title: Effect of lameness on the calving-to-conception interval in dairy cows.
abstract: OBJECTIVE
  To examine the relationship between lameness and the duration of the interval from calving to subsequent conception in lactating dairy cows.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  837 dairy cows.
  
  
  METHODS
  Cows affected with lameness were classified into 1 of 4 groups on the basis of types of disease or lesions observed, including foot rot, papillomatous digital dermatitis, claw lesions, or multiple lesions. Cows not affected with lameness were classified as healthy. Time from calving to conception was compared between lame cows and healthy cows.
  
  
  RESULTS
  254 (30%) cows were affected with lameness during lactation. Most lame cows (59%) had claw lesions. Lame cows with claw lesions were 0.52 times as likely to conceive as healthy cows. Median time to conception was 40 days longer in lame cows with claw lesions, compared with healthy cows. Number of breedings per conception for lame cows with claw lesions was significantly higher than that for healthy cows.
  
  
  CONCLUSIONS
  Claw lesions were the most important cause of lameness, impairing reproductive performance in dairy cows, as indicated by a higher incidence of affected cows and a greater time from calving to conception and a higher number of breedings required per conception, compared with healthy cows.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610-0136, USA.
authors.forename: J
authors.initials: J
authors.lastname: Hernandez
authors.forename: J K
authors.initials: JK
authors.lastname: Shearer
authors.forename: D W
authors.initials: DW
authors.lastname: Webb
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D005298:Fertility; D005534:Foot Diseases / Q000503:physiopathology / Q000662:veterinary*; D006724:Hoof and Claw / Q000473:pathology; D007794:Lameness, Animal / Q000503:physiopathology*; D011247:Pregnancy; D013997:Time Factors