Effectiveness of an Internal Teat Seal in the Prevention of New Intramammary Infections During the Dry and Early Lactation Periods in Dairy Cows When Used with an Intramammary Antibiotic

Abstract

The practice of blanket dry cow antibiotic therapy has been very successful in eliminating many existing infections at dry-off and in preventing new intramammary infections (IMI) during the dry period. However, many new intramammary infections still occur during the dry period due to factors such as delays in keratin plug formation, poor sensitivity of some invading pathogens to intramammary antibiotic preparations, and decreases in antibiotic concentrations near the end of the dry period. The primary objective of this study was to describe whether quarters treated with an internal teat sealant in addition to an antibiotic (treated) at dry-off would develop fewer new intramammary infections during the dry period and early lactation, as compared to quarters treated with antibiotic alone (control). Secondary objectives were to describe the effect of treatment on the prevalence of intramammary infection after calving, the incidence of clinical mastitis events between dry-off and 60 days in milk (DIM), and linear score (LS) after calving.