Manna Pro® 0094669906 Advance® Microbial Provance Supplement For Calves, 30 CountEach bolus contains a source of at least 40 billion live viable naturally occurring microorganisms that help promote a healthy gut. These microorganisms populate rapidly to overcome the illness promoting pathogens of the gut. 30 count Each bolus contains a source of at least 40 billion live viable naturally occurring microorganisms that help promote a healthy gut. These microorganisms populate rapidly to overcome the illness promoting pathogens of the