title: Handheld mechanical nociceptive threshold testing in dairy cows - intra-individual variation, inter-observer agreement and variation over time.
abstract: OBJECTIVE
  To examine the use of handheld methodology to assess mechanical nociceptive threshold (MNT) on cows kept loose-housed.
  
  
  METHODS
  Prospective randomized partial cross-over experimental study. A one-factor (test day) design was used to evaluate MNT over time.
  
  
  METHODS
  One hundred and fifteen healthy, loose-housed Danish Holstein cattle.
  
  
  METHODS
  We evaluated intra-individual variation, inter-observer agreement and variation over time of MNT using two handheld devices and two stimulation sites. Mechanical, ramped stimulations were performed with an algometer (6.5 mm diameter steel probe, 0-10.0 kgf) or an electronic von Frey device (plastic tip with diameter 0.8 mm, 0-1000 gf). Each cow received 5-6 consecutive stimulations within a 2 × 5 cm skin area on the dorsal or lateral aspect of the left third metatarsus until an avoidance reaction occurred. We investigated the difference in precision [expressed as coefficient of variation (CV)] between the combinations of devices and stimulation sites. The inter-observer agreement and the difference in MNT between test day 1, 3, 7, 10 and 24 were investigated for selected combinations. Data were analysed in mixed models and Bland-Altman as relevant.
  
  
  RESULTS
  The CVs did not differ [range 0.34-0.52 (p = 0.1)]. Difference between observers (95% limits) was 0.2 kgf (2.8) and 4 gf (369) for the algometer and von Frey device, respectively. Mechanical nociceptive threshold increased from 361 on test day one to 495 gf on test day 24 (p < 0.01).
  
  
  CONCLUSIONS
  All methods showed a high degree of intra-individual variation, and no combination of device and stimulation site showed superior precision. Mean difference between observers was low, and MNT was not consistent over time. Further development of the methods is required before they can be used in research to investigate possible relations between claw lesions and hyperalgesia.
authors.affiliation: Knowledge Centre for Agriculture, Cattle, Aarhus N, Denmark.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Raundal
authors.forename: Pia H
authors.initials: PH
authors.lastname: Andersen
authors.forename: Nils
authors.initials: N
authors.lastname: Toft
authors.forename: Björn
authors.initials: B
authors.lastname: Forkman
authors.forename: Lene
authors.initials: L
authors.lastname: Munksgaard
authors.forename: Mette S
authors.initials: MS
authors.lastname: Herskin
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis; D018592:Cross-Over Studies; D005260:Female; D059225:Nociception; D059226:Nociceptive Pain / Q000175:diagnosis / Q000662:veterinary*; D015588:Observer Variation; D010147:Pain Measurement / Q000379:methods / Q000662:veterinary*; D017288:Pain Threshold
keywords: dairy cows; mechanical nociceptive threshold; pain
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