Blinders (poultry)

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From the U.S. Patent "Device to prevent picking in poultry" filed in 1935 Blinders (poultry).jpg
From the U.S. Patent "Device to prevent picking in poultry" filed in 1935

Blinders, also known as peepers, are devices fitted to, or through, the beaks of poultry to block their forward vision and assist in the control of feather pecking, cannibalism and sometimes egg-eating. A patent for the devices was filed as early as 1935. [1] They are used primarily for game birds, pheasant and quail, but also for turkeys and laying hens. Blinders are opaque and prevent forward vision, unlike similar devices called spectacles which have transparent lenses. Blinders work by reducing the accuracy of pecking at the feathers or body of another bird, rather than spectacles which have coloured lenses and allow the bird to see forwards but alter the perceived colour, particularly of blood. Blinders are held in position with a circlip arrangement or lugs into the nares of the bird, or a pin which pierces through the nasal septum. They can be made of metal (aluminium), neoprene or plastic, and are often brightly coloured making it easy to identify birds which have lost the device. Some versions have a hole in the centre of each of the blinders, thereby allowing restricted forward vision.[ citation needed ]

Contents

Benefits

In pheasants, blinders have been shown to reduce the incidence of birds pecking each other and damage to the feathers or skin. [2]

In laying hens, blinders have been shown to reduce feather pecking, improve food utilisation (due to less spillage) and increase egg production. [3]

Welfare concerns

Blinders which require a pin to pierce the nasal septum and hold the device in position almost certainly cause pain to the bird. In the UK, the use of these devices is illegal on welfare grounds. The Department for Environment, Food and Rural Affairs in their Codes of Recommendations for the Welfare of Livestock: Laying Hens, states: "The Welfare of Livestock (Prohibited Operations) Regulations 1982 (S.I. 1982 No.1884) prohibits ...the fitting of any appliance which has the object or effect of limiting vision to a bird by a method involving the penetration or other mutilation of the nasal septum." [4]

Studies on pin-less blinders indicate these devices are at least temporarily distressful to the birds. In pheasants, fitting blinders causes an increase in head shaking and scratching, and increases in damage to the beak and nostrils of the bird. [2] Fitting pin-less blinders to laying hens leads to reduced activity, increased resting, adjustment problems in feeding, stereotypic head shaking and protracted displacement neck preening for a month after fitting. [3] In another study on laying hens, mortality was greater among hens wearing blinders compared to hens that had been beak-trimmed. [5]

See also

Related Research Articles

Poultry Domesticated birds kept by humans for their eggs, meat, or feathers

Poultry are domesticated birds kept by humans for their eggs, their meat or their feathers. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes. The term also includes birds that are killed for their meat, such as the young of pigeons but does not include similar wild birds hunted for sport or food and known as game. The word "poultry" comes from the French/Norman word poule, itself derived from the Latin word pullus, which means small animal.

Debeaking The trimming of a birds beak, usually performed on domesticated birds

Debeaking, beak trimming, or beak conditioning 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 the upper beak. A similar but separate practice, usually performed by an avian veterinarian or an experienced birdkeeper, involves clipping, filing or sanding the beaks of captive birds for health purposes – in order to correct or temporarily alleviate overgrowths or deformities and better allow the bird to go about its normal feeding and preening activities. Amongst raptor keepers, this practice is commonly known as "coping".

Domestic turkey Species of bird

The domestic turkey is a large fowl, one of the two species in the genus Meleagris and the same species as the wild turkey. Although turkey domestication was thought to have occurred in central Mesoamerica at least 2,000 years ago, recent research suggests a possible second domestication event in the southwestern United States between 200 BC and AD 500. However, all of the main domestic turkey varieties today descend from the turkey raised in central Mexico that was subsequently imported into Europe by the Spanish in the 16th century.

Broiler

A broiler is any chicken that is bred and raised specifically for meat production. Most commercial broilers reach slaughter weight between four and seven weeks of age, although slower growing breeds reach slaughter weight at approximately 14 weeks of age. Typical broilers have white feathers and yellowish skin. Broiler or sometimes broiler-fryer is also used sometimes to refer specifically to younger chickens under 4.5 pounds, as compared with the larger roasters.

Free range Method of farming where animals can roam freely outdoors

Free range denotes a method of farming husbandry where the animals, for at least part of the day, can roam freely outdoors, rather than being confined in an enclosure for 24 hours each day. On many farms, the outdoors ranging area is fenced, thereby technically making this an enclosure, however, free range systems usually offer the opportunity for the extensive locomotion and sunlight that is otherwise prevented by indoor housing systems. Free range may apply to meat, eggs or dairy farming.

