Steps towards understanding the consistently high prevalence of lameness and hock injuries on Canadian dairy farms
This thesis was an exploration of the current lameness prevalence and hock injury prevalence in Canada, and an examination of potential communication barriers for farmers regarding discussion on such topics as lameness and hock injuries on farm. A training method for animal-based measures in welfare assessments in dairy cattle was created and validated to ensure high repeatability in assessors recording animal-based measures. A cross-sectional study was implemented to gather data on management practices surrounding welfare issues and current prevalence of hock injuries and lameness, as well as explore potential risk factors for those welfare issues. Lastly, a qualitative study was conducted to explore dairy farmers’ expectations of and receptivity to being approached and receiving advice on animal welfare issues. The training methodology and validation of the training showed that assessors can achieve high repeatability and accuracy for reporting on animal-based measures including: body condition, hock injuries, lameness, and cleanliness, which aid in monitoring these important indicators for welfare. A cross-sectional survey and follow-up farm evaluated management practices that may contribute to reduced lameness and hock injuries on farm. Most farmers never look for lameness aside from casual observation when milking. The hock injury and lameness prevalence estimates were 32% and 29% respectively. The prevalence of lameness was associated with geographical region, barn types (i.e. freestall), depth of bedding, time to investigation of a mildly lame cow and the prevalence of dirty udders and flanks. Ninety percent of farmers believe their herd’s resting surface minimizes hock injuries and provides comfort, however, the majority of farms use mattresses and mats which are associated with higher levels of hock injuries. Hock injuries were reduced with access to pasture. The qualitative study highlighted that it is important to farmers that trusted consultants (i.e. veterinarians) provide insight into welfare issues on their farm by identifying welfare issues, broaching the subjected tactfully, and providing animal care services aimed at reducing welfare issues. Farmers felt this was important, as they can become "barn blind", meaning there can be a lack of perception of problems in one’s own barn.