Any attempt to evaluate welfare, therefore, must take into account the scientific evidence available concerning the feelings of animals that can be derived from their structure and functions and also their behavior” (Duncan, 1981). The Brambell Committee’s report (1965) said, “Welfare is a wide term that embraces both the physical and mental well-being of the animal. In 1964, Ruth Harrison published her book Animal Machines, which produced such a stir in the UK that the Brambell Committee was formed to report on the state of animal welfare in the use of animals in the UK. Since the body of animal welfare science literature is extensive, I will select several reflective representatives of this movement for this examination of value assumptions. In Part II, I will focus on the emergence of the science of food animal welfare mandated by the Brambell Commission Report, the various conceptions of animal welfare developed or assumed by (food) animal welfare scientists and their co-philosophers, the accounts they give of their “value assumptions” and the ethical concerns to which they are related, and how these accounts function to justify what I call the on-going appropriation of the concept of animal welfare.