Feather-plucking Maladaptive, behavioural disorder commonly seen in captive birds

Feather-plucking, sometimes termed feather-picking, feather damaging behaviour or pterotillomania, is a maladaptive, behavioural disorder commonly seen in captive birds which chew, bite or pluck their own feathers with their beak, resulting in damage to the feathers and occasionally the skin. It is especially common among Psittaciformes, with an estimated 10% of captive parrots exhibiting the disorder. The areas of the body that are mainly pecked or plucked are the more accessible regions such as the neck, chest, flank, inner thigh and ventral wing area. Contour and down feathers are generally identified as the main target, although in some cases, tail and flight feathers are affected. Although feather-plucking shares characteristics with feather pecking commonly seen in commercial poultry, the two behaviours are currently considered to be distinct as in the latter, the birds peck at and pull out the feathers of other individuals.

Forced molting Practice of artificially provoking a flock to molt simultaneously

Forced molting, sometimes known as induced molting, is the practice by some poultry industries of artificially provoking a flock to molt simultaneously, typically by withdrawing food for 7–14 days and sometimes also withdrawing water for an extended period. Forced molting is usually implemented when egg-production is naturally decreasing toward the end of the first egg-laying phase. During the forced molt, the birds cease producing eggs for at least two weeks, which allows the bird's reproductive tracts to regress and rejuvenate. After the molt, the hen's egg production rate usually peaks slightly lower than the previous peak, but egg quality is improved. The purpose of forced molting is therefore to increase egg production, egg quality, and profitability of flocks in their second or subsequent laying phases, by not allowing the hen's body the necessary time to rejuvenate during the natural cycle of feather replenishment.

Battery cages are a housing system used for various animal production methods, but primarily for egg-laying hens. The name arises from the arrangement of rows and columns of identical cages connected together, in a unit, as in an artillery battery. Although the term is usually applied to poultry farming, similar cage systems are used for other animals. Battery cages have generated controversy between advocates for animal welfare and industrial producers.

Poultry farming Part of animal husbandry

Poultry farming is the form of animal husbandry which raises domesticated birds such as chickens, ducks, turkeys and geese to produce meat or eggs for food. It has originated from the agricultural era. Poultry – mostly chickens – are farmed in great numbers. More than 60 billion chickens are killed for consumption annually. Chickens raised for eggs are known as layers, while chickens raised for meat are called broilers.

Dust bathing

Dust bathing is an animal behavior characterized by rolling or moving around in dust, dry earth or sand, with the likely purpose of removing parasites from fur, feathers or skin. Dust bathing is a maintenance behavior performed by a wide range of mammalian and avian species. For some animals, dust baths are necessary to maintain healthy feathers, skin, or fur, similar to bathing in water or wallowing in mud. In some mammals, dust bathing may be a way of transmitting chemical signals to the ground which marks an individual's territory.

Feather pecking When one bird repeatedly pecks at the feathers of another

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, broiler chickens and is sometimes seen in farmed ostriches. Feather pecking occurs when one bird repeatedly pecks at the feathers of another. The levels of severity may be recognized as mild and severe. Gentle feather pecking is considered to be a normal investigatory behaviour where the feathers of the recipient are hardly disturbed and therefore does not represent a problem. In severe feather pecking, however, the feathers of the recipient are grasped, pulled at and sometimes removed. This is painful for the receiving bird and can lead to trauma of the skin or bleeding, which in turn can lead to cannibalism and death.

Abnormal behaviour of birds in captivity

Abnormal behavior of birds in captivity has been found to occur among both domesticated and wild birds. Abnormal behavior can be defined in several ways. Statistically, 'abnormal' is when the occurrence, frequency or intensity of a behaviour varies statistically significantly, either more or less, from the normal value. This means that theoretically, almost any behaviour could become 'abnormal' in an individual. Less formally, 'abnormal' includes any activity judged to be outside the normal behaviour pattern for captive birds of that particular class or age. For example, running rather than flying may be a normal behaviour and regularly observed in one species, however, in another species it might be normal but becomes 'abnormal' if it reaches a high frequency, or in another species it is rarely observed and any incidence is considered 'abnormal'. This article does not include 'one-off' behaviours performed by individual birds that might be considered abnormal for that individual, unless these are performed repeatedly by other individuals in the species and are recognised as part of the ethogram of that species.

