Hygiene in the prevention of udder infections. VI. Comparative efficacy of a teat dip under experimental and natural exposure to mastitis pathogens.

Efficacies (reduction of new intramammary infections) of a bronopol teat dip under experimental exposure to Streptococcus agalactiae and Staphylococcus aureus were 41.7 and 54.4%. Under natural exposure, efficacy was 35.0% (P greater than .05) against Streptococcus species and 50.0% against Staphylococcus aureus during the first 9 mo of a 12-mo trial when favorable milking equipment and labor conditions prevailed. Corresponding figures were 20.0 and 13.0% during the last 3 mo following onset of malfunctioning equipment and deterioration of labor services.