Reducing stocking density improves behaviour in broilers breeders

Broiler breeder males often show rough behaviour towards females during mating, which may cause fear and feather and skin damage in the females. Our hypothesis was that the high stocking density applied under commercial conditions hampers correct learning and performance of mating behaviour. Broiler breeders (Ross 308) were housed at standard stocking density (14 females/m2 or 8 males/m2 during rearing, 8 birds/m2 during production) or low stocking density (7 females/m2 or 5 males/m2 during rearing, 5 birds/m2 during production) from day 1 to 60 weeks of age. Standard management was applied. During production there were 10% males per group and group size was 150 birds. The experiment was of a 2 x 2 factorial design, resulting in 4 treatment groups: SL (standard stocking density during rearing, low stocking density during production), SS, LS and LL; N=8 groups/treatment. Behaviour and plumage condition were scored during rearing and production. In particular stocking density during production affected mating behaviour. LL and SL groups had more successful copulations at all ages (e.g., 0.51, 0.33, 0.22, 0.21 successful copulations/male/5 min at 30 weeks for LL, SL, SS, LS; P