In THE FACULTY OF GRADUATE STUDIES

ii Hoof pathologies are a major concern in dairy production and lameness is considered to be one of the top three reasons for involuntary culling of lactating dairy cattle. The aim of this study was to determine the effect of a period of access to pasture before calving, versus continuous freestall housing, on the incidence of hoof lesions, dermatitis and heel erosion in dairy cattle during the months that follow calving. The hind hooves of all animals were scored for severe sole lesions, dermatitis and heel erosion pre-calving (200 to 0 days prior to calving), in early- lactation (0 to 100 DIM), and in mid- lactation (100 to 200 DIM). Over the course of the study, 42 out of 58 animals were diagnosed with severe lesions, 40 out of 58 animals were diagnosed with dermatitis, and 51 out of 58 animals were diagnosed with severe heel erosion. Multiparous cows were more affected by severe sole lesions than were primiparous animals during both the pre-calving (32 and 0 %, respectively) and mid- lactation periods (37 and 63 %, respectively). Cows housed continuously in freestalls tended to be more affected by dermatitis than were pastur