Cow's health and farmer's attitude towards the culling decision in dairy herds

<p>The study described in this thesis focusses on the health related culling decision in dairy cows, with special attention to the role of farmer's attitude in this process. This thesis is composed of four parts. In the first part, the associations between diseases and culling in dairy cows were reviewed and discussed from the literature. In the second part, the impact of disease on longevity was assessed in terms of risk of culling and in terms of reduced length of productive life. The third part focussed on methodological issues, and proposed a method accounting for within-cow-dependency of lactations to assess diseases as risk factors for culling. The differences between farmers in their culling decision process were specifically studied in the fourth part through the assessment of the associations between farmers' culling decisions and management styles. Applications of the present study and perspectives in the field of herd health management were discussed