Screening tests for new teat dips

Increased use of after-milking teat dips has resulted in the appearance of many new teat dips and a need for methods of evaluation of efficacy. A method was developed for determining the ability of a disinfectant to kill bacteria on the teat ends. Results from several known efficacious products indicated an approximate 95% reduction in bacterial flora. Additional data are presented on some experimental products. This method will provide a measure of effectiveness of a producton teat-skin disinfection. The effect of some changes in the testing procedure on bacterial reduction is demonstrated: 1) Increased times between inoculation and dipping and between dipping and swabbing tended to decrease recoveries on control teats. 2) Saline dips on controls teats provided increased recoveries of test organisms.