Space allowance and high fiber diet impact performance and behavior of group-kept gestating sows

Identifying and optimizing housing and management systems that improve the well-being of the gestating sow is essential to sustaining animal agriculture. Therefore, the impact of 2 floor-space allowances and a high-fiber gestation diet on dry group-housed sows were evaluated using multiple measures of well-being. Groups of 10 multiparous sows/pen (n = 221) were assigned randomly to treatments in a 2 × 2 factorial arrangement to either a corn-soybean meal diet (CTL) or corn-soybean meal diet supplemented with soybean hulls and wheat middlings (FBR), and floor-space allowance of either 1.7 or 2.3 m(2)/sow. Sow BW, backfat (BF), and body condition score (BCS) were all recorded on d 34, 65, 90, and 110 of gestation, whereas skin lesions were scored on d 34, every 2 d for the first 2-wk postmixing, and then biweekly throughout gestation. Blood sample was collected only on d 34 for cortisol (baseline), and samples were collected on d 90 of gestation for other measures including cortisol. Behavior was registered on multiple days throughout gestation. Sows fed FBR and kept at 1.7 m(2) produced heavier litter and weaning weights and greater number of piglets born alive, compared to sows fed FBR but kept at 2.3 m(2) of floor space (diet × floor space, P ≤ 0.04). Sows fed FBR and kept at 1.7 m(2) performed fewer oral-nasal-facial and sham-chew behaviors than sows fed CTL and kept at the same floor space (diet × floor space, P ≤ 0.044). Sows kept at 1.7 m(2) of floor space had a greater (P < 0.05) total lesion severity score than sows kept at 2.3 m(2)/sow, and vulva lesion scores were more (P < 0.02) severe among CTL-fed sows than FBR-fed sows. Parities 2 and 3 sows fed FBR and kept at 1.7 m(2) of floor space were heavier (P < 0.001) than sows fed the same diet but kept at 2.3 m(2). These results indicate that keeping small groups of pregnant sows at a minimum floor-space allowance of 1.7 m(2)/sow and floor feeding these sows a high-fiber diet can improve short-term sow well-being.