Cannibalism is aggressive behavior of chickens that may begin by feather pecking by socially dominant birds. Cannibalism usually occurs when the birds are stressed by a poor management practice. Once becoming stressed, one bird begins picking the feathers, head, comb,wattles, toes or vent of another bird. Once an open wound or blood is visible on the bird, the vicious habit of cannibalism can spread rapidly through the entire flock. If you notice the problem soon after it begins, cannibalism can be held in check. However, if the problem is allowed to get out of hand it can be very costly.
Cannibalism will lower the birds value due to torn and damaged flesh, poor feathering and can result in high death losses. In addition to the loss of birds due to pecking trauma, cannibalism often leads to transmission of infectious diseases. Once this habit gets out of hand it is difficult to eliminate. All forms of commercial poultry can experience cannibalism as it a behavioral problem that can develop into a habit that will persist and spread within a flock as a learned behavior, even after the initial causes of the behavior have been corrected.
It may be caused by:
- crowding -excessive light intensity -nutritional imbalances are correlated with its occurrence. -in overweight pullets entering egg production or hens in production, mucosa will protrude from the vent during and after egg laying, and this red tissue attracts pecking. -insufficient feeder space. If the birds have to fight for food and water, or if the birds are always hungry they will increase pecking. Be sure that birds have free access to water and feed at all times. -mineral and vitamin deficiencies -skin injuries, and failure to remove any dead birds daily often lead to cannibalism. -bright light intensity -high room temperature -poor ventilation, high humidity, low salt, trace nutrient deficiency -insufficient feeding or drinking space -nervous and excitable birds (hereditary) -external parasites, access to sick or injured birds -stress from moving, boredom and idleness -housing birds of different appearance together and birds prolapsing during egg-laying times. -Slow feathering birds are most prone to cannibalism
How to control: As cannibalism can become a learned behavior, it can be difficult to treat once it has started in a flock. Therefore, prevention should be the main aim and as such, good husbandry practices should aim to minimize the stressors listed above as potential causes for cannibalism. Control depends on correcting or reducing the above risk factors. Interventions include: -correcting an inadequate diet and replacing mash feed with pelleted feed -rearing birds on floor litter rather than slats -reducing light intensity or darkening the facilities by using red bulbs. -providing perches as a refuge for targeted birds. -Environmental enrichment such as hanging white or yellow strings may be beneficial. -Trimming of the sharp tip of the upper and sometimes lower beak reduces the damage that is caused by aggressive pecking. This will decrease skin trauma from pecking; this may be done at 1 day of age and repeated between 6 and 12 week of age in maturing pullets. The tip of the beak can also be treated by infrared heat on the day of hatching, which results in a shortened beak with minimal stress. Cauterization is required to provide hemostasis during beak trimming in older poultry.
-The injured and aggressive birds can be rapidly identified and removed from the flock -Use of high fibre diets (fresh greens like clover grass or weeds) each day. It is believed that high fibre diets enhance gut development and gizzard function, which in turn help reduce aggressive behaviour in hens. -Applying an "anti-peck" ointment or pine tar on any damaged birds usually stops pecking