The phrase "battery hens" refers to hens or female chickens that are kept in small, confined cages in large quantities for egg production. Full definition
If they come from battery hens then you'd get more nutritional value from cardboard. (fitnessandpower.com)
You don't have to be a zealous animal rights activist to cringe every time you see images of battery hens, and imagine what a life — even with the very basic mental life of a chicken — would be like in a tiny, crowded cage. (canadianbusiness.com)
Australia should ban battery hens as in countries like Canada, New Zealand, Switzerland and Austria. (afsa.org.au)