My week old Isa brown is having troubles. Her poo is super dry and clumps up at her exit. I pulled it off (along with some fur) yesterday and today it was back! She isn't eating, and she's the only one in the bunch who isn't growing on pace with the group. I pulled the poop off again, and she just sits alone while everyone else rushed the feed. I'm feeding them chick starter only. Should I include some sand for grit? Are the two related?