The molting is specific to the climate, temperature or area altitude change. When birds molt the big feathers they are making room for more of a down base and when they are molting the down feathers they are to hot for the area they are going to be in. They will constantly change feathers according to how the weather is or if its time of the year like turning to summer or winter coming on the genes just know what to do and what they need. The balding if it were on one specific bird could mean another larger bird had been picking on that bird but since all of them have equally the same feather issues I doubt that its been picked on or all have been picked on. Do not put heat on these kids they will not need it if they are older than 8 weeks.
The vitamin deficiency can be solved very easy with adding liquid vitamins to the water like Vita-Sol and apple cider vinegar organic can be purchased at any health food store and only needs to table spoon it into the water. DO NOT WORM THESE BIRDS unless you see signs in the stool and before you worm them with any worming medicine have a vet check for you first. You will do more harm than help if they are wormed and no worming is needed. One way to help in stabling the birds and you did not say whether they are young, juveniles or layers so I am guessing they are over 10 weeks but feed them medicated chick feed. That will benefit them greatly until about 20 to 24 weeks. Put down proteins like eggs (scrambled or hard boiled) flax seeds and dairy products such as yogurt cottage cheese. It would also benefit them to offer leaf vegetables and fruits such as melon. I would make up a sand bath with sand/dirt mixed up with food grade DE (diatomaceous earth) by mixing 10lbs of DE and 30 lbs of dirt/sand or 1/3 to 2/3 mix. It will help kill any mites and lice infection on the skin and when they pick and scratch and eat at it the benefit will be good for the digestion and fill the crop of the birds with sand and the DE will help flush the intestines of any bugs that may have settled in the digestive tract. It can be helpful to force any worms to leave the entire digestive tract also. The only challenge that I still see is the birds with the cross beak and they will be a challenge. They can still have a normal life but with special handling depending on the severity of the cross beaks. In some extreme issues the bird needs to be culled. Then again in a minor cross beak the chicken can with help lead a normal life if it is not having feeding issues and the other hatch mates let it eat normal or you place separate feeding bowls down for them to eat. Best of luck to you with the kids.
I have had two cross beaked chickens before. It wouldn't be nutrition-related after they were hatched. IDK if it is genetic or nutritionally related (for the hen before the egg is laid).
What I would recommend is to definitely check them over for mites/lice and dust them if needed, retreating at 10 days for mites/2 weeks for lice.
Additionally, I would feed them lots of protein...consider feeding them scrambled eggs and plain unsweetened yogurt for treats.
You might consider even buying a 20% nonmedicated chick starter feed and giving them oyster shell on the side for calcium until they have grown their feathers back. Making new feathers requires a lot of protein. This will help them through their molt and hopefully get them laying again faster.
Molting is very hard on hens.
In terms of heat at night, if you are giving them a good coop that has no drafts but good ventilation (no air blowing directly on them) they should be fine. But you know your setup better than anyone else. I do give heat (100 watts) when we go below freezing.
Thank you both SO MUCH for the advice! I did forget to mention that we were told by the previous owner that these gals were about 18 months old. My husband went and picked them up and reported that these were the "reject chickens." I came home from work to find a cage full of nearly bald, shivering, rather goofy-looking hens. I also failed to mention that I already had 6 chickens that are about 9 months old, I raised them from hatchlings and have not experienced molting yet.
I brought the cage full of new girls into my bedroom and covered it with a blanket; they stopped shivering after that. Daytime temps here are in the 50's so I've been putting them out during the day and bringing them into the bedroom each night when temps are in the 20's. Will they get sun-burnt?
The cross-beaks seem pretty severe to me, but then I'm a novice and have never even seen a cross-beak before now. The 2 cross-beaker's are about the same size and weight as the others, so I guess they are able to eat OK. They spend ALL day at the feeder though so I think it takes everything they've got just to get enough to get by. I need some seriously detailed advice on trimming their poor little beaks. Maybe that would make their lives a little easier.