Research progress on animal environment and welfare

Animal welfare closely depends on its ability to adapt and thrive in a harmonious relationship with its environment, ensuring both physical and psychological well-being. Over the years, the welfare of farm animals has gathered global attention and has become increasingly important to the general public and scientific communities. The connection between the environment and animal welfare is primarily established through the provision of suitable and controllable environment for animals. However, it is essential to recognize that the impact of environment extends beyond merely ensuring freedom from discomfort. The environment plays a crucial role in shaping an animal's response to challenges such as disease, stress, and pathogen. While animals may be housed in controlled environments that provide optimal conditions for health, production, and welfare, it is important to acknowledge that specific scenarios can significantly affect and alter the environmental requirements. Even with access to fresh air, certain factors can have a substantial impact on the well-being of animals. Furthermore, providing appropriate environmental conditions goes beyond meeting basic needs and can greatly contribute to allowing animals to engage in their natural behaviors. It serves as a relevant tool for ensuring and maintaining adequate welfare standards. This review takes a comprehensive approach to environmental welfare by considering the welfare of animals managed in different stocking systems, considering environmental stress, stocking systems, and the provision of environmental enrichment items. By examining these factors, a broader understanding of the relationship between environment and welfare is achieved and recommendations for future research are outlined.