Characterization of clinical mastitis occurring in cows on 50 large dairy herds in Wisconsin
Open Access
- 1 December 2013
- journal article
- Published by American Dairy Science Association in Journal of Dairy Science
- Vol. 96 (12), 7538-7549
- https://doi.org/10.3168/jds.2012-6078
Abstract
In recent years, the US dairy industry has experienced significant demographic changes, with an increase in the number of large herds. The objectives of the present study were to characterize clinical mastitis occurring in cows on large dairy herds in Wisconsin. Participating herds (n=50) were required to have a minimum of 200 lactating animals, participate in monthly DHI testing (including monthly individual cow somatic cell count), use computerized herd records, use a milking routine that included fore-stripping quarters for detection of mastitis, and use antimicrobials to treat affected cows. After study personnel visited the farm, each herd was instructed to enroll the next 17 cows that experienced clinical mastitis, regardless of severity. At detection of clinical mastitis and 14 to 21 d after treatment ended, duplicate quarter milk samples were collected from all affected quarters and used for microbiological analysis. Treatments of affected cows were performed according to existing individual farm protocols. Cow level follow-up data was collected for 90 d after enrollment. Microbiological diagnoses at enrollment included gram-negative (35.6%), no growth (27.3%), gram-positive (27.5%), and other (9.6%). Of the 741 cases, the most prevalent pathogens were Escherichia coli (22.5%), followed by environmental streptococci (12.8%), Klebsiella spp. (6.9%), and coagulase-negative staphylococci (6.1%). Bacteriological cure was 75.0% for cases caused by gram-negative pathogens (n=136), 50.8% for cases caused by gram-positive pathogens (n=128), 47.5% for cases caused by other pathogens (n=40), and 73.2% for cases which did not result in microbial growth (n=123). Of the 583 cases with severity recorded, the distribution of mild, moderate, and severe symptoms was 47.8, 36.9, and 15.3%, respectively. The majority of cases presenting with severe symptoms were caused by gram-negative pathogens. Treatment cure was greater for gram-negative pathogens and cases for which no pathogens were recovered as compared with cases caused by other etiologies. Cows experiencing severe cases were more likely to receive multiple antimicrobial treatments.Keywords
This publication has 37 references indexed in Scilit:
- Microbial aetiology of acute clinical mastitis and agent-specific risk factorsVeterinary Microbiology, 2009
- Factors affecting cure when treating bovine clinical mastitis with cephalosporin-based intramammary preparationsJournal of Dairy Science, 2009
- Effect of pathogen-specific clinical mastitis on herd life in two New York State dairy herdsPreventive Veterinary Medicine, 2005
- Effect of Pathogen-Specific Clinical Mastitis on Milk Yield in Dairy CowsJournal of Dairy Science, 2004
- Severity of E. coli mastitis is mainly determined by cow factorsVeterinary Research, 2003
- Efficacy of Systemic Ceftiofur as a Therapy for Severe Clinical Mastitis in Dairy CattleJournal of Dairy Science, 2002
- Management Practices Associated with the Incidence Rate of Clinical MastitisJournal of Dairy Science, 1999
- Characterization of Staphylococcus simulans strains isolated from cases of bovine mastitisVeterinary Microbiology, 1999
- Incidence of Clinical Mastitis in Dairy Herds Grouped in Three Categories by Bulk Milk Somatic Cell CountsJournal of Dairy Science, 1998
- Efficacy of Intramammary Antibiotic Therapy for Treatment of Clinical Mastitis Caused by Environmental PathogensJournal of Dairy Science, 1993