The 4-week lactation period: welfare challenges and evidence-based solutions
The lactation period — typically 21-28 days when sows nurse piglets — represents intense physiological and behavioral demands. Sows must simultaneously produce 8-12L of milk daily, manage 12-14 hungry piglets, and cope with confinement that prevents natural maternal behaviors. Welfare during this period affects both sow and piglet outcomes.
Standard farrowing crates confine sows for 3-5 weeks from shortly before farrowing through weaning. The welfare costs are multiple: inability to express pre-parturient nesting behavior (strong motivation for 12-24 hours before farrowing), inability to respond to piglet distress calls with movement, physical discomfort from prolonged confinement, and psychological frustration. Alternatives including free farrowing and temporary confinement systems are being adopted in welfare-committed operations.
Lactation is the most nutritionally demanding period in the sow's productive life. Underfed lactating sows mobilize excessive body condition, compromising their welfare, subsequent reproductive performance, and immune function. Key welfare requirements: ad libitum access to high-quality feed meeting elevated nutritional demands; multiple daily meals; water access at minimum 20L/day (sows can drink 30-40L in hot weather). Sows housed in groups after weaning may compete aggressively — timing weaning so sows are in similar body condition reduces dominance-related welfare problems.