Lord help me!!!!!!

[tinman9952]

I'd consider butchering them now.

 

[Settin'_Pretty]

Sounds to me that the vet told you the problem, impacted crop from lack of grit.
Miss Prissy is also right, those roosters need separated from your layers.
ALL chickens need grit, it's their "teeth".
Calcium (oyster shell) should be in a separate dish, as should grit and not mixed in the food, so the birds can get it when they want it, IF you start seeing a calcium deficiency, then you can sprinkle a small amount in with their food.

I suspect your roo's are younger birds and up until adding them to your pen, conditions were acceptable in the pen for the three hens.

Chickens are pretty good at taking care of themselves if they have what they need available to them.

I always kept the layer feed in a feeder filled and then threw a couple handfuls of scratch in the run every morning to give them something to do all day long, and a "rabbit feeder" of grit and one of oyster shell, hanging on the fence filled for them to get when they wanted or needed it.
And they did.