Coccidia is spread in the feces so anything that will reduce fecal contamination will help. Feed hay in racks, not on the ground. Make sure the water containers are clean. Clean the barn regularly and make sure the bedding is dry.
Baycox, active ingredient Tolturazil.
Get it from your vet or order it online. I use 1cc per 5lbs at 3 weeks, then once a month until weaned, but I live in a very parasite-heavy area - wet ground and lots of wildlife.