Validation of Standing and Locomotion Scoring, Behavioral Assessments, and Mechanical Nociceptive Threshold Testing on Naturally Occurring Sow Lameness

SIMPLE SUMMARY: One of the most common reasons that sows are removed from a farm when they would otherwise still be productive is from lameness. The causes of lameness are highly varied and could involve multiple body systems. Early detection, before the problem is untreatable, improves success. Several technologies have been developed to detect lameness earlier when it is less obvious; however, there has been limited testing of them on naturally occurring causes of lameness in sows. This study enrolled animals from a typical farm, moved them to an intensive study lab, and applied these tests to see if they were capable of accurately identifying a variety of naturally occurring lameness problems. Standing and moving lameness scoring, withdrawal from the application of pressure to the leg, the number of pig–human interventions needed to keep animals moving through an obstacle course, and the time to complete an obstacle course were evaluated. Standing and locomotion lameness scoring systems, mechanical pressure, and pig behavior could discriminate between animals with mild organic lameness and animals that were sound and may have utility on the farm and could be used by staff to identify and manage lame animals. In rare instances, the tools used here were able to discriminate between broad categories of lameness causes. ABSTRACT: The objective of this study was to validate standing and locomotion lameness scoring, mechanical nociceptive threshold testing, and behavioral profile tools for the diagnosis of naturally occurring lameness etiologies in pigs. A total of 55 crossbred gilts and sows obtained from a commercial farm were enrolled in the study; with sound pigs classified as controls (8) and the remainder as lame due to integumentary (20), musculoskeletal (15), and combinations of integumentary and musculoskeletal (12) etiologies. Standing and locomotion lameness, mechanical nociceptive threshold (MNT) test, pig-human interventions, and latency to complete an obstacle course were evaluated. Standing and locomotion lameness scoring systems, MNT, and pig behavior (latency) were capable of discriminating between animals with mild organic lameness and animals that were sound and may have utility on the farm for staff to use to identify and manage lame animals. In rare instances, the tools used here were able to discriminate between broad categories of lameness etiology.