Blind Chickens?

Animal welfare in agriculture is constantly under scrutiny. Many choices that are made to increase the overall welfare of animals are condemned for violating one of the 5 freedoms, normally people are most up in arms about violating the freedom to exhibit natural behaviors that is sometimes referred to the freedom of movement. An example is gestation stalls: stalls that limit the movement of a mother sow to only being able to stand up and lie down but allow her piglets to get away from their mother and dramatically decreases the number of piglets that die from being crushed.

Aggression in chickens like layers is a major problem in the table egg industry. This issues is found in birds kept in battery cage systems and in aviary systems, so the amount of space they're given doesn't solve the problem. One solution that has been proposed is genetically blind chickens. These birds have a highly reduced aggression to other birds because they can't see them. Laying hens are also normally very flighty or anxious and not having sight also decreases their stress levels when humans are around.

These birds seem to be an obvious choice to increase animal welfare overall with no adverse effects on production since visual light cues are not needed for photostimulation since there are photo-receptors in the penial gland in the birds brains. Though this seems like a good idea there is a debate about whether or not "taking away" the birds sight is ethical. Many people claim that if blindness in humans isn't considered a cruelty why would blindness in chickens be?

So should consumer opinion of scientific analysis of welfare be the deciding factor? Other advances like the ones Laura Duncan talks about in her blog regarding Temple Grandin and her animal handling facility designs are great ways to improve animal welfare in agriculture.