Cannibalism and feather pecking are a common behavioral problem in poultry worldwide. Incidents increase in overcrowded conditions, nutrient deficiencies, feed type, presence of excessive light intensity or variations, hot temperatures, stressful conditions, sheer boredom, and diseases causing lameness and inactivity. If a chicken is injured and there are bloodstains, broken skin, raw wounds and/or injured vent, it increases the occurrence of cannibalism in birds.
There are a number of different causes for increased incidents of feather pecking in birds, including:
- Housing Conditions: Overcrowded living conditions, excessive light, and not providing enough nest boxes or roosting space for flock members can result in feather pecking.
- Environmental Stresses: Birds exposed to high temperatures and occurrence of abrupt weather changes can stress birds, leading to aggressive behavior.
- Diet: When birds receive inadequate amounts of protein, phosphorus, and sodium in their diet, an excessive high-energy and low-fiber diet, or lack of fresh greens, they can develop aggressive behavior.
- Management-related: Since chickens tend to instinctively prey on the sick and injured, any injured birds should be relocated to a separate area, away from other birds until fully recovered. Flock size should include more than or less than 30 birds. When flocks have 30 birds, they tend to have more problems within their social hierarchy. Feather pecking can also occur more often in flocks which combine birds of different ages, breeds, colors, or sizes that have not grown up together.