Digital Cushion Depth Affects Susceptibility to Claw Horn Lesions

By Steve Mason on

A study by researchers at Cornell University examined the association between claw horn lesions and the depth of the digital cushion evaluated by ultrasound examination of the sole at the typical sole ulcer site.

Ultrasound measurement of digital cushion depthAnatomy of Digital Cushion

Prevalences of claw horn lesions in the 192 first lactation and 309 second-plus lactation cows observed in the study are recorded in the table below.

Lesion% of First Lactation
Cows with Lesions
% of Second+ Lactation
Cows with Lesions
Sole Ulcer4.227.8
White Line Lesion1.06.5
Toe Necrosis0.51.9

The prevalence of sole ulcers and white line lesions was significantly associated with thickness of the digital cushion; cows in the upper quartile of digital cushion thickness had an adjusted prevalence of lameness that was 15 percentage points lower than the lower quartile (24.4% versus 8.6% prevalence). Body condition scores were positively associated with digital cushion thickness.

As illustrated in the graph below, digital cushion thickness decreased steadily from the first month of lactation and reached a nadir 120 days after parturition, matching the typical pattern seen for body condition scores. These results give support to the concept that sole ulcers and white line lesions are related to contusions within the claw horn capsule which are a consequence of the lower capacity of the digital cushion to dampen the pressure exerted by the third phalanx (pedal bone) on the soft tissue beneath.

Changes in digital cushion depth during the lactation cycle

Changes in digital cushion depth during the lactation cycle

source: R.C. Bicalho, V. S. Machado and L.S. Caixeta, Journal of Dairy Science 92:3175 (2009) – full article here.

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