Behavioral responses of group-housed pigs are strongly influenced by pigsty environmental conditions, yet their dynamic coupling is difficult to quantify under commercial farming scenarios. This difficulty arises from high inter-pig similarity, complex interactions, and rapidly changing environmental conditions, which pose significant challenges for existing vision-based multi-pig behavior detection and tracking methods. To address these challenges, this study proposes a PIG-Net–based dynamic coupling analysis framework that integrates behavior detection, multi-pig tracking, and behavior-environment interaction analysis. The model uses an EfficientRepBiFusion backbone with bidirectional feature fusion and a lightweight LSDGCD detection head, achieving mean Average Precision (mAP) of 93.5% for PIG YOLO on four pig behaviors—standing, dog-sitting, lateral lying, and prone lying. The integrated PIG-Net system achieves stable tracking performance with identification average rate (IDF1) of 90.7%, multiple object tracking accuracy (MOTA) of 88.6%, and a real-time processing speed of 26 FPS, while environmental sensors continuously record temperature, humidity, and CO₂ levels for long-term correlation analysis. Based on long-term monitoring, Pearson correlation analysis was applied to quantify the associations between pig behaviors and environmental factors, highlighting significant correlations with coefficients |r| ranging from 0.65 to 0.76. By combining these quantitative results with temporal and dimensionality reduction analyses, temperature, humidity, and CO₂ were identified as the primary environmental drivers. Active behaviors decreased under elevated temperature and humidity and increased during cooler and drier periods, whereas prone lying and lateral lying increased under thermal and moisture stress. Elevated CO₂ concentrations further suppressed activity, reflecting inhibitory effects of degraded air quality. These findings provide a quantitative basis for behavior-environment coupling assessment and early health warning in group-housed pigs.

A large part of the world’s greenhouse gases comes from livestock and poultry breeding and manure. A survey report by the Food and Agriculture Organization of the United Nations（FAO） pointed out that animal husbandry is the industry that contributes the most to the greenhouse effect among all industries. Against the backdrop of the current goal of achieving“carbon peak and carbon neutrality”，in order to address the energy waste and environmental pollution caused by large-scale pig farms，building a multi energy complementary system for pig farms with clean energy as the main focus is of great significance in energy conservation，emission reduction，and improving energy efficiency. Inthelight of multi-energy complementation and energy cascade utilization，a multi-energy complementary system in pig farm has been constructed based on the pig farm’s own conditions that the pig farm has abundant biomass energy and solar energy，and it also has large daily electricity consumption and high heat load in winter. Based on the scale overview and load demand of the pig farm， appropriate supporting equipment was selected，the simulation calculation of photovoltaic power generation was conducted using PVsyst software. Taking into account the investment cost，equipment operation and maintenance cost，electric heating load demand，and seasonal demand of the system. Taking into account the system investment cost，equipment operation and maintenance cost，electric heating load demand，and seasonal demand，the final calculation showed that the pig farm can still earn 1.5857 million yuan based on the industry benchmark return rate of 8%，and the dynamic investment recovery period is approximately 7.3 years. Compared with traditional pig farms purchasing electricity from the grid，it can reduce carbon dioxide emissions by 204. 29 tons per year，indicating that the system can bring good economic benefits to pig farms and has significant energy-saving，emission reduction，and green environmental protection advantages. It can provide new business ideas for other farms such as chicken farms and cattle farms.