Types and clinical presentation of damaging behaviour - feather pecking and cannibalism in birds

Abstract

Behavioural disorders, including feather pecking and cannibalism, are a common problem in both domestic and wild birds. The consequences of this behaviour on welfare of birds incur serious economic losses. Pecking behaviour in birds is either normal or injurious. The type of normal pecking behaviour includes non-aggressive feather pecking – allopreening and autopreening. Aggressive feather pecking aimed at maintenance and establishment of hierarchy in the flock is not associated to feathering damage. Injurious pecking causes damage of individual feathers and of feathering as a whole. Two clinical presentations of feather pecking are known in birds. The gentle feather pecking causes minimum damage; it is further divided into normal and stereotyped with bouts; it could however evolve into severe feather pecking manifested with severe pecking, pulling and removal, even consumption of feathers of the victim, which experiences pain. Severe feather pecking results in bleeding from feather follicle, deterioration of plumage and appearance of denuded areas on victim’s body. Prolonged feather pecking leads to tissue damage and consequently, cannibalism. The nume­rous clinical presentations of the latter include pecking of the back, abdomen, neck and wings. Vent pecking and abdominal pecking incur important losses especially during egg-laying. In young birds, pulling and pecking of toes of legs is encountered. All forms of cannibalistic pecking increase morta­lity rates in birds. Transition of various pecking types from one into another could be seen, while the difference between gentle, severe feather pecking and cannibalism is not always distinct.

Effective Strategies for Mitigating Feather Pecking and Cannibalism in Cage-Free W-36 Pullets

“…Feather pecking (FP) is a serious welfare issue in the poultry industry, associated with damage to the feathers, injury to body parts, and even death due to cannibalism [1][2][3][4][5]. Based on both the cause and its effects, FP is mainly categorized into five different types: (a) aggressive pecking (AP; pecking feathers aggressively but not necessarily resulting in injury or damage to the feather), (b) gentle FP (GFP; pecking the tips of feathers), (c) severe FP (SFP; forcefully and repeatedly pecking, pulling, and often removing feathers from other birds, causing skin damage or bleeding), (d) denuded area tissue pecking (DP), and (e) vent pecking (VP) [6,7]. The GFP is considered normal social behavior, while SFP may result in aggressive tissue pecking, leading to VP and cannibalism.…”

“…In addition, pulling out feathers results in fewer feathers from birds causes economic losses for producers because birds with fewer feathers lose heat faster and require more feed consumption to stay warm [11]. In severe cases, pecking can lead to cannibalism, resulting in the victim bird's death [7,12].…”