Weaning dairy calves : management and performance on commercial farms

Dairy cattle undergo early life experiences in calfhood that can affect their welfare. One of these early life experiences is weaning, the transition from milk to solid feed. Little is understood about how these practices are implemented on commercial farms and how calves are performing through weaning under these diverse settings. The aim of my thesis was to describe current calf rearing practices, weaning performance, and farmer experiences weaning calves on commercial dairy farms in the Fraser Valley region of British Columbia, Canada. In Chapter 1, I review the existing literature on calf rearing around the time of weaning, along with describing calf care and management on dairy farms in North America. This chapter also includes an introduction to social science concepts that have been utilized in animal welfare research. Chapter 2 reports a survey study conducted across British Columbia, Canada that aimed to describe calf rearing practices and the methods used to monitor growth. I found that the farms surveyed offer higher than previously reported milk allowances (>8 L/d), primarily housed calves individually, and visually assessed calf growth. In Chapters 3 and 4, I conducted a yearlong study that explored weaning performance on 13 commercial dairy farms through both quantitative and qualitative methods. Chapter 3 provides a quantitative description of calf growth from birth through weaning, including differences between pre-and post-weaning growth. On the farms included in this study (n=12), calves generally continued to grow well through weaning, but 43% of calves experienced a decrease in growth during this period. Chapter 4 shares farmers’ experiences in participating in a longitudinal study and receiving benchmark reports through repeated interviews. I found that for some farmers, receiving benchmarking reports helped motivate changes that improved calf outcomes. In summary, the results from my thesis provide insight into calf rearing practices, calf growth, and farmer experiences through weaning on commercial dairy farms in British Columbia. Using a mixed-methods approach, I examined both the calf management practices and growth rates occurring on farms, as well as the factors influencing farmers’ decision-making; this approach provided a comprehensive understanding of weaning on commercial dairy farms.