Fighting of gilts after mixing is associated with early removals, altered litter sex ratio and lower piglet survival

Aggressive behaviour can compromise the welfare of group-housed gilts and sows and affect reproductive performance (Spoolder et al. 2009), but the extent of individual aggression is frequently unknown. Lesions resulting from fighting indicate the intensity and extent of aggressive encounters between sows (Bunter and Boardman 2015). The aim of this study was to investigate if lesions resulting from fighting amongst gilts were associated with subsequent reproductive outcomes for group-housed sows.