Evaluation of .5% and 1% iodophor teat dips on commercial dairies

Two postmilking teat dips containing .5 and 1% iodine were evaluated for approximately 8 mo under conditions of natural exposure to mastitis pathogens on four commercial dairy farms. In the two herds using .5% iodophor, incidence of intramammary infection with Staphylococcus aureus and Streptococcus agalactiae was reduced 68.3 and 46.2%, respectively. When numbers of new infections with both pathogens were combined, efficacy for the .5% iodophor was 62.3%. In the two herds using 1% iodophor, incidence of intramammary infection with Staph. aureus and Strep. agalactiae was reduced 52.4 and 70.7%, respectively. When numbers of new infections with both pathogens were combined, efficacy for the 1% iodophor was 64.3%. Efficacy of teat dips was variable against coagulase-negative staphylococci and Corynebacterium bovis.