title: Association between management practices and within-herd prevalence of Cryptosporidium parvum shedding on dairy farms in southern Ontario.
abstract: To identify management practices associated with an increased within-herd prevalence of Cryptosporidium parvum shedding on dairy farms in southern Ontario, fecal samples were taken from 1089 calves aged 7-28 days, from 119 herds. Information on management practices was obtained by administering a questionnaire compiled using a modified Delphi technique. Data were analyzed using univariable and multivariable negative binomial regression. Overall, 30% of the calves in the study were shedding C. parvum oocysts, with at least one positive calf detected in 77% of herds. Within-herd prevalence ranged from 0 to 80%. Predictors significantly associated with an increased prevalence of shedding in multivariable modelling were the use of calf scour prophylaxis in cows (risk ratio [RR] 1.70, P<0.01) and calves (RR 1.38, P=0.02) and the feeding of milk replacer in the first week of life (RR 1.40, P=0.02). In contrast, the presence of concrete flooring in calf housing areas (RR 0.59, P<0.01) and the use of soap or detergent when washing calf feeding utensils (RR 0.61, P<0.01) appeared to be protective.
authors.affiliation: Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1, Canada. ltrotzwi@uoguelph.ca
authors.forename: Lise A
authors.initials: LA
authors.lastname: Trotz-Williams
authors.forename: S Wayne
authors.initials: SW
authors.lastname: Martin
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Leslie
authors.forename: Todd
authors.initials: T
authors.lastname: Duffield
authors.forename: Daryl V
authors.initials: DV
authors.lastname: Nydam
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Peregrine
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D000831:Animals, Newborn; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D003457:Cryptosporidiosis / Q000453:epidemiology / Q000662:veterinary*; D016785:Cryptosporidium parvum / Q000302:isolation & purification*; D003612:Dairying; D005243:Feces / Q000469:parasitology; D005260:Female; D009864:Ontario / Q000453:epidemiology; D015995:Prevalence; D011795:Surveys and Questionnaires