The physical design of pig housing systems fundamentally determines which behaviors pigs can express. Evidence-based pen design improves welfare by enabling natural behavior while reducing injury and disease.
Pen design is a fundamental determinant of pig welfare because it controls which behaviors are physically possible. A pig in a barren concrete slatted pen cannot root, cannot create distinct dunging and resting areas, and has limited ability to move away from aggressive pen mates. These are not minor inconveniences but restrictions on fundamental natural behaviors that pigs are strongly motivated to perform. Pen design that provides rooting substrate, appropriate space allowances, and social management opportunities enables pigs to express a much broader behavioral repertoire. The welfare improvement from good pen design is continuous and cumulative - it affects every moment of every pig's life for their entire productive period.