Research progress on mental health traits of pigs

With the development of large-scale and intensive pig farming, production management models such as weaning, mixing groups, and restrictive barriers have induced fear, anxiety, depression, and other stress responses in pig herds, significantly impacting production efficiency. Therefore, studying the genetic basis of pig mental health traits and conducting genetic improvement have significant implications for enhancing the production efficiency and economic benefits of the pig farming industry. This paper focused primarily on three aspects: stress responses and behavioral manifestations of pigs, exploration of the genetic basis of pig mental health traits, and the role of pigs as model animals for mental health research in medicine. This review summarized the potential stress responses and behavioral issues that may arise in pigs under intensive production management, evaluated indicators and methods for assessing pig mental health, and discussed genes reported to be associated with pig behaviors and stress responses. The current understanding of the genetic basis of pig mental health traits remains limited and requires further in-depth research for advancements in this field. Moreover, pigs as model animals hold significant potential for research into mental illnesses. In the future, leveraging pigs as a model system can facilitate a deeper exploration on the pathogenesis and treatment methods of human mental disorders.