The chick starter has some grit in it. If thats all they are eating, they will be fine. My Cornish Cross are in a pen...outside..on the ground. They dust bath...peck in the dirt..and eat small blades of grass. I dont give them grit. As for the " lump" thats just a full crop...nothing to worry about. Just means they are eating well. With Cornish, thier crop will be full MOST of the time especially if you are free feeding. As they will just eat, and eat, and eat, poop, and poop, and eat some more! LOL Just make sure they have PLENTY water. Those little buggers can really go through it. I have a pen of 21....they drink about 8 gallons a day....some days even more if its slightly warm outside.