Abstract: A well-structured animal welfare system should ensure physiological health, environmental comfort, and adequate nutrition of pigs, allowing full expression of natural behaviors while maintaining freedom from negative psychological states such as pain, distress, and fear. More studies demonstrated that enhance welfare levels could significantly improve production efficiency and reproductive performance in swine, thereby increasing economic returns in the farming industry. However, intensive farming systems often created conflicts between production objectives and welfare requirements due to constraints in husbandry management and environmental conditions. This review elucidated the biological mechanisms through which animal welfare affects swine physiological functions, evaluated its economic implications for commercial operations, and specifically investigated the application potential of nutritional interventions, environmental enrichment strategies, and optimized husbandry practices in welfare enhancement. The findings provided theoretical foundations and practical frameworks for achieving sustainable development in intensive swine production systems.

Key words: pig welfare, influence mechanisms, nutritional regulation, environmental enrichment, husbandry management, improvement measures