A history of lameness and low body condition score is associated with reduced digital cushion volume, measured by magnetic resonance imaging, in dairy cattle

Objectives

The current study was designed to investigate associations between animal level variables (including lameness history) and the volume of, and fat content within, the digital cushion in adult dairy cattle at cull. The null hypothesis was that the digital cushion volume within the hindfeet of dairy cows at cull was not associated with claw horn lesion (CHL) or a history of lameness during the lactating lifetime of the animal. The secondary objective of the study was to quantify the volume and fat fraction of the digital cushion in a sample of culled dairy cows.

Materials and methods

The retrospective cohort study resulted in the scanning of 102 pairs of hindfeet, collected from adult Holstein dairy cows culled from a research herd, using a 3-Tesla, research grade MRI scanner. Volume and fat measurements were calculated for each digital cushion within each claw from a modified DIXON quant sequence. Animal level variables were constructed around the animal’s lactating lifetime, with lameness scores and body condition score (BCS) collected at least fortnightly. The combined volume of digital cushion in the lateral claws was used as the outcome variable in multivariable linear models. [...]