battery cage
n.— «There are some 19 million egg-laying hens raised in the state, and Shapiro said more than 90 percent are raised in what are called “battery cages.” The cages are lined up in long rows and on average hold six birds.» —“Humane Society seeks cage-free farms” by Suzanne Bohan The Argus (Fremont, California) Feb. 29, 2008. (source: Double-Tongued Dictionary)