The aim of this article is to contribute detailed ethnographic material to broaden the scope of what we mean by reproductive technology. Technology can be defined not only by a series of laboratory techniques that are drafted into the daily management of the animal body, but also by a range of on-farm management strategies and working routines, as well as the cultural dispositions, social networks and tacit knowledge of the actors involved. RT is communicated to lay operators and disseminated amongst (...) semi-professional figures such as breed experts, herd inspectors and technical consultants. The practical contexts in which reproductive knowledge is popularized and applied provide ample scope for local negotiations, resistance and conflict. Professional knowledge about breed-improvement is personalised and appropriated by operators and plays a role in power relations and the exercise of personal charisma as well as being specific to context, in particular the nuances of pre-existing relationships of trust, friendship, kinship or hierarchy. No wonder then that many ambivalences and compromises coexist in the practice of applying ‘reproductive knowledge’ to breed selection. (shrink)