title: Management practices associated with the rate of respiratory tract disease among preweaned beef calves in cow-calf operations in the United States.
abstract: OBJECTIVE
  To assess associations between herd management practices and herd-level rates of bovine respiratory disease complex (BRDC) in preweaned beef calves in US cow-calf operations.
  
  
  METHODS
  Cross-sectional survey.
  
  
  METHODS
  443 herds weighted to represent the US cow-calf population.
  
  
  METHODS
  Producers from 24 states were selected to participate in a 2-phase survey; 443 producers completed both survey phases and had calves born alive during the study period. Data from those respondents underwent multivariable negative binomial regression analyses.
  
  
  RESULTS
  Bred heifer importation was associated with lower BRDC rates (incidence rate ratio [IRR], 0.40; confidence interval [CI], 0.19 to 0.82), whereas weaned steer importation was associated with higher BRDC rates (IRR, 2.62; CI, 1.15 to 5.97). Compared with single-breed herds, operations with calves of 2-breed crosses (IRR, 2.36; CI, 1.30 to 4.29) or 3-breed crosses (IRR, 4.00; CI, 1.93 to 8.31) or composite-herd calves (IRR, 2.27; CI, 1.00 to 5.16) had higher BRDC rates. Operations classified as supplemental sources of income had lower BRDC rates (IRR, 0.48; CI, 0.26 to 0.87) than did operations classified as primary sources of income. Reported feed supplementation with antimicrobials was positively associated with BRDC rates (IRR, 3.46; CI, 1.39 to 8.60). The reported number of visits by outsiders in an average month also was significantly associated with herd-level BRDC rates, but the magnitude and direction of the effects varied.
  
  
  CONCLUSIONS
  Management practices associated with preweaning BRDC rates may be potential indicators or predictors of preweaning BRDC rates in cow-calf production systems.
authors.affiliation: Kansas State Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66502, USA.
authors.forename: Gregg A
authors.initials: GA
authors.lastname: Hanzlicek
authors.forename: David R
authors.initials: DR
authors.lastname: Renter
authors.forename: Brad J
authors.initials: BJ
authors.lastname: White
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Wagner
authors.forename: David A
authors.initials: DA
authors.lastname: Dargatz
authors.forename: Michael W
authors.initials: MW
authors.lastname: Sanderson
authors.forename: H Morgan
authors.initials: HM
authors.lastname: Scott
authors.forename: Robert E
authors.initials: RE
authors.lastname: Larson
mesh_terms: D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology*; D003132:Commerce; D003430:Cross-Sectional Studies; D005260:Female; D012140:Respiratory Tract Diseases / Q000473:pathology / Q000662:veterinary*; D014481:United States / Q000453:epidemiology