
In regard to the "vomit" I think you are right, eggsighted4life, about the burping but its always after he drinks and its only water that comes up. Again it doesn't happen, that I see, every day.
I do still have grower crumb from my guinea hens. I'll give them all that and some scrambled egg for my roo. They get quite a bit of garden scrap like tomatoes, squash, zucchini. My fiancé works at a little bakery and sometimes brings them home breads and bagles. I give them that sparingly though.