Could you expand on the leg deformities and cure? I'm curious.
It was less a matter of deformities than it was of disability. In my second batch of Serama chicks, the smallest one ran out of room to grow in its egg. That egg was half the size of the others. The chick is still much smaller than the other two, but thriving.
That chick's legs stuck straight forward. He didn't flip over on his back - he just scooted around on his butt and belly, kicking his feet in front of himself and using his wings to 'swim'. I use a vitamin powder that's all-stock, but has a very good array of vitamins in it, and electrolytes.
This stuff;
https://www.agrilabs.com/products/vitamins-electrolytes-plus
The key ingredient there that was looking for is something that Nutridrench does not appear to have, which is why I haven't bothered to get any. Namely, Vitamin B2: Riboflavin. From what I've read - I'm no expert! - a Riboflavin deficiency can result in leg problems in newly hatched chicks.
I used a q-tip to the side of the beak soaked in the vitamin-infused water - I just add it to their waterer, so everyone gets it - to get the vitamins into the chick and be sure it was eating. That Serama chick, I also would put in a saki cup for about fifteen minutes at a time, a few times a day, to make him hold his legs underneath his body - he was so small that he had to stand up to see out, and of course, chicks always want to see out. Within a couple days, he was upright on stiff legs, and the next day he was running around normally.
The last batch of eggs, the muttly chicks, I had two chicks who kept their feet curled up. They were unable to effectively walk, and sort of hobbled around on their hocks. Imagine trying to walk only on the sides of your feet - that's what they were doing, with the outside toe curled in and under. Both of those chicks came from similar eggs, and have similar coloration/markings, leading me to think they were probably laid by the same hen.
A few days of vitamin water with riboflavin in it, and they were both walking normally. I put them outside at three days old, with heat at night (too hot during the day for additional heat). I noticed that the smaller of the two was seeking warmth faster than the rest, and huddling when it started to cool off, so I added the vitamins back to their water until they were two weeks old.
They are currently - as of today - four weeks old, fully integrated into the flock, no longer in the chick pen - I have my injured one isolated inside it, where the rest can't pick on her - and doing wonderfully.
Edit to add - a third egg has pipped.
