This study brings together information from four independent datasets to characterize the epidemiology of humeral fractures in New Zealand dairy cattle and to estimate how often these injuries occur at both herd and animal levels from 2007 to 2015. The first source was a national case collection reported by veterinarians over five lactation seasons (2007/2008–2011/2012). The second included post-slaughter findings from a Waikato pet food company that documented fractured humeri in casualty cows during the 2014/2015 season. The third dataset came from a veterinary practice in the same region that recorded its own fracture cases for that season. The fourth involved a nationwide phone survey of 505 randomly selected dairy farmers, who reported instances of severe, non–weight-bearing forelimb lameness in first- and second-lactation cows during 2014/2015. These survey responses were used to estimate within-herd and herd-level incidence. Across the national veterinary reports, 149 fracture cases were identified in 22 herds; the pet food dataset documented 61 cases on 41 farms; and the veterinary practice recorded 14 cases on 10 farms. All cases involved first- or second-lactation cows, with the highest frequency occurring between calving and early mating. According to the national survey, 11.7% of herds had at least one cow requiring euthanasia for severe forelimb lameness, with affected herds showing an average incidence of 2.6% in first-lactation cows and 2.8% in second-lactation cows. Overall, the combined evidence indicates that these fractures are more common than previously recognized and that they may recur across years in some herds. Additional research is needed to identify feasible management strategies to lessen both animal suffering and production losses.
