It's harder to get a precocial chick to open up. In pigeons (haven't had the chance to own chickens yet), I generally wrap older squeakers who are not used to being hand-fed in a towel. That helps limit struggling a whole lot. Just don't put pressure on the breast area as that will limit breathing sometimes to the point of death. Putting pressure from above right above the wings is far more effective anyway, even in large, strong birds. Use your fingernail inserted in a way that it matches the natural curve of the beak, open, and use a pinky to keep open. At the very base of the tongue, there is a raised area around a hole. That is the glottis leading to the trachea and lungs. Do not get any food or liquid down that hole! Chicks that aspirate can die in minutes...nerve wracking, I know, but important to know. You can either stick food using liquidy formula through a syringe or smallish food pieces to the left of the mouth (your left), or you can put food near the tip of the beak and encourage the chick to swallow. Sometimes, for whatever reason, I find stroking the back of the neck can help stimulate the muscle so they peck more diligently. If that fails, if you still wish to feed at that point, you are looking at depositing food directly into the crop through tube feeding. There are some directions here:
http://forum.backyardpoultry.com/viewtopic.php?t=7933
It's easy enough to kill birds with this method (feeding food that is too hot, too cold, not enough liquid causing crop to impact, puncturing crop lining, aspirating, etc), so if you have someone who can show you how to do this in real life, that is really helpful and can lessen the feeling of guilt if something goes wrong. I agree with some that it sounds like this chick is not doing well. If it does not improve after receiving food, I personally would consider euthanasia. Regardless of what you decide, thanks for caring about and caring for this chick, and best of luck.
