Why using genetics to address welfare may not be a good idea.

Welfare of animals in livestock production systems is now widely defined in terms of 3 classes of measures: veterinary health, mental well-being (or feelings), and natural behaviors. Several well-documented points of tension exist among welfare indicators in these 3 classes. Strategies that aim to improve welfare using genetics can increase resistance to disease and may also be able to relieve stress or injury. One strategy is to reduce the genetic proclivity of the bird to engage in behaviors that are frustrated in modern production systems. Another is to develop strains less prone to behaviors hurtful to other hens. Yet another is to make overall temperament a goal for genetic adjustments. These genetic approaches may score well in terms of veterinary and psychological well-being. Yet they also involve changes in behavioral repertoire and tendencies of the resulting bird. Although it has seemed reasonable to argue that such animals are better off than frustrated or injured animals reflecting more species-typical behaviors, there is a point of view that holds that modification of a species-typical trait is ipso facto a decline in the well-being of the animal. Additionally, a significant amount of anecdotal evidence has been accumulated that suggests that many animal advocates and members of the public find manipulation of genetics to be an ethically unacceptable approach to animal welfare, especially when modifications in the environment could also be a response to welfare problems. Hence, though promising from one perspective, genetic strategies to improve welfare may not be acceptable to the public.