Just take those back if you can, and get vitamin E 400 IU and Vitamin B complex which has most of the B’s including thiamine, riboflavin, niacin, and others. The mg can vary on the vitamin E, but look for 400 IU.
Great advice from everyone. Selenium is only needed in a small amount, and it is already in the chicken feed, plus a bit of egg, tuna, or sunflower seeds once a day would have plenty. Hopefully, your hen just has a hereditary tendency toward wry neck symptoms. It seems to be very common here, in...