I have four chicks, all 2 weeks old. The Light Sussex had a cocci infection that is now resolved, but she just doesn't seem to be growing like the others. The Welsummer chick has wings that go all the way to her rump, she has a few tail feathers, and some feathering coming out on her shoulders and the sides of her rump as well. She also has a nice little comb. The Barnevelder chick has slightly shorter wings, a few tail feathers, and feathering starting to come out on the shoulders. She has the tiniest of combs starting to show. The Ancona chick has wings that go all teh way to her rump, a few feathers coming out on her shoulders and a small tail feather starting to show. Her comb is smaller than teh Welsummer, but bigger than the Barnevelder. BUT.... the Light Sussex chick looks the same as she did when I got her, only a bit bigger. She is covered in down, her wings are tiny stubby things that don't even come halfway to her rump, all the rest of her is still fluffy down - not a hint of tail feathers or anything else. She is also a lot smaller than the rest and no comb at all. They all looked much the same when I got them... 2 or 3 days old, all quite downy with small wing feathers and no combs. Is it possible the cocci has knocked the Light Sussex back and stunted her growth or is this breed generally slower maturing than the others?