Developmental, Metabolic, and Other Noninfectious Disorders

This chapter covers disorders induced by the environment or management conditions and diseases that are not associated with a specific body system-conditions such as cannibalism or amyloidosis. It focuses on metabolic diseases of economic importance to the modern poultry industries. Cannibalism is the most severe outcome of both feather and vent pecking. Feather pecking is a major welfare problem. It is a behavior expressed by dominant birds on subordinates. Pecking may vary from pecking without removal of feathers to plucking of the feathers. Vent pecking is a separate form of pecking that also can be observed in well-feathered birds. It generally occurs soon after birds have come into lay. Amyloidosis is a well-recognized pathological disorder in birds, characterized by deposition of proteinaceous material between cells in various tissues and organs of the body. Amyloidosis caused by AA is frequently associated with an underlying infectious or inflammatory condition.