I'd advise you to also take a look at task-specific DfM's also...there are probiotics with pathogen-inhibiting strains that will line and colonize the intestinal tract, thereby not allowing the pathogens to attach and replicate...they shouldn't be considered a treatment modality, but are a cost-effective component. Research strongly suggests these microbials are beneficial in controlling a significant number of e.coli, salmonella, and clostridium strains..As always, consult your vet(availability issues noted)...Qualified vets are still difficult to come by in this industry, but we are seeing a bit of an up-tick recently...I'm always reminded of the words of Dr. Grant Rezabek, Oklahoma State Extension Pathologist..."without a proper diagnoses, medicine is poison, surgery is trauma, and alternative therapy is witchcraft"...