Within U.S. animal agriculture, the majority of egg-laying hens, pregnant sows, and calves raised for veal are reared in battery cages, gestation crates, and veal crates, respectively. The intensive confinement of these production systems severely impairs the animals’ welfare, as they are unable to exercise, fully extend their limbs, or engage in many important natural behaviors. As a result of the severe restriction within these barren confinement systems, animals can experience significant and prolonged physical and psychological assaults. Indeed, extensive scientific evidence shows that intensively confined farm animals are frustrated, distressed, and suffering.
The Humane Society of the United States, "The Welfare of Intensively Confined Animals in Battery Cages, Gestation Crates, and Veal Crates" (2012). IMPACTS ON FARM ANIMALS. 15.