Evaluation of biomechanical strength and strain of bovine hoof lamina in elevated mobility score market weight cattle

Objective

Impaired mobility of cattle arriving at packing plants gained considerable attention in the fall of 2013. In addition to a stiff gait and reluctance to move, cattle presented with increased respiratory rates and muscle tremors. In the most severe cases, animals were observed to slough one or more hooves (claw horn capsules) during transport or while in lairage. Affected animals experienced significant discomfort and when hoof sloughing occurred at the packing plant, these animals were unable to be processed creating both an animal welfare issue as well an economic loss to the packer. It is believed that a better understanding of possible molecular causes of this condition would help feeders develop better feeding and management practices to prevent the disease. This report describes experimental evaluation of the relationship between the mobility of market weight cattle and the biomechanical properties of the laminar corium.

Materials and methods

Eighty-six market weight cattle were evaluated at a commercial slaughter facility. Mobility scores, as described by the North American Meat Institute, were assigned by trained company employees. Animals were observed and scored during antemortem exam and subsequently marked using a color code for each score. All animals with indications of disease or blindness were excluded. Following slaughter, both front hooves were collected within the packing plant and frozen for transportation to the research facility. Using a randomization chart, left or right hooves were selected and biomechanically tested using a test frame to determine the force required to remove the hoof horn from the pedal bone. The test results were compared based on ante-mortem locomotion score. [...]