Evaluation of ultrasonography for measuring solar soft tissue thickness as a predictor of sole ulcer formation in Holstein-Friesian dairy cows

Abstract

The aim of this research was to investigate the correlation between the thickness of solar soft tissue (SST; i.e. the corium and subcutaneous tissue) in early lactation and sole ulcer formation in late lactation. Fifty Holstein-Friesian cows were examined three times: (1) 30. days after calving (locomotion scoring, trimming, claw examination, measurement of SST); (2) 70. days after calving (locomotion scoring); and (3) 180. days after calving (locomotion scoring, trimming, claw examination).SST thickness was measured using an 8. MHz linear probe, at two points (SST1 below the apex of the pedal bone, and SST2 below the flexor tubercle). Mean values for SST1 and SST2 were 3.26. ±. 0.43. mm and 4.35. ±. 0.46. mm, respectively; the two measures were positively correlated (r= 0.95, P<. 0.001). At 180. days after calving, a sole ulcer was diagnosed in 12/50 cows (24%). Cows with a thinner SST had a higher risk of developing sole ulcers than those with a thicker SST. The optimal cut-off values of SST1 and SST2 in predicting cows with sole ulcers (as calculated by ROC analysis) was ≤3. mm for SST1 and ≤3.9. mm for SST2. The relative risk of a sole ulcer developing, based on those cut-off values was 4.25 (95 CI, 1.77-24.88) for SST1. ≤. 3. mm and 3.63 (95 CI, 1.18-10.8) for SST2. ≤. 3.9. mm. © 2013 Elsevier Ltd.