Cannibalism (poultry)
Encyclopedia
Cannibalism is a behavioural problem that occurs most frequently amongst domestic hens
reared for egg production, although it can also occur amongst domestic turkeys, pheasants reared as gamebirds, and other poultry
species. Cannibalism occurs when one bird pecks at the skin of another and devours their flesh. Cannibalism can follow on from severe feather pecking
which has caused denuded areas on the bird. Cannibalism can result in significant mortality within the flock and also causes a decrease in production as the pecked birds become stressed. Vent pecking
, sometimes called 'cloacal cannibalism', is considered to be a separate form of cannibalistic pecking as this can be observed in well-feathered birds and the vent or cloaca
is targetted exclusively.
s. For example, hens in the wild often scratch at the soil to search for seeds, insects and even larger animals such as lizard
s or young mice
, although they are mainly herbivorous in adulthood. Feather pecking is often the initial cause of an injury which then attracts the cannibalistic pecking of other birds – perhaps as re-directed foraging or feeding behaviour. In the close confines of modern farming systems, the increased pecking attention is easily observed by multiple birds which join in the attack, and often the escape attempts of the cannibalised bird attract more pecking attention.
with a hen had lower mortality levels due to feather pecking and cannibalism compared to non-brooded chicks. This may indicate the hen guides the chicks to peck at more rewarding substrates, such as food or litter.
systems, followed by barns, furnished cages
and best in conventional or battery cages.
is the most common method of preventing or reducing injuries by cannibalism. In a 3-year study of floor-housed laying hens, death by cannibalism was reported as 7% in beak-trimmed birds but was increased to 18% in non-trimmed birds.
Chicken
The chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...
reared for egg production, although it can also occur amongst domestic turkeys, pheasants reared as gamebirds, and other poultry
Poultry
Poultry are domesticated birds kept by humans for the purpose of producing eggs, meat, and/or feathers. These most typically are members of the superorder Galloanserae , especially the order Galliformes and the family Anatidae , commonly known as "waterfowl"...
species. Cannibalism occurs when one bird pecks at the skin of another and devours their flesh. Cannibalism can follow on from severe feather pecking
Feather pecking
Feather pecking is a behavioural problem that occurs most frequently amongst domestic hens reared for egg production, although it does occur in other poultry such as pheasants, turkeys, ducks and is sometimes seen in farmed ostriches. Feather pecking occurs when one bird repeatedly pecks at the...
which has caused denuded areas on the bird. Cannibalism can result in significant mortality within the flock and also causes a decrease in production as the pecked birds become stressed. Vent pecking
Vent pecking
Vent pecking is an abnormal behaviour of birds performed primarily by commercial egg-laying hens. It is characterised by pecking damage to the cloaca, the surrounding skin and underlying tissue...
, sometimes called 'cloacal cannibalism', is considered to be a separate form of cannibalistic pecking as this can be observed in well-feathered birds and the vent or cloaca
Cloaca
In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, reproductive, and urinary tracts of certain animal species...
is targetted exclusively.
Motivational Basis
Poultry species which exhibit cannibalism are omnivoreOmnivore
Omnivores are species that eat both plants and animals as their primary food source...
s. For example, hens in the wild often scratch at the soil to search for seeds, insects and even larger animals such as lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s or young mice
MICE
-Fiction:*Mice , alien species in The Hitchhiker's Guide to the Galaxy*The Mice -Acronyms:* "Meetings, Incentives, Conferencing, Exhibitions", facilities terminology for events...
, although they are mainly herbivorous in adulthood. Feather pecking is often the initial cause of an injury which then attracts the cannibalistic pecking of other birds – perhaps as re-directed foraging or feeding behaviour. In the close confines of modern farming systems, the increased pecking attention is easily observed by multiple birds which join in the attack, and often the escape attempts of the cannibalised bird attract more pecking attention.
Development
Chicks broodedAvian incubation
Incubation refers to the process by which certain oviparous animals hatch their eggs, and to the development of the embryo within the egg. The most vital factor of incubation is the constant temperature required for its development over a specific period. Especially in domestic fowl, the act of...
with a hen had lower mortality levels due to feather pecking and cannibalism compared to non-brooded chicks. This may indicate the hen guides the chicks to peck at more rewarding substrates, such as food or litter.
