I'm not just doing an ad for Poultry Nutri-drench. The stuff is formulated for sick chickens and it gets right into the blood stream without having to go through the liver. In a FTT chick, this could mean the difference between life and death since their liver may not be fully operational.
It will give the chick a quick boost of nutrients, and if it has any chance of making it, this will give the chick the energy to begin eating. I had such a chick a few years ago, and it revived on Nutri-drench and began eating again. In two days, it was competing for food with the other chicks like a demon. The transformation was that dramatic.