The French agricultural research institute INRA has developed experimental surgery in farm animals in the 1970s. The research programs are aimed at improving theroretical knowledge on major biological functions as well as practical applications on cattle, goats, sheep, pigs, and horses. In this article the research activity of the Reproductive Physiology and Behaviour centre is taken as an example because of its important experimental surgery unit specialized in abdominal and brain surgery. Surgical procedures are performed in a hospital and specimens are collected from a slaughterhouse. This research activity is very strictly controlled by the French regulation, and must be conducted in authorised premises by adequately trained personnel. Special care is given to the alleviation of post-surgical pain. In addition, scientists may seek the opinion of ethics committee on their experimental procedures.