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Animal Welfare and Food Safety Aspects of Confining Broiler Chickens to Cages.

Shields S, Greger M - Animals (Basel) (2013)

Bottom Line: Cage environments are usually stocked at a higher density than open floor systems, and the limited studies available suggest that caging may lead to increased levels of fear and stress in the birds.Further, birds reared on the floor appear less likely to harbor and shed Salmonella, as litter may serve as a seeding agent for competitive exclusion by other microorganisms.Cages for laying hens used in egg production have met with substantial opposition due to welfare concerns and caging broiler chickens will likely be subject to the same kinds of social disapproval.

View Article: PubMed Central - PubMed

Affiliation: Humane Society International, Farm Animals, 2100 L St. NW, Washington, DC 20037, USA. sshields@hsi.org.

ABSTRACT
In most areas of the world, broiler chickens are raised in floor systems, but cage confinement is becoming more common. The welfare of broiler chickens in cages is affected by movement restriction, poor bone strength due to lack of exercise, and prevention of key behavioral patterns such as dustbathing and ground scratching. Cages for broiler chickens also have a long history of causing skin and leg conditions that could further compromise welfare, but a lack of controlled studies makes it difficult to draw conclusions about newer cage designs. Cage environments are usually stocked at a higher density than open floor systems, and the limited studies available suggest that caging may lead to increased levels of fear and stress in the birds. Further, birds reared on the floor appear less likely to harbor and shed Salmonella, as litter may serve as a seeding agent for competitive exclusion by other microorganisms. Cages for laying hens used in egg production have met with substantial opposition due to welfare concerns and caging broiler chickens will likely be subject to the same kinds of social disapproval.

No MeSH data available.


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Broiler chickens in cage with plastic flooring (Photo by Sonia Faruqi).
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animals-03-00386-f002: Broiler chickens in cage with plastic flooring (Photo by Sonia Faruqi).

Mentions: Lack of activity has been associated with gait and skeletal disorders [1,47]. Broiler chickens housed in cages have a greater prevalence of gait problems, impaired walking ability and leg abnormalities (Figure 2) than those raised on the floor [1,30,48]. Starting broiler chicks in battery cages has been associated with a higher incidence of twisted legs before eight weeks of age [49]. Rizk et al. (1980) found that broilers reared in battery cages had a 20 to 60% incidence of perosis-curled toes compared to 12 to 13% for birds in floor-pens [48]. Reece et al. (1971) used a plastic mat to cover the wire-mesh bottom of cages, but still found significantly more of a perosis-like condition in the joint between the tibia and the metatarsus [4]. Haye and Simons (1978) tested the effect of various types of cage floor materials on leg problems, including plastic sheets, mats on wire, and covered wire mesh, and found that broiler chickens had more twisted legs in cages as compared to floor reared birds on litter, although metal wire and perforated metal sheets were worse than plastic or plastic-coated wire [1]. Using gait scoring from 0 (no gait impairment) to 5 (total immobility), Fouad et al. (2008) found that the proportion of birds with score 0 was higher in floor reared birds (72%) compared to those confined to a cage (48%), however no details on the floor or cage type tested were reported [30]. Cage equipment manufacturers claim that their designs no longer cause leg problems, and so additional published research is needed. Given the association between lack of exercise and leg problems, if cages restrict movement then leg condition may be problematic regardless of floor type.


Animal Welfare and Food Safety Aspects of Confining Broiler Chickens to Cages.

Shields S, Greger M - Animals (Basel) (2013)

Broiler chickens in cage with plastic flooring (Photo by Sonia Faruqi).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494387&req=5

animals-03-00386-f002: Broiler chickens in cage with plastic flooring (Photo by Sonia Faruqi).
Mentions: Lack of activity has been associated with gait and skeletal disorders [1,47]. Broiler chickens housed in cages have a greater prevalence of gait problems, impaired walking ability and leg abnormalities (Figure 2) than those raised on the floor [1,30,48]. Starting broiler chicks in battery cages has been associated with a higher incidence of twisted legs before eight weeks of age [49]. Rizk et al. (1980) found that broilers reared in battery cages had a 20 to 60% incidence of perosis-curled toes compared to 12 to 13% for birds in floor-pens [48]. Reece et al. (1971) used a plastic mat to cover the wire-mesh bottom of cages, but still found significantly more of a perosis-like condition in the joint between the tibia and the metatarsus [4]. Haye and Simons (1978) tested the effect of various types of cage floor materials on leg problems, including plastic sheets, mats on wire, and covered wire mesh, and found that broiler chickens had more twisted legs in cages as compared to floor reared birds on litter, although metal wire and perforated metal sheets were worse than plastic or plastic-coated wire [1]. Using gait scoring from 0 (no gait impairment) to 5 (total immobility), Fouad et al. (2008) found that the proportion of birds with score 0 was higher in floor reared birds (72%) compared to those confined to a cage (48%), however no details on the floor or cage type tested were reported [30]. Cage equipment manufacturers claim that their designs no longer cause leg problems, and so additional published research is needed. Given the association between lack of exercise and leg problems, if cages restrict movement then leg condition may be problematic regardless of floor type.

Bottom Line: Cage environments are usually stocked at a higher density than open floor systems, and the limited studies available suggest that caging may lead to increased levels of fear and stress in the birds.Further, birds reared on the floor appear less likely to harbor and shed Salmonella, as litter may serve as a seeding agent for competitive exclusion by other microorganisms.Cages for laying hens used in egg production have met with substantial opposition due to welfare concerns and caging broiler chickens will likely be subject to the same kinds of social disapproval.

View Article: PubMed Central - PubMed

Affiliation: Humane Society International, Farm Animals, 2100 L St. NW, Washington, DC 20037, USA. sshields@hsi.org.

ABSTRACT
In most areas of the world, broiler chickens are raised in floor systems, but cage confinement is becoming more common. The welfare of broiler chickens in cages is affected by movement restriction, poor bone strength due to lack of exercise, and prevention of key behavioral patterns such as dustbathing and ground scratching. Cages for broiler chickens also have a long history of causing skin and leg conditions that could further compromise welfare, but a lack of controlled studies makes it difficult to draw conclusions about newer cage designs. Cage environments are usually stocked at a higher density than open floor systems, and the limited studies available suggest that caging may lead to increased levels of fear and stress in the birds. Further, birds reared on the floor appear less likely to harbor and shed Salmonella, as litter may serve as a seeding agent for competitive exclusion by other microorganisms. Cages for laying hens used in egg production have met with substantial opposition due to welfare concerns and caging broiler chickens will likely be subject to the same kinds of social disapproval.

No MeSH data available.


Related in: MedlinePlus