I keep deep litter in my brooder pen and reuse the already inocculated litter for other batches. If I clean it out, I leave a base layer of the original. Just like exposure to mama's germs, IMO. I've never used medicated feeds and I'm sure I'm not the only one with soils and a flock that has absolutely no cocci bacteria. No such thing, so I'm not just lucky with this method...it works.
