Increased Space Allowance Improves Productivity and Welfare in Growing Pigs Assessed Using Artificial...

Area of Science:

• Animal Science
• Agricultural Engineering
• Ethology

Background:

• Rearing density significantly impacts pig productivity and welfare.
• Understanding the behavioral and physiological effects of varying space allowance is crucial for optimizing pig farming.
• Previous research has indicated potential links between density and stress, but detailed mechanisms require further investigation.

Purpose of the Study:

• To evaluate the effects of increased space allowance on the growth performance, agonistic behavior, and physiological stress indicators in growing pigs.
• To compare high rearing density (HRD) with low rearing density (LRD) conditions.
• To assess the utility of AI-driven behavioral monitoring in pig production.

Main Methods:

• Seventy-six 12-week-old pigs were housed in either HRD (12 pigs/pen) or LRD (7 pigs/pen) for 28 days.
• Growth performance (body weight, feed intake, feed conversion ratio) was measured weekly.
• Agonistic behaviors were monitored using RGB cameras and analyzed with a YOLOv8-based AI model.
• Physiological stress indicators included ear base temperature, lesion scores, plasma glucose, free fatty acids, cortisol, and ear base temperature.

Main Results:

• Pigs in LRD conditions showed significantly higher body weight, daily gain, and feed intake, alongside a lower feed conversion ratio compared to HRD pigs (p < 0.01).
• Increased space allowance led to a significant reduction in agonistic behaviors, lesion scores, plasma glucose, free fatty acids, cortisol levels, and ear base temperature (p < 0.05).
• The AI model demonstrated high accuracy in detecting specific behaviors like aggression, ear biting, and tail biting.

Conclusions:

• Providing greater space allowance (0.97 m²/pig) significantly enhances pig growth performance and welfare compared to lower space allowance (0.57 m²/pig).
• Reduced rearing density effectively mitigates stress-related behaviors and physiological responses in growing pigs.
• AI-based monitoring systems offer a valuable tool for objective behavioral assessment in commercial pig production, aiding in welfare and productivity improvements.