I switched from flock raiser to dumar (20%) chick/duckling starter/grower, adding ground down shaken niacin into water (it doesn't mix well normally a pharmacist told me), and add nutridrench poultry vit and min conditioner. Mostly ducklings getting better now, but on still bowed in legs, one still bowed in legs with joints loose and stuck out so looks lik pontoon boat, one with swithed leg and foot sorta backwards and out. i got hold of very patient lady at purina who took all the info down, and said they'll be doing a thorough investigation of the line ect and keep me involved.