Determination of teat dip germicidal activity using the excised teat model

Area of Science:

• Veterinary Microbiology
• Antimicrobial Efficacy Testing
• Dairy Cattle Health

Background:

• Postmilking teat antisepsis is vital for preventing bovine mastitis.
• Staphylococcus aureus and Streptococcus agalactiae are key mastitis pathogens.
• Evaluating antiseptic efficacy is crucial for effective mastitis control strategies.

Purpose of the Study:

• To assess the antimicrobial efficacy of fifteen postmilking teat antiseptics.
• To compare the effectiveness of different antiseptic formulations against major mastitis pathogens.
• To determine the impact of storage on antiseptic activity.

Main Methods:

• Utilized the excised teat model for efficacy testing.
• Tested antiseptics against Staphylococcus aureus Newbould 305 and Streptococcus agalactiae Cornell 48.
• Evaluated products including iodophors, chlorhexidine, fermented milk detergents, and dodecylaminoalkyl glycine.

Main Results:

• Eight of nine iodophor products achieved >3 log reduction against both pathogens.
• A .5% chlorhexidine product showed variable efficacy (3.22 vs. 2.92 log reduction).
• Dodecylaminoalkyl glycine products demonstrated high efficacy (>3.5 log reduction for Staph. aureus, >4 for Strep. agalactiae).
• Fermented milk products retained efficacy after one year of storage.

Conclusions:

• Certain iodophor and dodecylaminoalkyl glycine formulations are highly effective postmilking teat antiseptics.
• Chlorhexidine efficacy may vary depending on the pathogen.
• Fermented milk-based detergents show promise with good stability.
• Effective teat antisepsis is critical for managing bovine mastitis.