Animal welfare--scientific approaches to the issues

Nonhuman animal welfare is of significant public interest, globally and within the United States. Value-based judgments are intrinsic to animal welfare assessment, according to the relative weighting of factors associated with animal performance, health, affective states, and natural living. The concept of animal welfare is consistent with the scientific method because questions are open to deductive reasoning, formation of hypotheses and predictions, and collection and analysis of empirical data. Multidisciplinary techniques used in the laboratory are helpful to understanding a whole animal response to particular situations and are especially important in interpretation of data about affective states. Epidemiological techniques can be used to identify prevalence and risk factors associated with particular animal welfare challenges in field conditions and are particularly useful for motivating change and evaluating the effectiveness of interventions intended to improve animal welfare on farms. Compromised animals who are affected by injury or illness represent a vulnerable population with unique animal welfare challenges for which laboratory and field-based studies are needed.