title: Monensin might protect Ontario, Canada dairy cows from paratuberculosis milk-ELISA positivity.
abstract: Our objective was to define the role of monensin sodium in protecting cows from being milk-ELISA positive for paratuberculosis in Ontario, Canada dairy herds. In total, 4933 dairy cows from 94 herds were enrolled in this cross-sectional study. Forty-four of the enrolled herds were selected purposively by their herd veterinarian and another 50 herds were randomly selected from a local milk production-recording agency. A herd-management survey was completed on each farm during the months of May through August 2003. During this same time-period, composite milk samples were collected from all lactating cows and tested with a milk-ELISA for antibodies to Mycobacterium avium subspecies paratuberculosis. Analyses were stratified according to the paratuberculosis history of the herds. In the 48 herds in which paratuberculosis had not been diagnosed before, the use of calf hutches and monensin in milking cows were both associated with reduced odds of a cow testing positive (OR=0.19 and 0.21, respectively). In the 46 herds with a prior history of paratuberculosis, feeding monensin to the breeding-age heifers was associated with decreased odds of a cow testing positive (OR=0.54). Monensin use might be associated with milk-ELISA positivity, but its impact on the transmission of paratuberculosis remains unknown.
authors.affiliation: Department of Large Animal Clinical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada. steve.hendrick@usask.ca
authors.forename: Steven H
authors.initials: SH
authors.lastname: Hendrick
authors.forename: Todd F
authors.initials: TF
authors.lastname: Duffield
authors.forename: Ken E
authors.initials: KE
authors.lastname: Leslie
authors.forename: Kerry D
authors.initials: KD
authors.lastname: Lissemore
authors.forename: Marie
authors.initials: M
authors.lastname: Archambault
authors.forename: Randy
authors.initials: R
authors.lastname: Bagg
authors.forename: Paul
authors.initials: P
authors.lastname: Dick
authors.forename: David F
authors.initials: DF
authors.lastname: Kelton
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis* / Q000187:drug effects; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000517:prevention & control / Q000635:transmission; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary; D005260:Female; D008892:Milk / Q000276:immunology* / Q000382:microbiology; D008985:Monensin / Q000494:pharmacology*; D016927:Mycobacterium avium subsp. paratuberculosis / Q000276:immunology*; D016017:Odds Ratio; D009864:Ontario; D010283:Paratuberculosis / Q000175:diagnosis* / Q000517:prevention & control / Q000635:transmission
chemical_list: D000907:Antibodies, Bacterial; D008985:Monensin