Thesis
Mastitis pathogen reduction with commercial teat disinfectants utilizing the excised teat model: examination of pre- and post-dips
Washington State University
Master of Science (MS), Washington State University
2014
Handle:
https://hdl.handle.net/2376/100639
Abstract
Use of both pre- and postmilking teat disinfectants is a common practice used to control mastitis. A disinfectant's efficacy in reducing pathogen load on teat skin is influenced by factors including the active ingredient, concentration, product formulation, duration of disinfectant contact time, and the species of bacteria. Two studies were conducted to examine the various effects of pre- and postmilking disinfectants (teat dips) using the excised teat model, an in vitro test where teats are removed from the mammary gland at slaughter and used to test the efficacy of disinfectants in the laboratory. The objective of Study 1 was to describe bacterial strain differences in sensitivity to four commercially available dips: Dip A--1% H2O2; Dip B--1% chlorine dioxide; Dip C--1% iodophor; and Dip D--0.5% iodophor. Eleven common mastitis pathogens, four strains per pathogen, were tested. The objective of Study 2 was to determine the percentage reduction of mastitis pathogens (n=8) with three commercially available premilking dips: Dip A; Dip D; and Dip E--0.25% iodophor, using contact times of 15, 30, and 45 seconds. Significant differences were detected between bacterial strains within pathogen species: Staphylococcus aureus, Staphylococcus chromogenes, and Streptococcus uberis, in the percentage of bacteria reduced on teat skin (P < 0.05). Mycoplasma bovis (97.9% log reduction) iv was the most sensitive to teat disinfectants and Staphylococcus haemolyticus (71.4% log reduction) was the most resistant. Study 2 revealed that contact times of 30, and 45 seconds were equally effective (P > 0.05) in reducing recovered bacteria and were significantly more effective when compared to a contact time of 15 seconds with Dips D and E (P < 0.05). All contact times appeared to equally reduce bacterial numbers after application of Dip A (P > 0.05). In conclusion, there was variation in the sensitivity of bacterial species and strains; furthermore, a contact time of 30 seconds appeared to be optimum for reducing bacteria on teat skin.
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Details
- Title
- Mastitis pathogen reduction with commercial teat disinfectants utilizing the excised teat model
- Creators
- Benjamin David Enger
- Contributors
- Lawrence K. Fox (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Animal Sciences, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525168701842
- Language
- English
- Resource Type
- Thesis