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. Vent pecking frequently occurs immediately after an egg has been laid when the cloaca often remains partly everted exposing the mucosa, red from the physical trauma of oviposition or bleeding if the tissue is torn by her laying an egg. Vent pecking clearly causes pain and distress to the bird being pecked. Tearing of the skin increases susceptibility to disease and may lead to cannibalism, with possible evisceration of the pecked bird and ultimately, death.

Toe pecking, an abnormal behaviour of birds in captivity, occurs when one bird pecks the toes of another using its beak. This behaviour has been reported in hens and ostriches. Studies have shown that hens exposed to toe pecking have significantly enlarged adrenal glands, indicating increased physiological stress. Hens exposed to toe pecking will step off a raised platform more quickly than control hens, possibly suggesting a heightened fear of elevation. They have also been reported to show depressive behaviour when afflicted by toe-pecking. The act of toe pecking leads to open wounds which are viable for infection and disease to develop. In severe forms, toe pecking can be classified as a cannibalistic behaviour and has been reported as a cause of mortality.

Cannibalism in poultry

Cannibalism in poultry is the act of one individual of a poultry species consuming all or part of another individual of the same species as food. It commonly occurs in flocks of domestic hens reared for egg production, although it can also occur in domestic turkeys, pheasants and other poultry species. Poultry create a social order of dominance known as pecking order. When pressure occurs within the flock, pecking can increase in aggression and escalate to cannibalism. Cannibalism can occur as a consequence of feather pecking which has caused denuded areas and bleeding on a bird's skin. Cannibalism can cause large mortality rates within the flock and large decreases in production due to the stress it causes. Vent pecking, sometimes called 'cloacal cannibalism', is considered to be a separate form of cannibalistic pecking as this occurs in well-feathered birds and only the cloaca is targeted. There are several causes that can lead to cannibalism such as: light and overheating, crowd size, nutrition, injury/death, genetics and learned behaviour. Research has been conducted to attempt to understand why poultry engage in this behaviour, as it is not totally understood. There are known methods of control to reduce cannibalism such as crowd size control, beak trimming, light manipulation, perches, selective genetics and eyewear.

A furnished cage, sometimes called enriched cage, colony cage or modified cage, is a type of cage used in poultry farming for egg laying hens. Furnished cages 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 over non-cage systems. Many design features of furnished cages have been incorporated because research in animal welfare science has shown them to be of benefit to the hens.

Chicken eyeglasses Small eyeglasses made for chickens

Chicken eyeglasses, also known as chickens specs, chicken goggles, generically as pick guards and under other names, were small eyeglasses made for chickens intended to prevent feather pecking and cannibalism. They differ from blinders as they allowed the bird to see forward whereas blinders do not. One variety used rose-colored lenses as the coloring was thought to prevent a chicken wearing them from recognizing blood on other chickens which may increase the tendency for abnormal injurious behavior. They were mass-produced and sold throughout the United States as early as the beginning of the 20th century.

Overview of discretionary invasive procedures on animals

Numerous procedures performed on domestic animals are usually more invasive than purely cosmetic alterations, but differ from types of veterinary surgery that are performed exclusively for urgent health reasons. Such procedures have been grouped together under the technical term 'mutilatory' by the Royal College of Veterinary Surgeons in a report describing the reasons for their being conducted and their welfare consequences, and by others.

Pecking

Pecking is the action of a bird using their beak to search for food or otherwise investigate an object or area by tapping it. Pecking can also be used by a bird to attack or fight another bird.

References

  1. US 2079107 . See also however the earlier patent US 730918 .
  2. 1 2 "Defra report "To study the effects of the application of bits and spectacles in game birds"" . Retrieved 21 December 2011.
  3. 1 2 Arbi, A., Cumming, R.B. and Wodzicka-Tomaszewska., M., (1983). Effects of vision restricting "polpeepers" on the behaviour of laying hens during adaptation, feeding, on general activity, agonistic behaviour and pecking damage. British Poultry Science, 24: 371-381
  4. Department of Environment, Food & Rural Affairs (July 2002). "Mutilations" (PDF). Codes of Recommendations for the Welfare of Livestock: Laying Hens: 21.
  5. Robinson, D., (1979). Effects of cage shape, colony size, floor area and cannibalism preventatives on laying performance. British Poultry Science, 20: 345-356. doi : 10.1080/00071667908416592