One common condition is called CLF - or caged layer fatigue. According to Poultry Digest, birds with CLF withdraw minerals from their bones and muscles and eventually are unable to stand. These fatigued birds have brittle or broken bones. Caged production does not merely cause disease, it actually kills the birds. This adds up to a loss of 12 to 18 per cent of the original flock by the end of the first year in cages.
Factory farmed animals are vulnerable to less obvious hazards also.
Young chicks die of thirst because they do not learn to drink from nipple type watering devices. They can starve to death because of debeaking. Caged birds often develop foot and leg problems as a result of months of standing on a wire mesh which is efficient for collection of droppings, but a totally unsuitable perch for the bird. Broilers also develop leg problems because of the inhumane breeding to maximise meat production. A modem broiler reaches its slaughter weight in just 42 days, whidi is twice and fast as it used to be.