Pigs as model species to investigate effects of early life events on later behavioral and neurological functions

Pigs are increasingly used as animal models of early life events, both as models for humans and as models for pigs in farming. The relative similarities of young pigs to young humans in terms of brain development, physiology, diet, and gastrointestinal function make pigs a potentially powerful animal model for human neonates. In farm-kept animals, effects of management practices in early life that may affect the welfare state of the animal throughout its life are underinvestigated. Tools for testing young pigs for cognitive development include operant tests, such as the holeboard, judgement bias, discrimination, and gambling tasks. Neurological testing may prove to be extremely valuable for evaluating development in pigs. All of these tests are in varying stages of validation; concerted efforts by those involved in pig research should be undertaken to validate and use validated tests in pigs. The specific welfare issues surrounding the use of pigs as model animals are discussed.