Prevalence
Cannibalism among layer hen flocks is highly variable and when it is not problematic, mortalities among production systems are generally similar. Published data on the prevalence of cannibalism could be misleading due to the inclusion of vent-pecking by some researchers but not others. Mortalities, due mainly to cannibalism, can be up to 15% in egg laying flocks housed in aviaries, straw yards, and free-range systems. Because egg laying strains of chickens can be kept in smaller group sizes in cage systems, cannibalism is reduced leading to a lowered trend in mortality as compared to non-cage systems. In a study which examined ‘skin damage’ (most of which would have been cause by pecking) on hens at the end of their productive life, damage was worst in hens from free rangeFree range
thumb|250px|Free-range chickens being fed outdoors.Free range is a term which outside of the United States denotes a method of farming husbandry where the animals are allowed to roam freely instead of being contained in any manner. In the United States, USDA regulations apply only to poultry and...
systems, followed by barns, furnished cages
Furnished cages
Furnished cages, sometimes called ‘enriched’ or ‘modified’ cages, are cages for egg laying hens which have been designed to overcome some of the welfare concerns of battery cages whilst retaining their economic and husbandry advantages, and also provide some of the welfare advantages of non-cage...
and best in conventional or battery cages.
Beak-trimming
Beak-trimmingDebeaking
Debeaking, also called beak-trimming is the partial removal of the beak of poultry, especially layer hens and turkeys although it may also be performed on quail and ducks. Most commonly, the beak is shortened permanently, although regrowth can occur. The trimmed lower beak is somewhat longer than...
is the most common method of preventing or reducing injuries by cannibalism. In a 3-year study of floor-housed laying hens, death by cannibalism was reported as 7% in beak-trimmed birds but was increased to 18% in non-trimmed birds.
Group size
Increased group sizes in larger cages or floor systems can elevate the risk of cannibalism and feather pecking, probably due to the spread of the behaviour through social learning.Light manipulations
Lights are sometimes provided in nest-boxes to attract hens to use the nests, but this practice has been correlated with an increased risk of cannibalism.Perches
Rearing chicks with access to perches by 4 weeks of age has been associated with increased use of perches, and reduced cannibalism, in adulthood.Selective breeding & Genetics
A sib-selection programme has genetically selected a low mortality line which shows decreased mortality from cannibalism compared to a control line.See also
- Abnormal behaviour of birds in captivityAbnormal behaviour of birds in captivity-Abnormal behaviour :When housed under captive or commercial conditions, birds often show a range of abnormal behaviours. These are often self-injurious or harmful to other individuals, and include:*Feather pecking*Cannibalism*Vent pecking...
- Battery cages
- ChickenChickenThe chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...
- Feather peckingFeather peckingFeather pecking is a behavioural problem that occurs most frequently amongst domestic hens reared for egg production, although it does occur in other poultry such as pheasants, turkeys, ducks and is sometimes seen in farmed ostriches. Feather pecking occurs when one bird repeatedly pecks at the...
- Furnished cagesFurnished cagesFurnished cages, sometimes called ‘enriched’ or ‘modified’ cages, are cages for egg laying hens which have been designed to overcome some of the welfare concerns of battery cages whilst retaining their economic and husbandry advantages, and also provide some of the welfare advantages of non-cage...
- Poultry farmingPoultry farmingPoultry farming is the raising of domesticated birds such as chickens, turkeys, ducks, and geese, for the purpose of farming meat or eggs for food. According to the Worldwatch Institute, 74 percent of the world's poultry meat, and 68 percent of eggs are produced in ways that are described as...
- SavagingSavagingIn animal science, savaging is overt aggression, usually including cannibalistic infanticide of newborn offspring, by a mother animal. It is particularly prevalent among pigs, where it affects up to 5% of gilts....
- Toe peckingToe peckingToe pecking is a relatively rare abnormal behaviour of birds in captivity. It involves one bird pecking the toes of another and has been reported in hens and ostriches...
- Vent peckingVent peckingVent pecking is an abnormal behaviour of birds performed primarily by commercial egg-laying hens. It is characterised by pecking damage to the cloaca, the surrounding skin and underlying tissue...