Animal welfare has been conceptualized in such a way that the use of animals in science and for food seems justified. I argue that those who have done this have appropriated the concept of animal welfare, claiming to give a scientific account that is more objective than the “sentimental” account given by animal liberationists. This strategy seems to play a major role in supporting merely limited reform in the use of animals and seems to support the assumption that there are conditions under which animals may be raised and slaughtered for food that are ethically acceptable. Reformists do not need to make this assumption, but they tend to conceptualize animal welfare is such a way that death does not count as harmful to the interests of animals, nor prolonged life a benefit. In addition to this prudential value assumption, some members of this community have developed strategies for defending suitably reformed farming practices as ethical even granting that death and some other forms of constraints are harms. One such strategy is the fiction of a domestic contract. However, if one accepts the conceptualization of human welfare give by L. W. Sumner, and applies it to animals in the way that I think is justified, an accurate conceptualization of animal welfare has different implications for which uses of animals should be regarded as ethically acceptable. In this paper I give an historical and philosophical account of animal welfare conceptulization and use this account to argue that animal breeders, as custodians of the animals they breed, have the ethical responsibility to help their animal wards achieve as much autonomy as possible in choosing the form of life made available to them and to provide that life. Attempts to avoid these implications by alluding to a contract model of the relationship between custodians and their wards fail to relieve custodians of their ethical responsibilities of care.