Theme Optimization of immune resistance in cow-calf farms. Objectives Raise awareness among cow-calf farmers of the factors associated with good animal immunity. Promote the adoption of recommended practices that optimize animal immunity, including through the establishment of standardized procedures for vaccination and colostrum management. Document the practices of breeders in relation to animal immunity in order to monitor their temporal evolution and determine priorities for action. Contribute to enhancing the role of advisor to the veterinarian in the adoption of good practices related to the health of cow-calf farms.