A few months ago, my ladies got some chronic respiratory disease that was mild, but caused them to stop laying for a few months. They have since recovered (a few still have occasional sniffles, but can't be treated). They went thru a light molt, then about 1/2 started laying again (finally!) I now have about 20 out of 30 laying (I get about 15-18 eggs a day). I am getting the same eggs each day from the same chickens, so i know that the ones that are laying are laying nearly every day, and the others aren't laying at all (it helps to have brown, blue, and white eggs!) There must be something I can give them to boost their immunity???? Like vitamins? Or some holistic chicken diet? Their feed is good, high protein, free-range, etc. I think it's mostly my auracanas that aren't laying (I have 6 blue layers and only get 1 blue egg a day). These ladies are only 12 months old, so they should be producing very well. I know it's the myoplasma or the Chronic Respiratory disease that's caused this and some say there is nothing i can do, but I am hoping for the immune booster to help. Cuz half of them are fine, so why aren't the rest?