Over the last few decades, commercial chickens have been genetically selected for their performance traits like growth rate, egg colour, or feed efficiency. By concentrating on these traits, chicken breeders may have neglected certain problematic behaviours that not only are causing losses to the industry, but pose significant welfare issues as well.
Feather pecking, which often leads to cannibalism, has long been seen as a problem associated with commercial chickens, and until recently the only methods used to prevent the behaviour were management practices such as beak-trimming and keeping chickens in individual cages.
Recent research suggests chickens may be genetically predisposed to either peck or be pecked and that there may be a way to select chickens in order to reduce the likelihood of feather pecking within a group. The behavioural consequences of selecting against feather pecking pose an interesting question.
By selecting against chickens that displayed aggressing pecking behaviour, researchers found that the resulting generations were far less likely to peck aggressively; they also found, however, that the new generations were less responsive to stressful environments, less fearful, and also less sociable. These behaviours were described as unnatural and, as such, problematic in themselves.
So we are faced with a question. Do we leave commercial chickens to behave “naturally” and continue trimming their beaks and keeping them caged, or do we alter them genetically to prevent feather pecking and potential cannibalism?
Aggression is a trait that has been “bred out” of many different species, including our best friends, dogs – why not chickens?
Josephine Clapham
Primary Source:
- Selection method and early-life history affect behavioural development, feather pecking and cannibalism in laying hens: A review.
- Applied Animal Behaviour Science , Volume 110 , Issue 3 - 4 , Pages 217 - 228
http://www.genetics.org.uk/files/pdf/Issue%2050.pdf
http://www.nature.com.ezproxy.library.uq.edu.au/nature/journal/v431/n7009/pdf/431645a.pdf
http://www.organic-vet.reading.ac.uk/Poultryweb/disease/feath/feath.htm
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