Severe feather-pecking in non-cage laying hens and some associated and predisposing factors: a review

Severe feather-pecking (SFP), whereby birds vigorously peck at and pull out the feathers of conspecifics, is an extremely injurious, highly prevalent behaviour. It has acute negative impacts on the egg industry worldwide, in terms of both animal welfare and production efficiency. A large volume of research has been conducted to investigate the underlying causes. However, although many contributing factors have been identified, it remains largely...