Skin lesions and callosities in group-housed pregnant sows: Animal-relatedwelfare indicators

An on-farm investigation of 55 herds of pregnant sows housed in various gro up-housing systems was carried out. Management factors, pen design and abno rmalities of the integument of 1177 pregnant sows were examined. The arithm etic mean of injured body regions was 1.49 as a total value per sow, 0.94 o n the front part of the body and 0.56 on the rear part of the body. Group s ize, the design of the feeding place and area per sow (within stable groups ) showed a significant influence on the extent of lesions. The limbs displa yed 3.53 callosities on average per sow. In littered systems the prevalence of callosities was significantly lower. Callosities were positively correl ated with decubital lesions. This investigation showed that lesion patterns on the skin do act as indicators of welfare. An adequately designed feedin g area, good management and the maintenance of groups with established soci al ranks can minimise fighting. A smooth lying area and the opportunity to move around reduce the incidence of callosities.