The transition from individual gestation stalls to group housing for breeding sows represents the most significant structural change in pig farming welfare in recent decades. Understanding the welfare science and management requirements of group housing systems enables producers to maximise the welfare benefits while managing the challenges.
Welfare Benefits of Group Housing
Research comparing group-housed to stall-housed sows consistently demonstrates:
- Lower cortisol and stress hormone levels in group-housed sows
- Reduced stereotypy prevalence (bar-biting, rooting on concrete reduce dramatically when sows have space to move)
- Better musculoskeletal health from regular locomotion
- Expression of normal social behaviours and formation of dominance hierarchies
- Greater ability to thermoregulate through postural adjustments and location choice
Electronic Sow Feeding (ESF) Systems
ESF systems are the most widely adopted group housing technology. Individual electronic ear tags identify each sow entering a feeding station — each receives her individually programmed daily ration before exiting. Advantages include:
- Precise individual nutrition management (crucial for body condition maintenance)
- Automated recording of individual feed intake, weight, and behaviour
- Compatibility with large group sizes (10–60+ sows)
- Early detection of sick or anestrous sows through feeding pattern changes
Aggression Management
Aggression at group mixing is an inherent welfare challenge in group systems. Key management strategies:
- Mixing sows immediately after weaning (before grouping estrus synchrony develops) rather than post-insemination reduces early pregnancy loss from fighting
- Providing sufficient space (2.25m² minimum per sow) reduces resource competition
- Multiple feeding, water, and lying areas prevent bottlenecks
- Removing sows with excessive injuries promptly — chronic losers require individual management
- Providing abundant straw and manipulable material reduces redirected aggression
Lameness in Group Housing
Lameness is a welfare concern in group systems, particularly on slatted or concrete floors. Solid concrete or rubber-surfaced floors reduce slip injuries and foot lesions. Regular foot assessment as part of herd health monitoring enables early treatment. Body condition at culling (low BCS, severe lameness) reflects welfare status of the system over time.
Monitoring and Assessment
Welfare Quality® protocol assessments for group-housed sows include bursae, lameness, lesions, and body condition scoring. Regular implementation of these assessments identifies welfare problems enabling targeted management intervention. Benchmark comparison with other producers drives continuous improvement.