title: Effect of lameness on milk yield in dairy cows.
abstract: OBJECTIVE
  To examine the relationship between lameness and milk yield in dairy cows.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  531 dairy cows.
  
  
  METHODS
  Cows affected with lameness were classified into 1 of 3 groups on the basis of type of diseases or lesions observed, including interdigital phlegmon (foot rot), papillomatous digital dermatitis (foot warts), or claw lesions. Cows not affected with lameness were classified as healthy. From Dairy Herd Improvement Association records, 305-day mature equivalent milk yield data were collected at the end of lactation or when the cow left the herd. Milk yield was compared between cows affected with lameness and healthy cows.
  
  
  RESULTS
  167 (31%) cows were affected with lameness during lactation. Lame cows had claw lesions (60%), papillomatous digital dermatitis (31%), or interdigital phlegmon (9%). Milk yield in lame cows with interdigital phlegmon (mean, 17,122 lb) was significantly less, compared with healthy cows (19,007 lb).
  
  
  CONCLUSIONS
  In this herd, interdigital phlegmon was associated with a 10% decrease in milk production. Lame cows with claw lesions or papillomatous digital dermatitis produced less milk than healthy cows, but the difference was not significant.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610-0136, USA.
authors.forename: Jorge
authors.initials: J
authors.lastname: Hernandez
authors.forename: Jan K
authors.initials: JK
authors.lastname: Shearer
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Webb
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D005534:Foot Diseases / Q000503:physiopathology / Q000662:veterinary*; D006724:Hoof and Claw / Q000473:pathology; D007774:Lactation; D007794:Lameness, Animal / Q000503:physiopathology*; D008892:Milk / Q000378:metabolism*