title: Influence of milking method, disinfection and herd management practices on bulk tank milk somatic cell counts in tropical dairy herds in Colombia.
abstract: The aims of this study were to evaluate the effects of milking method, disinfection practices and other management factors on the bulk tank milk somatic cell count (BTSCC) in tropical dairy herds and to examine potential interactions with time. One hundred and thirty farms in the Northern region of Antioquia, Colombia, were visited once per month for 24 months. A two level linear mixed model for repeated measures was used to assess the impact on log transformed BTSCC (lnBTSCC). The geometric mean of the BTSCC for all herds was 262,330 cells/mL. The two-level linear mixed model showed that lnBTSCCs in hand milked herds were significantly higher than in machine milked herds. Fore-stripping corresponded with a 27% increase in lnBTSCC and failing to post-dip corresponded with a 45% increase in lnBTSCC. The two way interactions of sampling month with milking method, singeing udders and pre-dipping were significant. The lowest predicted lnBTSCC was observed in machine milked herds that practised both pre-dipping and singeing of udders. This study suggests that milking procedures and disinfection practices can interact with time and have substantial effects on lnBTSCC.
authors.affiliation: Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P, Canada. Electronic address: jreyes@upei.ca.
authors.forename: J
authors.initials: J
authors.lastname: Reyes
authors.affiliation: Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Sanchez
authors.affiliation: Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Stryhn
authors.affiliation: Biogenesis Research Group, Faculty of Agricultural Sciences, University of Antioquia, Calle 70 No. 52-21, C.P. 050010 Medellin, Colombia.
authors.forename: T
authors.initials: T
authors.lastname: Ortiz
authors.affiliation: Biogenesis Research Group, Faculty of Agricultural Sciences, University of Antioquia, Calle 70 No. 52-21, C.P. 050010 Medellin, Colombia.
authors.forename: M
authors.initials: M
authors.lastname: Olivera
authors.affiliation: Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P, Canada.
authors.forename: G P
authors.initials: GP
authors.lastname: Keefe
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D002452:Cell Count / Q000662:veterinary; D003105:Colombia; D003612:Dairying / Q000379:methods*; D004203:Disinfection / Q000379:methods*; D005260:Female; D008892:Milk / Q000166:cytology*; D012621:Seasons
keywords: Bulk tank somatic cell count; Dairy cow; Intramammary infection; Milking method; Tropical