We mix about 1 cup of 10g crumbles per 50lbs of feed. I don't think it would hurt fawns nursing their moms even if you over do it. Any of my deer will get lose stool if I add to much. Aeuromycin in my area is most commonly available in 2g,10g, and 80g crumbles. We use it more as a preventative and not as a treatment for anything specific. It also seems to help in the spring with weight gain.
If you read the Kerr study Jerri Lee posted under Sucker tines setting industry records their feed recipe is described in detail more than once. It was developed by the PhD's, DVM's, and biologist working at the facility. They give the amount of Aueromycin used continually in their feed recipe. You could calculate your questions answer from that data.
Good luck