Dipping of cows at dry off and cows and heifers 10 day prepartum until calving with a persistent barrier teat dip product (developed and patented at ISU) in 2 natural exposure field trials resulted in a significantly lower IMI (particularly major environmental pathogens) at calving compared to controls. Dipping and/or dry therapy resulted in significantly lower new IMI in the early dry period compared to controls, with no difference in new IMI between treatments. Dipping of cows with a new persistent barrier teat dip provides the first cost effective, novel dry cow mastitis prevention tool focused at high susceptibility times and all causative organisms, and also can be a potential substitute for dry cow antibiotic therapy for prevention of new early dry period IMI. This also results in lowering the potential risks of antibiotic contamination of milk.