title: Longitudinal study of the effects of teat condition on the risk of new intramammary infections in dairy cows.
abstract: Machine milking-induced alterations of teat tissue may impair local defense mechanisms and increase the risk of new intramammary infections. The objective of the current study was to assess the influence of short-term and long-term alterations of teat tissue and infectious status of the udder quarter on the risk of naturally occurring new intramammary infections, inflammatory responses, and mastitis. Short-term and long-term changes in teat condition of right udder quarters of 135 cows of a commercial dairy farm in Saxony-Anhalt, Germany, were recorded monthly for 10 mo using simple classification schemes. Quarter milk samples were collected from all examined quarters at each farm visit. Bacteriological culture results and somatic cell counts of quarter milk samples were used to determine new inflammatory responses (increase from ≤100,000 cells/mL to >100,000 cells/mL between 2 samples), new infections (detection of a pathogen from a quarter that was free of the same pathogen at the preceding sampling), and new mastitis (combination of new inflammatory response and new infection). Separate Poisson mixed models for new inflammatory responses, new infections, and new mastitis caused by specific pathogens or groups of pathogens (contagious, environmental, major, minor, or any) were used to estimate risk ratios and 95% confidence intervals. Data preparation and parameter estimation were performed using the open source statistical analysis software R. We observed no effect of any variable describing teat condition on the risk of new intramammary infections, inflammatory responses, or mastitis. Intramammary infections of the same udder quarter in the preceding month did not affect risk either.
authors.affiliation: Department of Bioprocess Engineering - Microbiology, Faculty II, University of Applied Science and Arts, Heisterbergallee 12, 30453 Hannover, Germany; Clinic of Animal Reproduction, Department of Veterinary Medicine, Freie Universität Berlin, Königsweg 65, 14163 Berlin, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Zoche-Golob
authors.affiliation: Department of Bioprocess Engineering - Microbiology, Faculty II, University of Applied Science and Arts, Heisterbergallee 12, 30453 Hannover, Germany; Clinic for Cattle, Stiftung Tierärztliche Hochschule Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Haverkamp
authors.affiliation: Department of Bioprocess Engineering - Microbiology, Faculty II, University of Applied Science and Arts, Heisterbergallee 12, 30453 Hannover, Germany.
authors.forename: J-H
authors.initials: JH
authors.lastname: Paduch
authors.affiliation: Department of Bioprocess Engineering - Microbiology, Faculty II, University of Applied Science and Arts, Heisterbergallee 12, 30453 Hannover, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Klocke
authors.affiliation: Department of Bioprocess Engineering - Microbiology, Faculty II, University of Applied Science and Arts, Heisterbergallee 12, 30453 Hannover, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Zinke
authors.affiliation: Clinic for Cattle, Stiftung Tierärztliche Hochschule Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Hoedemaker
authors.affiliation: Clinic of Animal Reproduction, Department of Veterinary Medicine, Freie Universität Berlin, Königsweg 65, 14163 Berlin, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Heuwieser
authors.affiliation: Department of Bioprocess Engineering - Microbiology, Faculty II, University of Applied Science and Arts, Heisterbergallee 12, 30453 Hannover, Germany. Electronic address: volker.kroemker@hs-hannover.de.
authors.forename: V
authors.initials: V
authors.lastname: Krömker
mesh_terms: D000818:Animals; D002417:Cattle; D003612:Dairying; D004487:Edema / Q000503:physiopathology / Q000662:veterinary*; D005260:Female; D005858:Germany; D008137:Longitudinal Studies; D008321:Mammary Glands, Animal / Q000382:microbiology / Q000503:physiopathology*; D008414:Mastitis, Bovine / Q000382:microbiology / Q000503:physiopathology*; D008892:Milk / Q000378:metabolism*; D012306:Risk
keywords: hyperkeratosis; mastitis; risk factor; teat edema; udder health