title: Pathogen-specific incidence rate of clinical mastitis in Flemish dairy herds, severity, and association with herd hygiene.
abstract: A one-year survey on clinical mastitis was conducted on 50 randomly selected commercial Flemish dairy herds to estimate the pathogen-specific incidence rate of clinical mastitis (IRCM). The severity of the cases and the potential associations with herd hygiene were studied. Participating producers sampled 845 cases and 692 dairy cows. The mean and median IRCM was estimated at 7.4 and 5.3 quarter cases per 10,000 cow-days at risk, respectively. A large between-herd variation was observed (range of 0-21.3). In general, the IRCM was lower in heifers compared with multiparous cows (2.9 vs. 11.0 quarter cases per 10,000 cow-days at risk). However, the overall IRCM in the first week after calving was higher in heifers compared with cows (43.4 vs. 31.6 quarter cases per 10,000 cow-days at risk). Streptococcus uberis (18.2% of the cases) and Escherichia coli (15.5%) were the most frequently isolated pathogens and no growth was observed in 19.9% of the cases. The majority of the cases (63.1%) were mild (only clots in milk). Moderate (hard quarter without general signs) and severe symptoms (systemic illness) were observed in 29.9 and 7.0% of the cases, respectively. Isolation of E. coli (vs. any other culture result) was more likely in moderate and severe cases compared with mild cases. Overall IRCM and E. coli IRCM were higher in dirty compared with clean herds based on udder hygiene scores (9.0 and 1.7 vs. 6.0 and 0.6 quarter cases per 10,000 cow-days at risk, respectively). This study broadens the knowledge on clinical mastitis in Flemish dairy herds and underlines the high risk of CM in early-lactation heifers, the role of the so-called environmental pathogens, and herd hygiene.
authors.affiliation: M-team and Mastitis and Milk Quality Research Unit, Department of Reproduction, Obstetrics, and Herd Health, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium. Electronic address: Joren.Verbeke@UGent.be.
authors.forename: Joren
authors.initials: J
authors.lastname: Verbeke
authors.affiliation: M-team and Mastitis and Milk Quality Research Unit, Department of Reproduction, Obstetrics, and Herd Health, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium.
authors.forename: Sofie
authors.initials: S
authors.lastname: Piepers
authors.affiliation: Milk Control Centre Flanders, 2500 Lier, Belgium.
authors.forename: Karlien
authors.initials: K
authors.lastname: Supré
authors.affiliation: M-team and Mastitis and Milk Quality Research Unit, Department of Reproduction, Obstetrics, and Herd Health, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium.
authors.forename: Sarne
authors.initials: S
authors.lastname: De Vliegher
mesh_terms: D000818:Animals; D001530:Belgium / Q000453:epidemiology; D002417:Cattle; D003612:Dairying; D004926:Escherichia coli / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D005260:Female; D006920:Hygiene / Q000592:standards*; D015994:Incidence; D007774:Lactation; D008414:Mastitis, Bovine / Q000453:epidemiology* / Q000382:microbiology*; D012621:Seasons; D012720:Severity of Illness Index; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D013291:Streptococcus / Q000302:isolation & purification
keywords: clinical mastitis; herd hygiene; incidence rate; severity