Mels, C., Niebuhr, K., Futschik, A. et al. 2022. Predictors for plumage damage and bloody lesions indicative of feather pecking in pullets reared in aviaries. Applied Animal Behaviour Science 250, 105607.

Feather pecking remains a serious problem in poultry farming. This study aimed to identify risk factors for plumage damage as a proxy for feather pecking, and the predictive value of practical animal-based parameters. Data were collected in 100 flocks on 28 rearing farms in Austria, recording plumage damage in the 10th and bloody lesions in the 6th, 10th and 16th weeks of age; housing (e.g. pre-rearing on another farm, early rearing on the floor or aviary), management (e.g. provision of litter) and human-animal relationship (e.g. avoidance distance, farmers’ attitudes). Linear mixed models were calculated for plumage damage and generalized linear models for bloody lesions in the 10th week. Early floor-rearing of pullets with access to litter, instead of confinement in the aviary in the first weeks without access to litter, was associated with less plumage damage (P = 0.011). A shorter pre-rearing period on a different farm was associated with less plumage damage (P = 0.035). In organic flocks, bloody lesions tended to occur with a nearly three times lower probability with early floor-rearing than early aviary-rearing (P = 0.062) and when litter quantity in the 10th week was scored as high (P < 0.001). There were fewer down feathers on the ground when pullets had bloody lesions in the 10th week (P˂0.001). Farmers’ attitudes were associated with both plumage damage and bloody lesions; e.g. less plumage damage was observed when farmers ascribed more positive characteristics to pullets (P = 0.020). Avoidance of an unfamiliar human by the birds was associated with breed (P = 0.001) and was lower at higher stocking density (P = 0.005), but did not significantly predict plumage damage or bloody lesions. Farmers’ attitude analyses revealed that farmers who agreed more on the importance of regular contact had pullets with lower avoidance distance (P = 0.022). The results confirm the importance of access to litter from the first day of life onwards: early floor-rearing with access to litter can substantially reduce the risk of feather pecking compared to confinement in the aviary with chick paper only, in the first weeks of life. However, the pre-rearing period is best kept relatively short and appropriate litter later in life is important for the prevention of feather pecking. The absence of down feathers on the floor is easy to record on a regular basis for the early detection and potentially prevention of feather pecking. Farmers’ attitudes are important predictors for further variation in feather pecking between farms as well as in pullets’ fear of humans.