The effect of non-steroidal anti-inflammatory drugs, therapeutic hoof trimming and orthopedic block application on lameness in multiparous dairy cattle, a randomized controlled trial

Hoof horn lesions are recurrent in nature and cause long-term pathological challenges to the functional anatomy of the hoof in dairy cattle. It is hypothesized that inflammation is a driver of these pathological changes. It has previously been identified that routine treatment at first and subsequent calving and lameness events with non-steroidal anti-inflammatory drugs (NSAIDs) was important in reducing the future risk of lameness in dairy heifers. The impact NSAID administration has on lameness outcomes for multiparous dairy cattle is unknown. We conducted a 34mo randomized controlled trial to investigate the effects of routine administration of the NSAID ketoprofen during treatment for lameness and at calving, on the future probability of lameness and culling, caused by exposure to normal farm conditions. Dairy cattle that had calved at least once were recruited from a single herd, and randomly allocated to one of 4 treatments while controlling for parity, proportion of occasions scored as lame 8wks before study onset, and days in milk. All lactating animals were lameness scored every 2wk, to identify lame animals requiring treatment. Animals in Group 1 received a therapeutic trim and an orthopedic hoof block (if deemed necessary) every time they were treated for lameness. Animals in Group 2 received a 3-d course of ketoprofen (single dose daily), alongside the same treatment as Group 1 every time they were treated for lameness. Animals in Group 3 received a 3-d course of ketoprofen (single dose daily) starting 24 to 36 h after each calving, alongside the same treatment as Group 2 for lameness. Animals in Group 4 received a 3-d course of ketoprofen (single dose daily) every time they were identified with lameness, with no therapeutic trim, unless they were identified as severely lame (a single score ≥ 3a). Animals were followed for the 34mo duration of the study. Independent lameness outcome scores were collected every 2wks by technicians who were blinded to Treatment Group to assess the probability of lameness. Culling data were extracted from farm records. A total of 425 animals were recruited to the study (105 in Group 1, 107 in Group 2, 107 in Group 3 and 106 in Group 4), with data from 412 animals included in the final analysis (n = 102 Group 1, 102 Group 2, 106 Group 3, and 102 Group 4). The effect of Treatment Group on the ongoing probability of lameness was evaluated through the use of mixed effect, logistic regression models. Compared with anim