boosting up weight quick????

[EngTeach]

Is there something I can give my bird to make sure he's getting the right nutrients while going through rought patch? I've posted on another thread about his plucking until he has bloody sores....and he's now wearing a collar until he heals up ....or longer. But his eating is off. He's eating his Zupreem fruity pellets....just not as much as usual. He refuses to eat any veggy or fruit other than bits of apple (another behavior problem that I'll tackle after he's well). I just thought maybe there was something for birds....like Nutracal is for dogs that will help him maintain weight while going throught this rough time.

Let me know if you know of something. Thanks