R.L. Boddie

Evaluation of teat germicides of low iodine concentrations for prevention of bovine mastitis by Staphylococcus aureus and Streptococcus agalactiae

Abstract Two iodophor teat germicides of low iodine concentration were evaluated in a controlled, experimental challenge-infection study against Staphylococcus aureus and Streptococcus agalactiae . One germicide was a 0.1% iodophor containing 0.75% glycerin, formulated to maintain 5–6 ppm free I 2 . The other germicide was a 0.175% iodophor without emollient, formulated to maintain 4–6 ppm free I 2 . New intramammary infections with Staphylococcus aureus and Streptococcus agalactiae were reduced 80.7 and 56.6% by the 0.1% iodophor. The 0.175% iodophor gave a 65.0% reduction in new Staphylococcus aureus intramammary infections, but the new infection rate for Streptococcus agalactiae was low in both control and dipped quarters and provided limited power to detect differences between treatment groups. Reduction in new Streptococcus agalactiae infections was 33.3% for the 0.175% iodophor. No adverse effects on teat skin condition were observed.