You say you used “medicated” feed. Everything I have read says to use “nonmedicated” starter at 19%. Mix water to make a mash for about a month. Then switch to the same mixture you use for your adult swans. Keeping them on starter for too long could make them grow too fast creating leg issues. They will be so heavy so quickly their legs can’t keep up. I agreee as well with the regal swan reply as well. I expect about a 10% mortality rate when raising my swans. Hope this helps:)