Hygiene in the prevention of udder infections. III. Effectiveness of 59 teat dips for reducing bacterial populations on teat skin.

Fifty-nine teat dips were tested for effectiveness in reducing populations of experimentally applied Streptococcus agalactiae and Staphylococcus aureus on teat skin. The results varied widely among products. Populations of S. agalactiae recovered from dipped teats ranged from a 98.3% reduction to a 147.4% increase as compared to undipped controls. Reductions in recoverable S. aureus ranged from 98.5 to 43.6%. The products yielding the highest germicidal activity did not conform to a consistent pattern in type and concentration of active ingredients, presence or lack of specific emollients, or pH. Approximately 20% of the products yielded a low activity. Each of six oil-based products performed poorly and frequently increased numbers of organisms.