Assessment of a group-housing system for gestating sows: Effects of space allowance and pen size on the incidence of superficial skin lesions, changes in body condition, and farrowing performance

Abstract

Objectives: To determine short-term effects of converting a gestation barn from individual stalls to group housing and effects of manipulating space allowance and pen size on body condition, farrowing performance, and skin lesions. Materials and methods: Pregnant multiparous Yorkshire sows (N = 285) were housed in static groups of 11 to 31 sows in SMALL (34.0 to 49.5 m2) or LARGE pens (72.5 to 74.5 m2) with 2.3 m2 (n = 2,2), 2.8 m2 (n = 3,2) or 3.2 m2 (n = 4,2) per sow. A reference population of 98 sows was housed in gestation stalls. Sows were scored for body condition upon entering and leaving their respective housing treatments. Shoulder skin lesions were assessed 24 hours premixing, 24 hours postmixing, and weekly thereafter for 5 weeks. Liveborn piglets, stillborn piglets, and individual piglet birth weights were recorded for each sow. Results: Body condition was not affected by group housing at any space allowance or pen size (P > .05). Group-housed sows had substantial numbers of skin lesions 24 hours postmixing, but these were not affected by space allowance or pen size (P > .05), and they decreased significantly over time (P < .01). Group-housed sows had larger litter sizes (P < .05) and slightly heavier piglets (P < .05) than sows in stalls. Implications: The conversion from individual stalls to group housing did not affect body condition or reduce reproductive performance of sows in this herd. Shoulder scratches were a short-term consequence of aggression that occurs after mixing.