Sometimes hens lay shell-less eggs, which, since they can't be sold, cost the egg producers money. To investigate possible causes, researchers jammed various types of foreign objects, including inflated balloons, shell membranes extracted from other hens, and three different brands of commercial tampons through the cloaca (the external opening on a chicken which receives both feces and eggs or sperm) and into the uteri of hens. Most of the hens died within 48 hours of insertion, suffering from high fever, vomiting, diarrhea, and even a punctured uterus. What beneficial knowledge was gained from this methodical, callous torture I cannot say, and the only conclusions the researchers mustered was that hens might make good models for Toxic Shock Syndrome in humans.
Researchers looking for ways to reduce aggression and feed consumption among caged laying hens are experimenting with red contact lenses. In one study, "considerable mortality" was attributed to the hens' inability to find food or water. They died of hunger and thirst while the researchers watched. In another, cheap plastic lenses caused severe eye infections and even blindness in the test hens, who received no veterinary attention or treatment in the months and months that they suffered.
Air Force training classes teach soldiers "survival skills" using tame farm animals like chickens, rabbits, and goats which they hunt, kill, cook, and eat. It seems ludicrous that these exercises will prepare soldiers for hunting wild animals in a real life survival situation, but there it is, and it costs taxpayers $10,000 a year.
To read about more experiments, look in Poultry Science, Journal of Applied Poultry Research.
