Pig Welfare: Nursery Management
The nursery phase — from weaning to approximately 10 weeks of age — is one of the most welfare-challenging periods for pigs. Abrupt separation from the sow, dietary change, social mixing, and novel environments occur simultaneously, creating significant physiological and psychological stress.
Understanding Weaning Stress
Piglets typically weaned at 21-28 days face a cascade of stressors. Cortisol levels spike dramatically post-weaning, immune function is temporarily suppressed, and intestinal architecture changes as the gut adapts from sow milk to solid feed. This vulnerable period coincides with exposure to pathogens from pen-mates and the environment.
Research shows that later weaning age (28 days vs 21 days) significantly reduces post-weaning diarrhoea, improves growth rates, and reduces antibiotic use. Where production systems allow, later weaning benefits both welfare and performance.
Thermal Comfort in Nursery Pens
Newly weaned piglets have limited thermoregulatory capacity. Recommended temperatures are 28-30°C at weaning, reducing by 2-3°C per week as pigs develop. Chilling suppresses feed intake, increases infection susceptibility, and causes huddling behaviour that can result in overlay injuries.
Effective nursery design includes solid, draught-free lying areas with supplemental heat (heat mats, lamp zones), perforated or slatted areas for dunging, and adequate ventilation that prevents chilling. Monitoring behavioural indicators — pigs spread out and comfortable vs. huddled — provides real-time welfare assessment.
Transition Nutrition
Post-weaning feed intake often drops sharply. High-quality starter diets with palatable ingredients (dried plasma, fish meal, lactose, cooked cereals) improve early feed intake and reduce gut damage. Liquid feeding systems can ease the transition from milk and maintain better feed consumption in the first week post-weaning.
Providing multiple small meals rather than ad libitum dry feed in the immediate post-weaning period supports smoother gut transition. Water availability is critical — dehydration compounds feed refusal and increases disease susceptibility.
Social Management and Mixing
Mixing unfamiliar piglets at weaning triggers aggression as hierarchies are established. Strategies to reduce mixing stress include keeping litter-mates together, minimising group size for initial housing, and providing multiple feeding and water points to reduce competition. Anti-agonistic compounds (e.g., yucca preparations) have limited but some evidence of benefit.
Environmental complexity — rooting substrate, hanging chains, spatial features — helps redirect aggression and supports psychological recovery from weaning stress.
Health Monitoring Protocols
Daily observation of nursery pigs should assess attitude, posture, respiratory rate, faecal consistency, and skin condition. Early identification of post-weaning enteritis (PWE) and respiratory disease allows prompt intervention, reducing suffering and preventing mortality. PRRS, PCV2, and Mycoplasma hyopneumoniae vaccination programmes should be timed appropriately given maternal antibody windows.
Key Welfare Indicators
- Pre-weaning mortality rate (<5% target)
- Post-weaning diarrhoea prevalence and severity
- Average daily gain in nursery phase
- Tail-biting and ear-biting incidence
- Antibiotic treatment rates
- Behavioural indicators of comfort (lying posture, feeding activity)